The World Health Organization Reporting System for Pancreaticobiliary Cytopathology: Overview and Summary

The recently published WHO Reporting System for Pancreaticobiliary Cytopathology (World Health Organization [WHO] System) is an international approach to the standardized reporting of pancreaticobiliary cytopathology, updating the Papanicolaou Society of Cytopathology System for Reporting Pancreaticobiliary Cytology (PSC System). Significant changes were made to the categorization of benign neoplasms, intraductal neoplasms, mucinous cystic neoplasms, and malignant neoplasms considered low grade. Benign neoplasms, such as serous cystadenoma, categorized as Neoplastic: benign in the PSC system, are categorized as Benign/negative for malignancy in the WHO system. Pancreatic neuroendocrine tumor, solid-pseudopapillary neoplasm, and gastrointestinal stromal tumor, categorized as Neoplastic: other in the PSC system, are categorized as Malignant in the WHO System in accord with their classification in the 5th edition WHO Classification of Digestive System Tumours (2019). The two new categories of Pancreaticobiliary Neoplasm Low-risk/grade and Pancreaticobiliary Neoplasm High-risk/grade are mostly limited to intraductal neoplasms and mucinous cystic neoplasms. Low-risk/grade lesions are mucinous cysts, with or without low-grade epithelial atypia. High-risk/grade lesions contain neoplastic epithelium with high-grade epithelial atypia. Correlation with clinical, imaging, and ancillary studies remains a key tenet. The sections for each entity are written to highlight key cytopathological features and cytopathological differential diagnoses with the pathologist working in low resource setting in mind. Each section also includes the most pertinent ancillary studies useful for the differential diagnosis. Sample reports are provided for each category. Finally, the book provides a separate section with risk of malignancy and management recommendations for each category to facilitate decision-making for clinicians.

Grading Cytological Epithelial Atypia in Pancreatic Mucinous Cysts Predicts Patient Survival: Correlation with Histological, Molecular, and Clinical Follow-Up

Cytological examination of epithelial cells in cyst fluids from pancreatic mucinous cysts is the optimal method for identifying high-grade atypia (HGA), which may represent histological high-grade dysplasia (HGD) or invasive carcinoma, and thereby classify the cyst as high-risk, warranting surgical resection. Cytological features of HGA were previously described at our institution in 2013 and implemented thereafter, but performance of grading with these criteria has not yet been reported. 1322 pancreatic cyst fluid specimens (2014-2021) were identified; all pathology reports and relevant clinical data were reviewed in detail. 230 unique cysts (217 patients) contained neoplastic mucinous epithelium. Of the 230 cysts, 178 had low-grade atypia (LGA), and 52 had HGA. 97 cysts had histologic follow-up: 77 (79%) were resections and 20 (21%) were diagnostic surgical biopsies only. 92 (95%) were confirmed neoplastic mucinous cysts, 3 were adenocarcinomas, and 2 were benign entities. Among histologically confirmed neoplastic mucinous cysts, 58 had low-grade dysplasia (LGD); 34 had HGD, of which 14 also had invasive carcinoma. A significantly higher proportion of cysts with HGA (63%) demonstrated at least HGD on follow-up compared to those with LGA (26%, p<0.001). The sensitivity and specificity of HGA for accurately classifying a high-risk cyst were 54% and 81%, respectively. 146/230 (64%) cysts had corresponding next-generation sequencing results. 31% of HGA cysts harbored a high-risk mutation (TP53, CDKN2A, and/or SMAD4) vs. 7% of LGA cysts (p<0.001). Among cysts without histologic confirmation, 25% of HGA cysts had a high-risk mutation vs. 7% of LGA cysts. The grade of cytological atypia was predictive of overall survival and recurrence-free survival (p<0.001 and p=0.020, respectively). Implementation of cytological criteria for HGA in pancreatic mucinous cysts has relatively low sensitivity but modest specificity for classifying a high-risk cyst. Though high-risk mutations were more commonly found in cysts with HGA, their frequency is overall low. Thus, evaluating the degree of cytologic atypia, which is predictive of patient survival, provides significant value and informs patient outcomes.

Diagnostic terminology for benign/low-risk tumors on renal cytology

Biopsy of benign and low-risk tumors of the kidney can be grouped into three distinct categories with different levels of risk, and the suggested diagnoses of these tumors should be tailored to their respective category.

Risk of malignancy in renal biopsy: A review

The risks of malignancy for cytologic categories in renal biopsy specimens differ from the risks in most other sites. There are obvious areas in which cytopathologists can do better at classifying these cases, and the routine use of immunohistochemistry and core-needle biopsy may improve the accuracy of the classification of these specimens.

Low-risk oncocytic renal neoplasm: A useful cytologic diagnosis

The proposed diagnostic category of “low‐risk oncocytic renal neoplasm” consists of both oncocytomas and a subset of chromophobe renal cell carcinomas but has a 5‐year survival of at least 95%–100%.

The World Health Organization Reporting System for Pancreaticobiliary Cytopathology

CONTEXT.—

The World Health Organization (WHO) Reporting System for Pancreaticobiliary Cytopathology (WHO System) is the product of a joint venture between the World Health Organization, the International Academy of Cytology, and the International Agency for Research on Cancer. The WHO System revises the Papanicolaou Society of Cytopathology System for Reporting Pancreaticobiliary Cytology (PSC System) and replaces the 6-tiered system with a 7-tiered system.

OBJECTIVE.—

To explain the WHO System and the differences with the PSC System.

DATA SOURCES.—

The WHO System and the PSC System of Reporting Pancreaticobiliary Cytopathology.

CONCLUSIONS.—

The diagnostic categories of the WHO System are "Insufficient/Inadequate/Nondiagnostic"; "Benign (Negative for Malignancy"'; "Atypical"; "Pancreaticobiliary Neoplasm, Low Risk/Low Grade (PaN-Low)"; "Pancreatic Neoplasm, High Risk/High Grade (PaN-High)"; "Suspicious for Malignancy"; and "Malignant." In the WHO System, the "benign" category includes both nonneoplastic and neoplastic lesions, so the "Neoplastic: Benign" category of the PSC system has been eliminated. Low-grade malignancies, pancreatic neuroendocrine tumors (PanNETs), and solid-pseudopapillary neoplasm (SPN) classified as "Neoplastic: Other" in the PSC System are classified as "Malignant" in the WHO System, leaving in the "Neoplasm" category intraductal lesions, which are divided into 2 new diagnostic categories: "Pancreaticobiliary Neoplasm (PaN)-Low Risk/Grade" and "PaN-High Risk/Grade." As with the PSC System, the WHO System advocates close correlation with imaging and encourages incorporation of ancillary testing into the final diagnosis, such as biochemical (carcinoembryonic antigen [CEA] and amylase) and molecular testing. The WHO System includes risk of malignancy per category, and reporting and diagnostic management options that recognize the variations in resources of low- and middle-income countries.

One procedure-one report: the Re-Imagine Cytopathology Task Force position paper on small tissue biopsy triage in anatomic pathology

INTRODUCTION

Endoscopic biopsy procedures increasingly generate multiple tissue samples from multiple sites, and frequently retrieve concurrent cytologic specimens and small core needle biopsies. There is currently lack of consensus in subspecialized practices as to whether cytopathologists or surgical pathologists should review such samples, and whether the pathology findings should be reported together or separately.

MATERIALS AND METHODS

In December 2021, the American Society of Cytopathology convened the Re-Imagine Cytopathology Task Force to examine various workflows that would facilitate unified pathology reporting of concurrently obtained biopsies and improve clinical care.

RESULTS AND CONCLUSIONS

This position paper summarizes the key points and highlights the advantages, challenges, and resources available to support the implementation of such workflows that result in "one procedure-one report".

Systematic review of challenging issues in pathology of intraductal papillary mucinous neoplasms

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are a cystic precursor to pancreatic cancer. IPMNs deemed clinically to be at high-risk for malignant progression are frequently treated with surgical resection, and pathological examination of the pancreatectomy specimen is a key component of the clinical care of IPMN patients.

METHODS

Systematic literature reviews were conducted around eight topics of clinical relevance in the examination of pathological specimens in patients undergoing resection of IPMN.

RESULTS

This review provides updated perspectives on morphological subtyping of IPMNs, classification of intraductal oncocytic papillary neoplasms, nomenclature for high-grade dysplasia, assessment of T stage, distinction of carcinoma associated or concomitant with IPMN, role of molecular assessment of IPMN tissue, role of intraoperative assessment by frozen section, and preoperative evaluation of cyst fluid cytology.

CONCLUSIONS

This analysis provides the foundation for data-driven approaches to several challenging issues in the pathology of IPMNs.

A brief review of the WHO reporting system for pancreaticobiliary cytopathology

The World Health Organization (WHO), the International Academy of Cytology, and the International Agency for Research on Cancer have developed an approach to standardized reporting of pancreaticobiliary cytopathology. The WHO Reporting System for Pancreaticobiliary Cytopathology (WHO System) revises the Papanicolaou Society of Cytopathology (PSC) System for Reporting Pancreaticobiliary Cytology published in 2015 and replaces the 6 PSC categories with 7 categories: "Insufficient/Inadequate/Nondiagnostic"; "Benign/Negative for malignancy"; "Atypical"; "Pancreaticobiliary neoplasm, low risk/grade (PaN-low)"; "Pancreatic neoplasm, high risk/grade (PaN-High)"; "Suspicious for malignancy"; and "Malignant". In the PSC system, there is a single category for "Neoplastic" lesions that includes 2 groups, 1 for benign neoplasms and 1 named "Neoplastic-other", dominated by premalignant intraductal neoplasms primarily intraductal papillary mucinous neoplasms and low-grade malignant neoplasms (pancreatic neuroendocrine tumors (PanNET) and solid pseudopapillary neoplasms (SPN). In the WHO System, benign neoplasms with virtually no risk of malignancy are included in the "Benign" category and low-grade malignancies (PanNET and SPN) are included in the "Malignant" category, as per the 5th edition of the WHO Classification of Digestive System Tumors, while the non-invasive pre-malignant lesions of the ducts are divided by the cytomorphological grade of the epithelium into PaN-low and PaN-high with distinctly different risks of malignancy. Within each category, key diagnostic cytopathologic features and the ancillary studies for diagnostic and prognostic evaluation, as well as the implications of diagnosis for patient care and management, are outlined. Reporting and diagnostic management options recognize the variations in the availability of diagnostic and prognostic ancillary testing modalities in low- and middle-income countries.

A brief review of the WHO reporting system for lung cytopathology

The International Academy of Cytology has joined with the International Agency for Research on Cancer to bring together a group of experts in lung cytopathology to develop a WHO Reporting System for Lung Cytopathology (WHO System). This System aims to improve and standardize the reporting of cytopathology, facilitate communication between cytopathologists and clinicians, and improve patient care. The WHO System describes 5 categories for reporting lung cytopathology: 'Insufficient/Inadequate/Nondiagnostic', 'Benign', 'Atypical', 'Suspicious for malignancy', and 'Malignant', each one with a clear descriptive term, a definition, a risk of malignancy, and a suggested management algorithm. The key diagnostic cytopathologic features of each of the lesions within each category have been established by consensus through an Expert Editorial Board, who are also the authors of this review and selected for each reporting system and chosen based on their expertise in the field and/or diversity of geographical representation. Many other co-authors from around the world also contributed. The assignment of writing and editing responsibilities used the same model as that used for the WHO Classification of Tumours (https://whobluebooks.iarc.fr/about/faq/). The WHO System provides the best practice application of ancillary testing, including immunocytochemistry and molecular pathology, and guides in sampling and processing techniques to optimize the handling and preparation of specimens. The WHO System was created by the authors to be applicable globally and is based on cytomorphology with possibilities for additional diagnostic management of the patient. The authors are aware that local medical and pathology resources would differ, especially in low- and middle-income countries. The WHO Tumour Classification for Thoracic Tumors, Fifth Edition, is directly accessible through the online WHO System.

The World Health Organization Reporting System for Pancreaticobiliary Cytopathology

The World Health Organization (WHO), the International Academy of Cytology, and the International Agency for Research on Cancer, with expert contributors from around the world, present an international approach to standardized reporting of pancreaticobiliary cytopathology. This reporting system is one of the first in a series from various body sites that mirror the WHO Classification of Tumours series and provides an evidence-based terminology system with associated risk of malignancy and diagnostic management recommendation per diagnostic category. The WHO Reporting System for Pancreaticobiliary Cytopathology (WHO system) revises the Papanicolaou Society of Cytopathology (PSC) system for Reporting Pancreaticobiliary Cytology published in 2015 and replaces the six-tiered system with a seven-tiered system: "insufficient/inadequate/nondiagnostic"; "benign (negative for malignancy)," "atypical," "pancreaticobiliary neoplasm of low risk/low grade," "pancreatic neoplasm of high risk/high grade," "suspicious for malignancy," and "malignant." The principal differences between the WHO and the PSC systems revolve around the classification of neoplasia. In the PSC system, there was a single category for "neoplastic" lesions that includes two groups, one for "benign neoplasms" [primarily serous cystadenoma] and one named "other," dominated by premalignant intraductal neoplasms (primarily intraductal papillary mucinous neoplasms) and low-grade malignant neoplasms [pancreatic neuroendocrine tumors (PanNETs) and solid pseudopapillary neoplasms (SPNs)]. In the WHO system, benign neoplasms with virtually no risk of malignancy are included in the "benign" category and low-grade malignancies (PanNET and SPN) are included in the "malignant" category, as per the WHO Classification of Digestive System Tumours, thus leaving in the "neoplasm" category primarily those noninvasive premalignant lesions of the ductal system. These neoplasms are divided by the cytomorphological grade of the epithelium into low risk/low-grade and high risk/high-grade, with distinctly different risks of malignancy. As with the PSC system, the WHO system advocates close correlation with imaging and encourages incorporation of ancillary testing into the final diagnosis, such as biochemical (CEA and amylase) and molecular testing of cyst fluid and bile duct brushings. Key diagnostic cytopathological features of specific lesions or neoplasms, ancillary studies for diagnostic and prognostic evaluation, and implications of diagnosis for patient care and management are discussed. In addition, the WHO system includes reporting and diagnostic management options that recognize the variations in the availability of diagnostic and prognostic ancillary testing modalities in low- and middle-income countries, where cytopathology is particularly useful and is increasingly available in the absence of histopathological services.

The World Health Organization Reporting System for Lung Cytopathology

The International Academy of Cytology has joined with the International Agency for Research on Cancer (IARC) to bring together a group of experts in lung cytopathology to develop a WHO Reporting System for Lung Cytopathology (WHO System). This WHO System defines five categories for reporting lung cytopathology, that is, "Insufficient"/"Inadequate"/"Non-diagnostic," "Benign," "Atypical," "Suspicious for malignancy," and "Malignant," each with a clear descriptive term for the category, a definition, a risk of malignancy and a suggested management algorithm. The key diagnostic cytopathology features of each of the lesions within each category have been established by consensus and will be presented more fully in a subsequent IARC e-book and published hard cover book.The WHO System provides the best practice application of ancillary testing, including immunocytochemistry and molecular pathology, and provides a review to guide sampling and processing techniques to optimize the handling and preparation of the cytopathology sample emphasizing the cytomorphological differential diagnosis to aid low-resourced settings. The authors recognize that local medical and pathology resources will vary, particularly in low- and middle-income countries, and have developed the WHO System to make it applicable worldwide based on cytomorphology with options for further diagnostic management of the patient.The online WHO System provides a direct link to the WHO Tumour Classification for Thoracic Tumours 5th Edition. It will raise the profile and use of cytopathology by increasing awareness of its current role and its potential role in the era of personalized medicine based on molecular pathology utilizing "small biopsies." Ultimately, the System will improve patient care and outcomes.This System aims to improve and standardize the reporting of cytopathology, facilitate communication between cytopathologists and clinicians and improve patient care. The System is based on the current role of lung cytopathology and synthesizes the existing evidence while highlighting areas requiring further research and the future potential role of lung cytopathology.

The Cytomorphologic and Molecular Assessment of Bile Duct Brushing Specimens

Biliary duct brushing cytology is the standard of care for the assessment of bile duct strictures but suffers from low sensitivity for the detection of a high-risk stricture. Pathologic diagnosis of strictures is optimized by integration of cytomorphology and molecular analysis with fluorescence in situ hybridization or next-generation sequencing. Bile duct cancers are genetically heterogeneous, requiring analysis of multiple gene panels to increase sensitivity. Using molecular analysis as an ancillary test for bile duct brushing samples aids in the identification of mutations that support the diagnosis of a high-risk stricture as well as the identification of actionable mutations for targeted therapies currently in clinical trials for the treatment of patients with bile duct cancer.

The value of monitoring amended reports in cytopathology quality programs: A biennial review

BACKGROUND

Quality and safety are the foundation of the practice of cytopathology. Review of key performance indicator (KPI) data can shine a light on laboratory vulnerabilities and potential areas for targeted improvement. The rate and content of amendment reports is a frequently monitored KPI in anatomic pathology, but few have studied its value in cytopathology. The goal of this study was to examine the frequency, classification, and outcome of amendments for a large cytopathology laboratory.

METHODS

All amendment reports issued for cases during a 2-year period from July 2019 to June 2021 were included in the study. Amendments were classified into three error type root causes: Specimen Identification Error, General Report Defects, and Diagnostic Error.

RESULTS

A total of 202 amendment reports were issued equating to a rate of 0.275%. A total of 83 (41.1%) were gynecologic cases and 119 (58.9%) were nongynecologic cases. Within the gynecologic cases, 13 (15.7%) cases were due to Specimen Identification Error, 13 (15.7%) cases were due to Diagnostic Error, and 57 (68.7%) cases were due to General Report Defects. Within the nongynecologic cases, 15 (12.6%) cases were due to Specimen Identification Error, 30 (25.2%) cases were due to General Report Defects, and 74 (62.2%) cases were due to Diagnostic Error with 32 of these due to true diagnostic change. Discovery methods included following re-review after additional clinical information was provided, reinterpretation after additional ancillary testing was performed, or conference review. There was no correlation with years in practice.

CONCLUSIONS

Studying amendment reports is an underrecognized and valuable quality assurance tool. Amendments can help provide information about types of errors, monitor laboratory processes, and help guide quality improvement endeavors.

Risk of malignancy associated with diagnostic categories of the proposed World Health Organization International System for Reporting Pancreaticobiliary Cytopathology

BACKGROUND

The World Health Organization (WHO) has proposed an updated international classification system for reporting pancreaticobiliary cytology. Substantial changes to the prior Papanicolaou Society of Cytopathology (PSC) system have been recommended. Chiefly, the "neoplastic: benign" and "neoplastic: other" categories have been replaced by 2 new categories-"pancreatic neoplasia-low-grade" (PaN-Low) and "pancreatic neoplasia-high-grade" (PaN-High)-stratifying neoplastic mucinous cysts by cytological atypia. Low-grade malignancies are placed in the "malignant" category and benign serous cystadenoma in the "benign/negative" category. Risk of malignancy (ROM) associated with the diagnostic categories of the WHO system has yet to be defined.

METHODS

All patients who underwent endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for a pancreatic lesion at a single institution from January 2016 to December 2016, prospectively classified using the PSC system, were reclassified using the WHO system. Absolute ROM was determined by histologic outcome and/or clinical follow-up of at least 6 months.

RESULTS

A total of 334 EUS-FNA samples from 322 patients were reviewed and reclassified. Absolute ROM for the WHO system was 7.7% for "insufficient/inadequate/nondiagnostic" category, 1.0% for "benign/negative for malignancy," 28.0% for "atypical," 4.8% for "PaN-Low," 60.0% for "PaN-High," 100% for "suspicious for malignancy," and 100% for "malignant;" the absolute ROM for the same cohort using the PSC system was 7.7% for "nondiagnostic" category, 1.0% for "negative (for malignancy)," 28.0% for "atypical," 0.0% for "neoplastic: benign," 30.3% for "neoplastic: other," 100% for "suspicious (for malignancy)," and 100% for "positive or malignant."

CONCLUSIONS

The WHO international system achieves improved stratification by associated ROM compared to the PSC system.

Performance of Rapid On-Site Evaluation in Breast Fine-Needle Aspiration Biopsies: Identifying Areas of Diagnostic Challenge

INTRODUCTION

Fine-needle aspiration (FNA) is a well-established method for sampling breast lesions with high accuracy and positive predictive value. Despite its decline in recent years relative to the use of core needle biopsies, there are several advantages to FNA which include cost-effectiveness, low complication rate, and the ability to perform rapid on-site evaluation (ROSE). The aim of this study was to evaluate breast FNAs with ROSE to identify diagnostic challenges during ROSE.

MATERIALS AND METHODS

We identified all breast FNAs with ROSE performed at Massachusetts General Hospital from January 2014 to December 2019. From the electronic medical record, clinical, radiological, and follow-up pathology results were recorded. Comparison between the rapid and final cytological diagnosis was made. All discrepancies were documented with major discrepancy defined as a malignant rapid interpretation not confirmed on final diagnosis or a negative rapid interpretation upgraded to suspicious or positive on final diagnosis.

RESULTS

The study cohort consisted of 483 breast FNAs with ROSE. The rapid and final cytological interpretations showed good correlation, with only 6 (1.2%) major discrepancies. Problematic areas included low-grade, lobular, and fibroepithelial lesions with low cellularity being a contributory factor to misclassification.

CONCLUSIONS

FNA remains a highly accurate method for the evaluation of breast lesions with ROSE.

Cytology adds value to monoclonal antibody Das-1 testing for detection of high-risk pancreatic cysts

INTRODUCTION

Determining the risk of malignancy in a pancreatic cyst (PC) is a clinical and diagnostic challenge. Monoclonal antibody (mAb) Das-1 test was shown to have high sensitivity, specificity, and accuracy in detecting high-risk (HR) cysts. Das-1 mAb test detects HR mucinous cysts with high-grade dysplasia (HGD), invasive carcinoma, and/or intestinal-type epithelium. Correlation of mAb Das-1 testing of PC fluids with cytomorphologic findings has not been evaluated.

MATERIALS AND METHODS

We correlated cytology with mAb Das-1 test results and resection histology in 26 PCs. There were 18 intraductal papillary mucinous neoplasms (IPMN), 1 intraductal oncocytic papillary neoplasm (IOPN), 4 mucinous cystic neoplasms (MCN), 2 serous cystadenomas, and 1 cystic pancreatic neuroendocrine tumor (PanNET). HR cysts included cysts with high-grade atypia on cytology or HGD on histology, invasive carcinoma, IOPNs, and cystic PanNETs. Intestinal type IPMNs were also HR cysts on histology.

RESULTS

In 17 cases (65.38%), cytology and mAb Das-1 test correlated with histology. There were 2 (7.69%) mAb Das-1 test negative HR PCs diagnosed by cytology. Five (19.23%) mAb Das-1 test positive HR PCs had mucin only or cells with low-grade dysplasia on cytology. Two mAb Das-1 test positive HR PCs had nondiagnostic cytology. HR IOPN and cystic PanNET were not detected by mAb Das-1 test.

CONCLUSION

The mAb Das-1 is a sensitive and specific biomarker for detecting HR mucinous PCs. Adding cytology to mAb Das-1 testing improves the sensitivity for the detection of nonmucinous HR PC. Together, cytology with mAb Das-1 testing is more accurate than either one alone.

Cytopathological Heterogeneity of Circulating Tumor Cells in Non-metastatic Esophageal Adenocarcinoma

BACKGROUND/AIM

The presence of circulating tumor cells (CTC) has been reported to have an impact on prognosis in different tumor entities. Little is known about CTC morphology and heterogeneity.

PATIENTS AND METHODS

In a multicenter setting, pre-therapeutic peripheral blood specimens were drawn from patients with non-metastatic esophageal adenocarcinoma (EAC). CTCs were captured by size-based filtration (ScreenCell®), subsequently Giemsa-stained and evaluated by two trained readers. The isolated cells were categorized in groups based on morphologic criteria.

RESULTS

Small and large single CTCs, as well as CTC-clusters, were observed in 69.2% (n=81) of the 117 specimens; small CTCs were observed most frequently (59%; n=69), followed by large CTCs (40%; n=47) and circulating cancer-associated macrophage-like cells (CAMLs; 34.2%, n=40). Clusters were rather rare (12%; n=14). CTC/CAML were heterogeneous in the cohort, but also within one specimen. Neither the presence of the CTC subtypes/CAMLs nor the exact cell count were associated with the primary clinical TNM stage.

CONCLUSION

Morphologically heterogenic CTCs and CAMLs are present in patients with non-metastatic, non-pretreated EAC.

Determining the significance of psammoma bodies in pelvic washings: A 10-year retrospective review

BACKGROUND

Pelvic washing specimens are relatively common and are submitted for patients undergoing gynecologic surgery to evaluate them for metastatic or occult disease. Psammoma bodies are a relatively uncommon finding in these specimens. To date, large-scale studies of their cytologic-histologic correlates and thus clinical significance have been limited.

METHODS

A 10-year retrospective search for all pelvic washing specimens was performed, and all cases were reviewed for the presence of psammoma bodies. The findings for the corresponding surgical pathology specimens were then catalogued.

RESULTS

Psammoma bodies were present in 138 cases (3.6% of 3840 total pelvic washings). More than half of the cases (n = 73 [53%]) were associated with benign processes, including mesothelial hyperplasia (n = 44), endosalpingiosis (n = 11), endometriosis (n = 11), and ovarian cystadenoma/cystadenofibroma (n = 7). Nineteen cases (14%) were associated with serous borderline tumors. Malignancies were noted in a third of the cases (n = 46 [33%]) and were most frequently low-grade serous adenocarcinomas (n = 15), high-grade serous adenocarcinomas (n = 11), or endometrioid endometrial carcinomas (n = 8). Patients found to have benign processes (median age, 50 years) or borderline disease (median age, 56 years) were significantly younger than patients with malignancies (median age, 65 years; P < .0001). In addition, the correlation of cytologic interpretation categories with concurrent histopathologic findings showed that cytologic analysis was highly sensitive and specific in determining the nature of underlying processes.

CONCLUSIONS

The majority of psammoma bodies noted in pelvic washings were associated with benign processes or borderline tumors, with approximately a third of the cases associated with malignancies. Psammoma bodies in pelvic washings from younger patients were significantly more likely to be associated with benign processes or borderline tumors.

Evaluating triage protocols for endoscopic ultrasound-guided fine needle biopsies of the pancreas

INTRODUCTION

Pancreatic endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) acquires both direct smear and small core biopsy specimens. The triage protocols for pancreatic FNBs to cytopathology (CP) or gastrointestinal surgical pathology (GIP) are controversial and vary by institution.

MATERIAL AND METHODS

Pancreatic EUS-FNBs obtained with the SharkCore FNB were reviewed from January 2014 to June 2019. The specimen characteristics and pathology data, including tissue triage, were obtained from the electronic medical records. We assessed the diagnostic yield, defined as malignant, specific neoplastic, or benign, and the operating characteristics at the time of rapid on-site evaluation (ROSE) and final diagnosis.

RESULTS

We reviewed 324 pancreatic FNBs from 313 patients. Of the 324 FNBs, 260 (80%) obtained concurrent direct smear and core biopsy specimens, 30 (12%) of which were divided between CP and GIP. Of the 51 core-only specimens, 47 (92%) were reviewed by CP and 4 (8%) by GIP. ROSE improved the overall diagnostic yield by 10% and accuracy by 9%. When core specimens were reviewed independently, the diagnostic accuracy was 93% for CP (n = 248) and 100% for GIP (n = 33). All false-negative results of the CP-reviewed cores were due to sampling error. Concurrent smear review improved EUS-FNB performance, increasing the negative predictive value by 10% and accuracy by 3% compared with core review alone.

CONCLUSIONS

CP and GIP can accurately interpret pancreatic EUS-FNB specimens. However, triage of concurrent EUS-FNB-acquired smear and core specimens to CP may be most efficient as CPs are trained to assess adequacy at the time of ROSE, as well as interpret all parts of the biopsy, minimizing the risk of discordant pathology reports.

Cytomorphologic characteristics of next-generation sequencing-positive bile duct brushing specimens

INTRODUCTION

Cytology of bile duct brushings (BDBs) is a specific, but insensitive, test for malignancy. Next-generation sequencing (NGS) of BDBs has recently been shown to improve sensitivity. We analyzed the cytologic features of NGS-positive (NGS⁺) and NGS-negative (NGS^-) BDBs and correlated the morphology with the presence of mutations.

MATERIALS AND METHODS

A total of 96 BDBs were analyzed for 29 cytologic features by 2 pathologists who were unaware of the original diagnosis and NGS results. Clinicopathologic follow-up was used to determine the patient outcomes (ie, benign, low-grade neoplasm, malignant [carcinoma/high-grade dysplasia]).

RESULTS

We analyzed 74 NGS⁺ BDBs from 66 patients and 22 NGS^- BDBs from 22 patients. During follow-up, 58 of 66 NGS⁺ patients (88%) had malignancy compared with 0% of NGS^- patients (P < 0.001). Fewer than 50% of the malignant cases had been interpreted as malignant on cytology; however, 100% had demonstrated mutations using NGS. Within the NGS⁺ cases, 53% showed late mutations (TP53, SMAD4, and CDKN2A) supportive of a high-risk stricture. Significant morphologic differences were seen in the background appearance, presence of single cells, architectural disarray, nucleomegaly, anisonucleosis, irregular nuclear borders, increased nuclear/cytoplasmic ratio, nuclear hyperchromasia, nucleoli, abnormal groups, clusters, and/or single cells, and overall impression. Naked nuclei, nucleomegaly, anisonucleosis, and coarse chromatin were more common in BDBs with late mutations than in those with KRAS/GNAS (Kirsten rat sarcoma viral oncogene homolog/guanine nucleotide binding protein, α-stimulating complex locus) mutations only. Cytology had a sensitivity of 16% and a specificity of 100% for malignancy. In contrast, NGS had a sensitivity of 100% and a specificity of 73%. Late mutations were 100% specific for malignancy compared with mutations in KRAS/GNAS only, of which 69% were malignant.

CONCLUSIONS

We found significant overlap in the cytomorphologic features between neoplastic and non-neoplastic BDBs, and more than one half of cancer cases had been interpreted as "nonmalignant" on cytology. NGS showing late mutations was 100% specific for malignancy. Adding genetic testing to BDB cytology would be a valuable ancillary test for the detection of malignancy, and reflex testing should be considered.

Interpretation pitfalls and malignant mimics in cervical cytology

Cervical cytology has remained a diagnostically challenging area despite its long and widespread use. At least part of this challenge has stemmed from the cytomorphologic overlap between benign and neoplastic processes. The present review has highlighted select benign processes that present diagnostic pitfalls. For each of these, we have discussed the pertinent cytologic features and emphasized the morphologic clues that will aid in distinguishing the benign entities from the neoplastic processes they mimic.

Small core needle biopsies in cytology practice: a survey of members of the American Society of Cytopathology

INTRODUCTION

The introduction of a new generation of core needle biopsies (CNBs) for endoscopic procedures has prompted reconsideration of the role of cytopathologists in the handling of small biopsies. The American Society of Cytopathology (ASC) has therefore conducted a survey with the intention of elucidating current practices regarding the handling of small CNBs.

MATERIALS AND METHODS

The membership of the ASC was invited by email to participate in an online survey over a 2-month period. The survey consisted of 20 multiple choice questions with 2-8 possible responses per question.

RESULTS

Of 2651 members contacted by e-mail, 282 (10.6%) responded to the survey questions, including 196 pathologists (69.5%) and 86 cytotechnologists (30.5%). Of these, 265 respondents were from the US/Canada (94.0%), with 156 from academic institutions (58.9%) and 109 from non-academic practices (41.1%); 17 were from other countries (6.0%). In 18.8% of all practices, cytopathologists sign out >90% of small CNBs from endoscopic and radiologically guided procedures; in 36.5% of practices >90% are signed out by surgical pathologists; the remainder have such cases divided more evenly between cytopathologists and surgical pathologists. Responses show that 78.0% of all respondents are interested in signing out more small biopsies in the future, and 80.5% desire increased small biopsy-related resources from the ASC.

CONCLUSIONS

The survey responses indicate that practices currently vary widely across institutions. Most indicated an interest in greater incorporation of small biopsies into the practice of cytopathology.

Oil red O staining for lipid-laden macrophage index of bronchoalveolar lavage: interobserver agreement and challenges to interpretation

INTRODUCTION

Oil Red O (ORO) staining on cytologic specimens with calculation of the lipid-laden macrophage index (LLMI) is used as a part of the workup in a number of clinical settings, particularly when aspiration is of concern. As a part of ongoing internal quality improvement measures, the objective of the present study was to evaluate the interobserver agreement of the LLMI calculation and to identify factors that affect the variability of the calculation.

MATERIALS AND METHODS

There were 9 study participants, which included 3 trainees, 3 cytotechnologists, and 3 cytopathologists. Each participant reviewed 100 ORO-stained bronchoalveolar lavage slides and assigned an LLMI score to each case. The scores were categorized into 3 groups according to the associated aspiration risk: low, LLMI <40; intermediate, LLMI 40 to 90; and high, LLMI >90. The participants were also requested to note any challenges to the calculation for each case.

RESULTS

The interobserver agreement among all participants was fair (κ = 0.23). Stratified by participant group, the interobserver agreement among the trainees was fair (κ = 0.24), among cytotechnologists was fair (κ = 0.32), and among cytopathologists was moderate (κ = 0.60). In 70 cases, at least one participant scored the case at least one category higher than the other participants; in 47 cases there was a two category difference. A primary diagnostic challenge reported by participants was macrophage pigmentation (hemosiderin, anthracosis).

CONCLUSIONS

We found only fair interobserver agreement among all 9 participants in the study. Hemosiderin and anthracotic pigmentation was a major factor impeding LLMI calculation resulting in overestimation of the LLMI.

Experience and future perspectives on the use of the Papanicolaou Society of Cytopathology Terminology System for reporting pancreaticobiliary cytology

The Papanicolaou Society of Cytopathology developed a set of guidelines for reporting pancreaticobiliary cytology in 2014 (PB System), with a six-tiered system: Nondiagnostic, Negative, Atypical, Neoplastic (Benign or Other), Suspicious, and Positive. This proposed scheme incorporates ancillary testing such as biochemical testing of cyst fluids for diagnosis and provides terminology that standardizes the category of the various diseases of the pancreas, some of which are difficult to diagnose specifically by cytology alone. Since its initial publication five and half years ago, several groups have published their experiences on the use of the PB System and have shown that most objectives proposed by the original publication have been achieved. They have shown that there is a better understanding and definition of the diagnostic categories with an associated distribution and risk of malignancy. The diagnostic categories of Neoplastic: Other, Suspicious, and Malignant show a high sensitivity and specificity for the diagnosis of malignancy. The System also provides a multi-specialist view of pancreatic lesions, with biochemical and radiological findings being incorporated into the final pathological report. The present review summarizes these findings and discusses the future perspectives and foreseen changes that are to be incorporated to a second edition of the reporting System.

Cross Validation of the Monoclonal Antibody Das-1 in Identification of High-Risk Mucinous Pancreatic Cystic Lesions

BACKGROUND & AIMS

Although pancreatic cystic lesions (PCLs) are frequently and incidentally detected, it is a challenge to determine their risk of malignancy. In immunohistochemical and enzyme-linked immunosorbent assay (ELISA) analyses of tissue and cyst fluid from pancreatic intraductal papillary mucinous neoplasms, the monoclonal antibody Das-1 identifies those at risk for malignancy with high levels of specificity and sensitivity. We aimed to validate the ability of Das-1 to identify high-risk PCLs in comparison to clinical guidelines and clinical features, using samples from a multicenter cohort.

METHODS

We obtained cyst fluid samples of 169 PCLs (90 intraductal papillary mucinous neoplasms, 43 mucinous cystic neoplasms, and 36 non-mucinous cysts) from patients undergoing surgery at 4 tertiary referral centers (January 2010 through June 2017). Histology findings from surgical samples, analyzed independently and centrally re-reviewed in a blinded manner, were used as the reference standard. High-risk PCLs were those with invasive carcinomas, high-grade dysplasia, or intestinal-type intraductal papillary mucinous neoplasms with intermediate-grade dysplasia. An ELISA with Das-1 was performed in parallel using banked cyst fluid samples. We evaluated the biomarker's performance, generated area under the curve values, and conducted multivariate logistic regression using clinical and pathology features.

RESULTS

The ELISA for Das-1 identified high-risk PCLs with 88% sensitivity, 99% specificity, and 95% accuracy, at a cutoff optical density value of 0.104. In 10-fold cross-validation analysis with 100 replications, Das-1 identified high-risk PCLs with 88% sensitivity and 98% specificity. The Sendai, Fukuoka, and American Gastroenterological Association guideline criteria identified high-risk PCLs with 46%, 52%, and 74% accuracy (P for comparison to Das-1 ELISA <.001). When we controlled for Das-1 in multivariate regression, main pancreatic duct dilation >5 mm (odds ratio, 14.98; 95% confidence interval, 2.63-108; P < .0012), main pancreatic duct dilation ≥1 cm (odds ratio, 47.9; 95% confidence interval, 6.39-490; P < .0001), and jaundice (odds ratio, 6.16; 95% confidence interval, 1.08-36.7; P = .0397) were significantly associated with high-risk PCLs.

CONCLUSIONS

We validated the ability of an ELISA with the monoclonal antibody Das-1 to detect PCLs at risk for malignancy with high levels of sensitivity and specificity. This biomarker might be used in conjunction with clinical guidelines to identify patients at risk for malignancy.

Risk of malignancy in the categories of the Papanicolaou Society of Cytopathology system for reporting pancreaticobiliary cytology

BACKGROUND

Management of pancreatic lesions depends on the risk of malignancy, which is primarily determined from the cytologic and radiologic evaluation findings. The Papanicolaou Society of Cytopathology (PSC) published a classification system for reporting pancreaticobiliary cytology. However, the "neoplastic: other" category can be further stratified by high-grade atypia (HGA). Studies on the risk of malignancy using the PSC system have been limited.

MATERIALS AND METHODS

All patients who had undergone endoscopic ultrasound-guided fine-needle aspiration (FNA) for a pancreatic lesion at Massachusetts General Hospital from January 2016 to December 2016 were prospectively classified. The clinical, radiographic, and endoscopic findings, cytologic and histologic diagnoses, and follow-up data from 334 FNA biopsies from 322 patients were reviewed. The neoplastic: other category was subclassified as low-grade atypia or HGA. The absolute risk of malignancy was determined by the histologic outcome or follow-up of ≥6 months.

RESULTS

The absolute risk of malignancy was 7.7% for the nondiagnostic category; 1.0% for negative; 28.0% for atypical; 0.0% for neoplastic: benign; 30.3% for neoplastic: other; 90.0% for neoplastic: other with HGA; 100% for suspicious; and 100% for positive. When the neoplastic: other with HGA, suspicious, and positive cytologic diagnoses were considered positive, the sensitivity, specificity, positive predictive value, and negative predictive value for pancreatic FNA biopsy was 92.2%, 98.8%, 98.3%, and 94.3%, respectively.

CONCLUSIONS

Categories of the PSC system each carry an implied absolute risk of malignancy, increasing from the negative to positive categories. The presence of HGA identifies lesions at the greatest risk of malignancy in the neoplastic: other category, and its inclusion with suspicious and positive as positive diagnoses optimizes the diagnostic performance of identifying high-risk lesions that warrant surgical excision.

Non-Metastatic Esophageal Adenocarcinoma: Circulating Tumor Cells in the Course of Multimodal Tumor Treatment

BACKGROUND

Isolation of circulating tumor cells (CTC) holds the promise to improve response-prediction and personalization of cancer treatment. In this study, we test a filtration device for CTC isolation in patients with non-metastatic esophageal adenocarcinoma (EAC) within recent multimodal treatment protocols.

METHODS

Peripheral blood specimens were drawn from EAC patients before and after neoadjuvant chemotherapy (FLOT)/chemoradiation (CROSS) as well as after surgery. Filtration using ScreenCell^® devices captured CTC for cytologic analysis. Giemsa-stained specimens were evaluated by a cytopathologist; the cut-off was 1 CTC/specimen (6 mL). Immunohistochemistry with epithelial (pan-CK) and mesenchymal markers (vimentin) was performed.

RESULTS

Morphologically diverse malignant CTCs were found in 12/20 patients in at least one blood specimen. CTCs were positive for both vimentin and pan-CK. More patients were CTC positive after neoadjuvant therapy (6/20 vs. 9/15) and CTCs per/ml increased in most of the CTC-positive patients. After surgery, 8/13 patients with available blood specimens were still CTC positive. In clinical follow-up, 5/9 patients who died were CTC-positive.

CONCLUSIONS

Detection of CTC by filtration within multimodal treatment protocols of non-metastatic EAC is feasible. The rate of CTC positive findings and the quantity of CTCs changes in the course of multimodal neoadjuvant chemoradiation/chemotherapy and surgery.

Diagnostic yield of the SharkCore EUS-guided fine-needle biopsy

INTRODUCTION

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the standard diagnostic procedure for many intrathoracic and intra-abdominal lesions. Next-generation fine-needle biopsies (FNBs) can increase diagnostic yield by procuring tissue suitable for histological processing. We evaluate the diagnostic yield and operating characteristics of the SharkCore (SC; Medtronic Corp., Minneapolis, MN) FNB in a tertiary referral facility.

MATERIALS AND METHODS

We performed a single-center retrospective review of SC-FNB-acquired tissue between January 2014 and March 2018. Patient demographic data, endoscopic features, and pathology data were obtained from the electronic medical record. Diagnostic yield was assessed by the ability to obtain a definitive diagnosis, defined as malignant or benign interpretations. Operating characteristics were also calculated.

RESULTS

A total of 179 lesions were sampled with the SC-FNB in 157 patients (mean age: 63 years, 57% male). Of these, 31 lesions were concomitantly sampled with a conventional FNA needle. Most lesions were pancreatic (49%). Diagnostic yield was 86%, which was independent of lesion location, lesion size and needle gauge. Diagnostic accuracy was highest when both histology and cytology specimens were analyzed concurrently (96.5%). In patients with a history of chronic pancreatitis, accuracy, sensitivity, and negative predictive value were reduced (71.4%, 20.0%, and 69.2%, respectively). Rapid onsite evaluation (ROSE) occurred in 64.8% of cases and was more likely to be diagnostic at the time of rapid evaluation if SC-acquired tissue was utilized versus FNA-acquired tissue (P = 0.03); however, final diagnostic yield did not differ between needles (P = 0.13).

CONCLUSIONS

SC-FNB shows high diagnostic yield and accuracy and provides diagnostic tissue for ROSE. SC-FNB is an effective alternative to conventional FNA.

Granular cell tumor of the lung

A 46-year-old female with history of asthma, active smoking (20 pack-years), and schizophrenia was evaluated for a persistent asymptomatic pulmonary nodule. Her past medical history was notable for hypertension, obesity, polycystic ovary syndrome, abnormal uterine bleeding, multinodular thyroid gland, and vitamin D deficiency. Seven months before presentation, a chest radiograph (CXR) was obtained to evaluate unintended weight loss, and showed a 3 cm spiculated mass in the left lower lobe concerning for a primary lung malignancy. Follow-up computed tomography (CT) suggested that the left lower lobe mass corresponded to rounded atelectasis; however, at 6 month follow-up, low-dose chest CT scan revealed a 2.1 × 1.2 cm nodule within the central portion of the left lower lobe, with pleural thickening, and arising from or extending into the left lower lobe bronchus. The patient had no recent history of appetite change, exertional dyspnea, chronic cough, wheeze, fever, or other chest complaints. Her examination showed normal vital signs, oxygen saturation of 98% while inspiring room air, and an entirely normal lung and general physical examination, except for diminished breath sounds at the left base with no wheeze. An endobronchial ultrasound (EBUS) with fine-needle aspiration (FNA) and endobronchial biopsy was performed.

Pancreatic Cytology

The diagnostic approach to pancreaticobiliary disease requires a multidisciplinary team in which the cytopathologist plays a crucial role. Fine-needle aspiration, obtained by endoscopic ultrasound, is the diagnostic test of choice for pancreatic lesions. Preoperative clinical management depends on many factors, many of which rely on accurate cytologic assessment. Pancreaticobiliary cytology is wrought with diagnostic pitfalls. Clinical history, imaging studies, cytology samples, and ancillary tests, including immunohistochemistry, biochemical analysis, and genetic sequencing, are integral to forming a complete diagnosis and guiding optimal patient management. This article reviews clinical aspects and the diagnostic work-up of commonly encountered diagnostic entities within the field of pancreatic cytology.

Feasibility and safety of microforceps biopsy in the diagnosis of pancreatic cysts

BACKGROUND AND AIMS

The tissue acquisition and diagnostic yield of cyst fluid cytology is low-to-moderate and rarely provides a specific diagnosis. The aim of this study was to compare the tissue acquisition and diagnostic tissue yield of microforceps biopsy (MFB) with cyst fluid cytology.

METHODS

In this multicenter study, data of 42 patients who had cysts both aspirated by EUS-guided FNA (EUS-FNA) and biopsy specimens were then obtained with an MFB device, were collected. Cytology analysis of cyst fluid and histologic analysis of biopsy specimens were done. Acquisition yield was defined as percentage of patients with tissue present in the aspirate or biopsy. Diagnostic tissue yield was evaluated at 3 levels: the ability of differentiation between mucinous and/or nonmucinous cysts, detection of high risk for malignancy, and specific cyst type diagnosis.

RESULTS

The mean patient age was 69 years. Sixteen pancreatic cysts (38.1%) were located in the head, 17 (40.5%) in the body, and 9 (21.4%) in the tail. The mean cyst size was 28.2 mm (12-60 mm); 25 of 42 (60%) were septated. The EUS-FNA tissue (fluid) acquisition yield was 88.1% (37/42). The MFB tissue acquisition yield was 90.4% (38/42). The diagnostic cytology yield to differentiate between mucinous and/or nonmucinous cysts was 47.6% (20/42), and the MFB histologic yield to differentiate between mucinous and/or nonmucinous cysts was 61.9% (26/42) (P = .188). The percentage of cysts at high risk for malignancy by cytology was 54.7% (23/42), and MFB was 71.5% (30/42) (P = .113). However, the ability of MFB to provide a specific cyst type diagnosis was 35.7% (15/42), and that for cytology was 4.8% (2/42) (P = .001). Surgical histology was concordant with that of MFB in 6 of 7 patients (85%), and with that of cytology in 1 of 7 patients (15%).

CONCLUSION

The cyst tissue acquisition yield for MFBs was 90%. Although cytology of cyst fluid and MFB were comparable in distinguishing mucinous and nonmucinous cysts and detecting cysts at high risk for malignancy, MFB was far superior to cytology for providing a specific cyst diagnosis.

Moray micro forceps biopsy improves the diagnosis of specific pancreatic cysts

BACKGROUND

Making a specific diagnosis of pancreatic cysts preoperatively is difficult. The new disposable Moray micro forceps biopsy (MFB) device allows tissue sampling from the pancreatic cyst wall/septum and aims to improve diagnosis. This study compares the diagnostic performance of the MFB with the current conventional analysis of pancreatic cyst fluid (PCF).

METHODS

A total of 48 patients sampled with MFB were identified. Cysts were classified as mucinous on PCF based on extracellular mucin/mucinous epithelium, carcinoembryonic antigen (CEA) levels ≥192 ng/mL, or KRAS/GNAS mutation. A diagnosis of intraductal papillary mucinous neoplasm was supported by GNAS mutation; a diagnosis of serous cystadenoma was supported by Von Hippel-Lindau tumor suppressor (VHL) mutation. A diagnosis of mucinous cystic neoplasm required the presence of subepithelial ovarian-type stroma. A high-risk cyst was defined as a mucinous cyst with high-grade dysplasia or an adenocarcinoma. Comparisons in diagnostic performance between PCF and MFB were made.

RESULTS

The mean age of the patients was 69.6 years (range, 27-90 years); 25 of 48 patients (52.1%) were female. Cysts were in the pancreatic head (13 patients), neck (2 patients), body (20 patients), and tail (13 patients), averaging 3.1 cm (range, 1.2-6.0 cm). There was concordance with mucinous versus nonmucinous classification (60.4% for PCF vs 58.3% for MFB; P = .949). Three high-risk cysts were detected by PCF and 2 were detected by MFB (P = .670). However, MFB diagnosed significantly more specific cysts compared with PCF (50.0% for MFB vs 18.8% for PCF; P<.001).

CONCLUSIONS

PCF analysis and MFB have comparable performance in distinguishing between mucinous and nonmucinous cysts and for detecting high-risk cysts. However, MFB was found to be superior for diagnosing specific cyst subtypes, thus adding significant value to preoperative patient management. Cancer Cytopathol 2018;126:414-20. © 2018 American Cancer Society.

Inspissated cyst fluid in endoscopic ultrasound-guided fine needle aspiration of pancreatic cysts

BACKGROUND

Inspissated cyst fluid may be identified on pancreatic cyst aspiration cytology. We report on the cytomorphologic characteristics of inspissated cyst fluid on EUS-FNA of pancreatic cysts and correlate this finding with histopathology or multimodal (cytology, cyst fluid analysis, molecular pathology, imaging) classification of cyst type.

METHODS

The department archives were searched for pancreatic cyst fine-needle aspiration biopsies that contained dessicated, crystalline or inspissated material on cytologic preparations.

RESULTS

Twenty-eight cases of pancreatic cysts containing inspissated material were identified. The cytomorphology of the inspissated material ranged from fibrillary fan-like structure (54%), ball-like structures (57%), and granular material (43%). When present, the fibrillary inspissated material was associated with neoplastic mucinous cysts in 11/15 (73%) cases, but was also seen in 2 pseudocysts, 1 serous cystadenoma, and 1 cyst of uncertain type (suggestive of mucinous cyst on EUS). The presence of fibrillary inspissated cyst material on cytology had a positive predictive value of 79% and a specificity of 63% for a neoplastic mucinous cyst.

CONCLUSION

Although not highly specific, the presence of inspissated cyst fluid with fibrillary architecture should be recognized by cytopathologists and interpreted as at least "atypical" given the potential association with neoplastic mucinous cysts of the pancreas.

Fine-Needle Aspiration Biopsy of Palpable Breast Masses: Patterns of Clinical Use and Patient Experience

BACKGROUND

Timeliness is an important and recognized measure of health care quality. Multiple health organizations worldwide have published timeliness targets for breast cancer care. We performed the first comparison of patient wait times and utilization patterns for palpable breast mass diagnosis and treatment with regard to biopsy method.

PATIENTS AND METHODS

Palpable breast masses in women biopsied via a fine-needle aspiration (FNA) or core biopsy at 2 affiliated academic medical centers in 2009 were analyzed if subsequently treated with excision or neoadjuvant therapy. Patient demographics, mass size and radiologic features, pathology diagnoses, and wait times to diagnosis and treatment were recorded.

RESULTS

Patients diagnosed by FNA biopsy received their biopsy diagnosis more than 8 days sooner than those diagnosed by core biopsy. Most FNA biopsies occurred the same day the patient clinically presented. Time to treatment did not differ significantly between groups. Both biopsy methods demonstrated comparable diagnostic accuracy. Breast masses diagnosed by FNA biopsy had Breast Imaging Reporting and Data System (BI-RADS) scores ranging from 1 through 5, whereas nearly all core biopsy cases had a BI-RADS score of 4 or greater. All patient groups were demographically comparable and presented with similar breast mass sizes.

CONCLUSIONS

Wait times for breast biopsies were significantly shorter for patients diagnosed by FNA compared with core biopsy. FNA biopsy was often used to evaluate breast masses of low clinical suspicion. In light of health care goals for practice improvement and cost containment, breast FNA biopsy may be an underused resource.

Post-fine-needle aspiration biopsy communication and the integrated and standardized cytopathology report

Communication between cytopathologists and patients and their care team is a critical component of accurate and timely patient management. The most important single means of communication for the cytopathologist is through the cytopathology report. Implementation of standardized terminology schemes and structured, templated reporting facilitates the ability of the cytopathologist to provide a comprehensive and integrated report. Cytopathology has been among the pathology subspecialties that have led the way in developing standardized reporting, beginning with the 1954 Papanicolaou classification scheme for cervical-vaginal cytology and continuing through the Bethesda systems for gynecological cytology and several nongynecological cytology systems. The effective reporting of cytopathology necessarily becomes more complex as it addresses increasingly sophisticated management options, requiring the integration of information from a broader range of sources. In addition to the complexity of information inputs, a wider spectrum of consumers of these reports is emerging, from patients themselves to primary care providers to subspecialized disease management experts. Both these factors require that the reporting cytopathologist provide the integration and interpretation necessary to translate diverse forms of information into meaningful and actionable reports that will inform the care team while enabling the patient to meaningfully participate in his or her own care. To achieve such broad and focused communications will require first the development of standardized and integrated reports and ultimately the involvement of cytopathologists in the development of the clinical informatics needed to treat all these items of information as structured data elements with flexible reporting operators to address the full range of patient and patient care needs. Cancer Cytopathol 2017;125(6 suppl):486-93. © 2017 American Cancer Society.

Cytologic characteristics of circulating epithelioid cells in pancreatic disease

BACKGROUND

Circulating epithelioid cells (CECs), also known as circulating tumor, circulating cancer, circulating epithelial, or circulating nonhematologic cells, are a prognostic factor in various malignancies that can be isolated via various protocols. In the current study, the authors analyzed the cytomorphologic characteristics of CECs isolated by size in a cohort of patients with benign and malignant pancreatic diseases to determine whether cytomorphological features could predict CEC origin.

METHODS

Blood samples were collected from 9 healthy controls and 171 patients with pancreatic disease who were presenting for surgical evaluation before treatment. Blood was processed with the ScreenCell size-based filtration device. Evaluable CECs were analyzed in a blinded fashion for cytomorphologic characteristics, including cellularity; nucleoli; nuclear size, irregularity, variability, and hyperchromasia; and nuclear-to-cytoplasmic ratio. Statistical differences between variables were analyzed via the Fisher exact test.

RESULTS

No CECs were identified among the 9 normal healthy controls. Of the 115 patients with CECs (positive or suspicious for), 25 had nonmalignant disease and 90 had malignancy. There were no significant differences in any of the cytologic criteria noted between groups divided by benign versus malignant, neoplastic versus nonneoplastic, or pancreatic ductal adenocarcinoma versus neuroendocrine tumor.

CONCLUSIONS

CECs were observed in patients with malignant and nonmalignant pancreatic disease, but not in healthy controls. There were no morphologic differences observed between cells from different pancreatic diseases, suggesting that numerous conditions may be associated with CECs in the circulation and that care must be taken not to overinterpret cells identified by cytomorphology as indicative of circulating tumor cells of pancreatic cancer. Additional studies are required to determine the origin and clinical significance of these cells. Cancer Cytopathol 2017;125:332-340. © 2017 American Cancer Society.

Value of adding GNAS testing to pancreatic cyst fluid KRAS and carcinoembryonic antigen analysis for the diagnosis of intraductal papillary mucinous neoplasms

BACKGROUND AND AIM

Molecular analysis of pancreatic cyst fluid (PCF) has been proposed as a novel method for differentiating pancreatic cystic lesions (PCL). The present study aimed to investigate the value of GNAS testing when added to KRAS and carcinoembryonic antigen (CEA) testing of PCF for the diagnosis of intraductal papillary mucinous neoplasms (IPMN).

METHODS

Prospectively collected endoscopic ultrasonography fine-needle aspiration (EUS-FNA) data were analyzed retrospectively for GNAS and KRAS mutations and CEA results. IPMN were histologically confirmed or supported by imaging and EUS-FNA findings (KRAS, CEA, cytology). Performance characteristics of GNAS added to KRAS and CEA for the diagnosis of IPMN were calculated.

RESULTS

The study population consisted of 197 patients with cyst fluid test results. Cysts were histologically classified in 33 patients and by clinical criteria in 164 patients. The IPMN group included 108 patients and the non-IPMN group included 89 patients. GNAS was positive in 51 patients (47.2%) with IPMN. Forty-two of these patients (82.3%) also had a KRAS mutation. Adding GNAS to KRAS increased the diagnostic accuracy from 76.6% to 79.1% (P > 0.05). Adding GNAS to CEA increased the diagnostic accuracy from 66.4% to 80.7 % (P < 0.05), but did not achieve a diagnostic superiority to KRAS testing alone (80.7% vs 76.6%, P > 0.05). The diagnostic accuracy of the triple combination was significantly better than all single tests (P < 0.05).

CONCLUSION

GNAS mutation is a highly specific test for IPMN. When GNAS testing is added to CEA and KRAS, a significantly greater overall accuracy (86.2%) is achieved.

Preoperative characteristics and cytological features of 136 histologically confirmed pancreatic mucinous cystic neoplasms

BACKGROUND

Mucinous cystic neoplasms (MCNs) of the pancreas present a management conundrum. The majority are benign but all are resected due to their malignant potential. Recent studies have recommended nonsurgical management. In the current study, the authors analyzed the preoperative imaging, cytology, and cyst fluid characteristics of 136 histologically confirmed MCNs to assess predictors of a high-risk (HR) cyst for surgical triage.

METHODS

MCNs resected at the Massachusetts General Hospital between 1990 and 2014 formed the study cohort. Patient demographics, cyst size, and mural nodules (MNs) by endoscopic ultrasound, cytology, and cyst fluid carcinoembryonic antigen and amylase levels were correlated with histological grade. A HR cyst was defined as high-grade dysplasia or invasive carcinoma on histology. Performance characteristics were assessed for each parameter, with a cyst size ≥3 cm or a MN on imaging and malignant cytology considered to be "true-positive" results for predicting malignancy.

RESULTS

Only 15 of the 136 cysts had HR histology (11%). On average, patients with HR cysts were older than those with low-risk cysts (55 years vs 49 years, respectively). High-grade cytology was the most accurate predictor of malignancy (95%) followed by MN and cyst size together (88%) and MN alone (83%). The average carcinoembryonic antigen level (in ng/mL) increased with the grade of dysplasia but the ranges overlapped between low risk and HR cysts.

CONCLUSIONS

To the authors' knowledge, the current study is the largest series to date analyzing the cytological features of histologically confirmed MCN. Cytology is insensitive but very specific for detecting a HR MCN and outperformed imaging for the detection of HR MCN. Endoscopic ultrasound-guided fine-needle aspiration and cytology should be performed on any clinically suspected MCN that is being considered for conservative management. Cancer Cytopathol 2017;125:169-177. © 2016 American Cancer Society.

Next-generation sequencing adds value to the preoperative diagnosis of pancreatic cysts

BACKGROUND

The diagnosis of a pancreatic cyst as mucinous or high-risk dictates the need for follow-up or surgery. Molecular analysis of aspirated pancreatic cyst fluid (PCF) can provide valuable information not obtained by carcinoembryonic antigen (CEA) analysis or cytology.

METHODS

All patients who underwent molecular analysis of PCF between March 2013 and June 2015 were reviewed, including pathology, imaging, and follow-up. Molecular testing was performed using a patented, anchored multiplex polymerase chain reaction next-generation sequencing (NGS) platform, which sequenced numerous hotspots in 39 genes linked with malignancy. Performance of NGS and cytology was calculated using final outcome, as determined by clinicopathologic follow-up.

RESULTS

The study cohort included 113 PCFs from 105 patients. In total, 119 variants were detected in 67 PCFs (59%). Variants were more common in intraductal papillary mucinous neoplasms (IPMNs)/cancer than in nonmucinous cysts (P < .005). The inclusion of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS)/guanine nucleotide-binding protein (GNAS) variants improved the classification of IPMNs as mucinous from 50% by microscopy to 100%. Seventy-five percent of cancers had high-grade atypia versus 0% of IPMNs and nonmucinous cysts (P < .002). Variants in tumor protein 53 (TP53), SMAD family member 4 (SMAD4), cyclin-dependent kinase inhibitor 2A (CDKN2A), and notch1 (NOTCH1) were detected only in malignant cysts. Cytology was similarly specific (100%) for detecting malignant cysts but was more sensitive than the identification of late mutations by NGS (75% vs 46%).

CONCLUSIONS

The detection of KRAS/GNAS variants improves the identification of mucinous neoplasms. Variants in TP53, SMAD4, CDKN2A, and NOTCH1 support the diagnosis of a high-risk cyst requiring surgery or additional sampling. Although molecular analysis is not a replacement for cytopathology, it does provide valuable information for accurate preoperative diagnosis, helping to classify mucinous neoplasms and high-risk cysts that require surgical resection. Cancer Cytopathol 2017;125:41-47. © 2016 American Cancer Society.

The value of KRAS mutation testing with CEA for the diagnosis of pancreatic mucinous cysts

BACKGROUND AND AIMS

Pancreatic cyst fluid (PCF) CEA has been shown to be the most accurate preoperative test for detection of cystic mucinous neoplasms (CMNs). This study aimed to assess the added value of PCF KRAS mutational analysis to CEA for diagnosis of CMNs.

PATIENTS AND METHODS

This is a retrospective study of prospectively collected endoscopic ultrasonography (EUS) fine-needle aspiration (FNA) data. KRAS mutation was determined by direct sequencing or equivalent methods. Cysts were classified histologically (surgical cohort) or by clinical (EUS or FNA) findings (clinical cohort). Performance characteristics of KRAS, CEA and their combination for detection of a cystic mucinous neoplasm (CMN) and malignancy were calculated.

RESULTS

The study cohort consisted of 943 patients: 147 in the surgical cohort and 796 in the clinical cohort. Overall, KRAS and CEA each had high specificity (100 % and 93.2 %), but low sensitivity (48.3 % and 56.3 %) for the diagnosis of a CMN. The positivity of KRAS or CEA increased the diagnostic accuracy (80.8 %) and AUC (0.84) significantly compared to KRAS (65.3 % and 0.74) or CEA (65.8 % and 0.74) alone, but only in the clinical cohort (P < 0.0001 for both). KRAS mutation was significantly more frequent in malignant CMNs compared to histologically confirmed non-malignant CMNs (73 % vs. 37 %, P = 0.001). The negative predictive value of KRAS mutation was 77.6 % in differentiating non-malignant cysts.

CONCLUSIONS

The detection of a KRAS mutation in PCF is a highly specific test for mucinous cysts. It outperforms CEA for sensitivity in mucinous cyst diagnosis, but the data does not support its routine use.

Automated Extraction of Formalin-Fixed, Paraffin-Embedded Tissue for High-Risk Human Papillomavirus Testing of Head and Neck Squamous Cell Carcinomas Using the Roche Cobas 4800 System

CONTEXT

-Testing for high-risk human papillomavirus (HR-HPV) in head and neck squamous cell carcinomas (HNSCCs) is important for both prognostication and clinical management. Several testing platforms are available for HR-HPV; however, effective alternative automated approaches are needed.

OBJECTIVE

-To assess the performance of the automated Roche cobas 4800 HPV real-time polymerase chain reaction-based system on formalin-fixed, paraffin-embedded HNSCC specimens and compare results with standard methods of in situ hybridization (ISH) and p16 immunohistochemistry.

DESIGN

-Formalin-fixed, paraffin-embedded samples of HNSCC were collected from archival specimens in the Department of Pathology, Massachusetts General Hospital (Boston), and prepared using the automated system by deparaffinization and dehydration followed by tissue lysis. Samples were integrated into routine cervical cytology testing runs by cobas. Corresponding formalin-fixed, paraffin-embedded samples were evaluated for HR-HPV by ISH and p16 by immunohistochemistry. Discrepant cases were adjudicated by polymerase chain reaction.

RESULTS

-Sixty-two HNSCC samples were analyzed using the automated cobas system, ISH, and immunohistochemistry. Fifty-two percent (n = 32 of 62) of formalin-fixed, paraffin-embedded tumors were positive for HR-HPV by cobas. Eighty-eight percent (n = 28 of 32) of cases were the HPV 16 subtype and 12% (n = 4 of 32) were other HR-HPV subtypes. Corresponding testing with ISH was concordant in 92% (n = 57 of 62) of cases. Compared with the adjudication polymerase chain reaction standard, there were 3 false-positive cases by cobas.

CONCLUSIONS

-Concordance in HNSCC HR-HPV status between cobas and ISH was more than 90%. The cobas demonstrated a sensitivity of 100% and a specificity of 91% for detection of HR-HPV. Advantages favoring cobas include its automation, cost efficiency, objective results, and ease of performance.

Impact of next-generation sequencing on the clinical diagnosis of pancreatic cysts

BACKGROUND AND AIMS

The value of next-generation sequencing (NGS) of pancreatic cyst fluid relative to the clinical and imaging impression has not been well-studied. The aim of this study was to assess the impact of NGS on the clinical diagnosis from imaging and carcinoembryonic antigen (CEA) and thus the management of pancreatic cysts.

METHODS

Ninety-two pancreatic cyst fluids from 86 patients were analyzed by cytology, CEA, and targeted NGS. Cysts were classified by imaging as nonmucinous, mucinous, or not specified. NGS results were compared with the imaging impression stratified by CEA and cytology.

RESULTS

NGS impacted the clinical diagnosis by defining a cyst as mucinous in 48% of cysts without elevated CEA levels. The VHL gene in 2 intraductal papillary mucinous neoplasms (IPMNs) supported a serous cystadenoma. Twenty percent of cysts that were nonmucinous by imaging were mucinous by NGS. Of the 14 not-specific cysts, CEA levels were not elevated in 12 (86%), and NGS established a mucinous etiology in 3 (25%). A KRAS or GNAS mutation supported an IPMN with nonmucinous CEA in 71%. A KRAS mutation reclassified 19% of nonneoplastic cysts with nonmucinous CEA as mucinous. Seven cyst fluids (8%) had either a TP53 mutation or loss of CDKN2A or SMAD4 in addition to KRAS and/or GNAS mutations; 5 of 7 (71%) were clinically malignant, and high-grade cytology was detected in all 5. Overall, CEA was more specific for a mucinous etiology (100%), but NGS was more sensitive (86% vs 57%).

CONCLUSIONS

NGS of pancreatic cyst fluid impacts clinical diagnosis and patient management by defining, supporting, or changing the clinical diagnosis based on imaging and CEA. NGS was most valuable in identifying mucinous cysts with nonmucinous CEA. An added benefit is the potential to detect mutations late in the progression to malignancy that may increase the risk classification of the cyst based on imaging and cytology.

Circulating Epithelial Cells in Patients with Pancreatic Lesions: Clinical and Pathologic Findings

BACKGROUND

Circulating epithelial cell (CEC) isolation has provided diagnostic and prognostic information for a variety of cancers, previously supporting their identity as circulating tumor cells in the literature. However, we report CEC findings in patients with benign, premalignant, and malignant pancreatic lesions using a size-selective filtration device.

STUDY DESIGN

Peripheral blood samples were drawn from patients found to have pancreatic lesions on preoperative imaging at a surgical clinic. Blood was filtered using ScreenCell devices, which were evaluated microscopically by a pancreatic cytopathologist. Pathologic data and clinical outcomes of these patients were obtained from medical records during a 1-year follow-up period.

RESULTS

Nine healthy volunteers formed the control group and were found to be negative for CECs. There were 179 patients with pancreatic lesions that formed the study cohort. Circulating epithelial cells were morphologically similar in patients with a variety of pancreatic lesions. Specifically, CECs were identified in 51 of 105 pancreatic ductal adenocarcinomas (49%), 7 of 11 neuroendocrine tumors (64%), 13 of 21 intraductal papillary mucinous neoplasms (62%), and 6 of 13 patients with chronic pancreatitis. Rates of CEC identification were similar in patients with benign, premalignant, and malignant lesions (p = 0.41). In addition, CEC findings in pancreatic ductal adenocarcinoma patients were not associated with poor prognosis.

CONCLUSIONS

Although CECs were not identified in healthy volunteers, they were identified in patients with benign, premalignant, and malignant pancreatic lesions. The presence of CECs in patients presenting with pancreatic lesions is neither diagnostic of malignancy nor prognostic for patients with pancreatic ductal adenocarcinoma.