Cytology Specimen Management, Triage and Standardized Reporting of Fine Needle Aspiration Biopsies of the Pancreas

Imaging of pancreatic serous cystadenoma and common imitators

Pancreatic cystic neoplasms are lesions comprised of cystic components that show different biological behaviors, epidemiology, clinical manifestations, imaging features, and malignant potential and management. Benign cystic neoplasms include serous cystic neoplasms (SCAs). Other pancreatic cystic lesions have malignant potential, such as intraductal papillary mucinous neoplasms and mucinous cystic neoplasms. SCAs can be divided into microcystic (classic appearance), honeycomb, oligocystic/macrocystic, and solid patterns based on imaging appearance. They are usually solitary but may be multiple in von Hippel-Lindau disease, which may depict disseminated involvement. The variable appearances of SCAs can mimic other types of pancreatic cystic lesions, and cross-sectional imaging plays an important role in their differential diagnosis. Endoscopic ultrasonography has helped in improving diagnostic accuracy of pancreatic cystic lesions by guiding tissue sampling (biopsy) or cyst fluid analysis. Immunohistochemistry and newer techniques such as radiomics have shown improved performance for preoperatively discriminating SCAs and their mimickers.

"Evolving Trends in Pancreatic Cystic Tumors: A 3-Decade Single-Center Experience With 1290 Resections"

OBJECTIVE

The aim of this study was to describe our institutional experience with resected cystic tumors of the pancreas with emphasis on changes in clinical presentation and accuracy of preoperative diagnosis.

SUMMARY BACKGROUND DATA

Incidental discovery of pancreatic cystic lesions has increased and has led to a rise in pancreatic resections. It is important to analyze surgical outcomes from these procedures, and the prevalence of malignancy, pre-malignancy and resections for purely benign lesions, some of which may be unintended.

METHODS

Retrospective review of a prospective database spanning 3 decades. Presence of symptoms, incidental discovery, diagnostic studies, type of surgery, postoperative outcomes, and concordance between presumptive diagnosis and final histopathology were recorded.

RESULTS

A total of 1290 patients were identified, 62% female with mean age of 60 years. Fifty-seven percent of tumors were incidentally discovered. Ninety-day operative mortality was 0.9% and major morbidity 14.4%. There were 23 different diagnosis, but IPMN, MCN, and serous cystadenoma comprised 80% of cases. Concordance between preoperative and final histopathological diagnosis increased by decade from 45%, to 68%, and is presently 80%, rising in parallel with the use of endoscopic ultrasound, cytology, and molecular analysis. The addition of molecular analysis improved accuracy to 91%. Of misdiagnosed cases, half were purely benign and taken to surgery with the presumption of malignancy or premalignancy. The majority of these were serous cystadenomas.

CONCLUSIONS

Indications and diagnostic work-up of cystic tumors of the pancreas have changed over time. Surgical resection can be performed with very low mortality and acceptable morbidity and diagnostic accuracy is presently 80%. About 10% of patients are still undergoing surgery for purely benign lesions that were presumed to be malignant or premalignant. Further refinements in diagnostic tests are required to improve accuracy.

Role of fluorescence confocal microscopy for rapid evaluation of EUS fine-needle biopsy sampling in pancreatic solid lesions

BACKGROUND AND AIMS

EUS fine-needle biopsy (EUS-FNB) sampling is the standard procedure for diagnosis of pancreatic lesions. Fluorescence confocal microscopy (FCM) allows imaging of tissues in the fresh state, requiring minimal preparation without damage or loss of tissue. Until now, no data exist on FCM in the field of microhistologic specimens. We aimed to assess the diagnostic performance of FCM in predicting histologic adequacy of EUS-FNB samples in pancreatic solid lesions and to assess the agreement between FCM evaluation and final histology.

METHODS

In this single-center prospective study on consecutive patients with pancreatic lesions receiving EUS-FNB, the obtained samples have been evaluated at FCM and classified as "inadequate" or "adequate" (benign, suspicious, or malignant). The kappa test was used to quantify agreement. The diagnostic accuracy of FCM was assessed. A P < .05 was considered to be statistically significant.

RESULTS

From April 2020 to September 2020, 81 patients were enrolled. In all cases FCM showed the macro image of the sample and created a digital image. Of the samples, 92.6% was defined as adequate at the FCM evaluation and confirmed at histopathology. Histologic diagnoses were 8% benign, 17.3% atypical/suspicious, and 74.7% malignant with satisfactory agreement with the FCM evaluation (Cohen's κ coefficient, .95; 95% confidence interval [CI], .89-1.01; P = .001). The sensitivity of the FCM evaluation was 100% (95% CI, 95%-100%), specificity 66.7% (95% CI, 22.3%-95.7%), accuracy 97% (95% CI, 90.7%-99.7%), positive predictive value 97% (95% CI, 91.8%-99%), and negative predictive value 100%.

CONCLUSIONS

FCM represents a new technique successfully applicable to microhistologic specimens. It provides fast information about sample adequacy in small specimens with good agreement in the final histology.

It is necessary to exam bottom and top slide smears of EUS-FNA for pancreatic cancer

BACKGROUND

Despite many reports on the diagnostic yield of cytology from endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), inter-slide differences are unknown. This prospective study aimed to compare diagnostic yield and cellular characteristics of bottom slides (BS) and top slides (TS) from EUS-FNA cytology performed without an on-site cytopathologist.

METHODS

In patients with suspected pancreatic cancer on previous imaging explorations, a single endoscopist performed EUS-FNA and obtained 2 sets of cytology slide (8 BS and 8 TS), 1 cellblock slide, and 1 biopsy slide. Both slide sets were randomly assigned. A cytopathologist with more than 10 years of expertise in pancreatic cytopathology blindly inspected and compared two slide sets.

RESULTS

In total, 73 specimens [42 head (57.5%), 16 body (21.9%), and 15 tail (20.5%)] were acquired for final analysis. Seventy-one cases were finally diagnosed with pancreatic cancer. The sensitivity and specificity of BS were 80.3% and 100.0%; and of TS 78.9% and 100.0%, respectively. In analyzing inter-slide difference, 66 cases (90.4%) showed consistent results between BS and TS. However, seven (9.6%) were positive only in one slide sets (4 BS and 3 TS). The proportions of specimens more than moderate and high cellularity were 75.3% and 60.3% in both slide sets (P> 0.99), and the proportion of artifact-free sets were 50.7%, and 52.1% for the BS and TS, respectively (P= 0.869).

CONCLUSIONS

Although BS and TS exhibited highly consistent diagnostic yields in cytologic smears from EUS-FNA, the proportion of inter-slide discordance is clinically considerable. Both slide sets need to be examined if there is no on-site cytopathologist.

Rationale and feasibility of mucin expression profiling by qRT-PCR as diagnostic biomarkers in cytology specimens of pancreatic cancer

BACKGROUND

Aberrantly expressed mucin glycoproteins (MUC) play important roles in pancreatic ductal adenocarcinoma (PDAC), yet their use as a diagnostic aid in fine-needle aspiration biopsy (FNAB) is poorly documented. The aim of this study was to investigate the rationale and feasibility of mucin (MUC1, MUC2, MUC3, MUC4, MUC5AC, and MUC6) expression profiling by RT-PCR for diagnostic applications in cytology.

METHODS

Mucin expression was examined by RT-PCR and immunohistochemistry in specimens resected from patients with pancreatic (n = 101), ampullary (n = 23), and common bile duct (n = 10) cancers and 33 with chronic pancreatitis. Furthermore, mucin profiling by RT-PCR was prospectively compared in surgical and biopsy specimens of 40 patients with pancreatic solid tumours qualified for FNAB prior to surgery.

RESULTS

A logistic regression model to distinguish PDAC from chronic pancreatitis using RT-PCR profiling included MUC3, MUC5AC, and MUC6. The same set of mucins differentiated ampullary and bile duct cancers from chronic pancreatitis. AUCs for the ROC curves derived from the two models were 0.95 (95%CI 0.87-0.99) and 0.92 (95%CI 0.81-0.98), respectively. The corresponding positive likelihood ratios were 6.02 and 5.97, while the negative likelihood ratios were 0.10 and 0.12. AUCs of ROC curves obtained by RT-PCR and immunohistochemistry demonstrated that both analytical methods were comparable. Surgical and cytological samples showed significantly correlated values of ΔCt for individual mucins with the overall Pearson's correlation coefficient r = 0.841 (P = 0.001).

CONCLUSIONS

Mucin expression profiling of pancreatic cancer with RT-PCR is feasible and may be a valuable help in discriminating malignant lesions from chronic pancreatitis in FNAB cytology.

Pancreatic Cytopathology

Pancreatic cytopathology, particularly through the use of endoscopic ultrasound-guided fine-needle aspiration (FNA), has excellent specificity and sensitivity for the diagnosis of pancreatic lesions. Such diagnoses can help guide preoperative management of patients, provide prognostic information, and confirm diagnoses in patients who are not surgical candidates. Furthermore, FNA can be used to obtain cyst fluid for ancillary tests that can improve the diagnosis of cystic lesions. In this article, we describe the cytomorphological features and differential diagnoses of the most commonly encountered pancreatic lesions on FNA.

Variations in cancer centers' use of cytology for the diagnosis of unresectable pancreatic cancer in the National Cancer Data Base

BACKGROUND

Cytology is an accurate, safe, cost-effective, and guideline-recommended method for pancreatic cancer diagnosis, particularly for unresectable disease. However, to the authors' knowledge, the frequency and determinants of its use have not been described to date. The current study examined patterns of cytological diagnosis among patients with unresectable pancreatic cancer by treatment facility type and by patient characteristics.

METHODS

The prevalence of definitive cytological diagnosis (cytology only, without confirmatory histology) versus histological diagnosis (with or without accompanying cytology) was examined in National Cancer Data Base records of 13,657 patients diagnosed with unresectable (American Joint Committee on Cancer stages III and IV) pancreatic cancer in 2011 and 2012 who did not undergo surgical treatment (mode of diagnosis could not be ascertained for surgical patients). Associations between definitive cytological diagnosis and patient and facility characteristics were assessed using multivariable marginal logistic regression models and expressed as odds ratios (OR) and 95% confidence intervals (95% CIs).

RESULTS

Overall, 26.8% of unresectable pancreatic cancer cases were definitively diagnosed with cytology. The prevalence of cytological diagnosis ranged from 16.5% in community cancer programs and 22.6% in comprehensive community cancer programs to 31.3% in academic/teaching/research cancer programs and 43.2% in National Cancer Institute-designated cancer programs (P<.001). Compared with patients diagnosed in National Cancer Institute-designated cancer programs, those from community cancer programs (OR, 0.29; 95% CI, 0.20-0.42), comprehensive community cancer programs (OR, 0.42; 95% CI, 0.31-0.59), and academic/teaching/research cancer programs (OR, 0.60; 95% CI, 0.43-0.84) had lower odds of being diagnosed with cytology.

CONCLUSIONS

Greater than 25% of unresectable pancreatic cancers were diagnosed definitively with cytology, with wide variation in its use by facility type, suggesting opportunities for quality improvement interventions that increase the use of cytology. Cancer Cytopathol 2016;124:791-800. © 2016 American Cancer Society.