Rapid on-site evaluation improves diagnostic performance of fine-needle aspiration cytology for salivary lesions: Comparison of data from two cancer centers in southern China

OBJECTIVES

To evaluate the diagnostic performance of Milan system for reporting salivary gland cytopathology (MSRSGC) in two southern China tertiary cancer centers and investigate the impact of rapid on-site evaluation (ROSE) on FNAC performance.

MATERIALS AND METHODS

Five hundred and forty-nine patients who underwent FNAC for salivary lesions with surgical follow-up from two centers were enrolled in this retrospective cohort study. All slides were recategorized using MSRSGC after consensus on diagnostic criteria for each category. The diagnostic performance of FNAC for salivary lesions was evaluated and compared and the impact of ROSE on FNAC performance was analyzed.

RESULTS

The distribution of cases per category based on the MSRSGC criteria in the whole series was as followed: ND 49 (8.9%), NN 76 (14.4%), BN 262 (47.7%), AUS 20 (3.6%), SUMP 43 (7.8%), SM 21 (3.8%), M 78 (14.2%). The SUMC series had significantly more ND distributions than JXCH did (16.2% vs. 0, p = .000). Risk of malignancy for each category in the total series was as followed: 42.9% for ND, 9.2% for NN, 3.8% for BN, 30.0% for AUS, 23.3% for SUMP, 81.0% for SM, and 94.9% for M. When ND and AUS/SUMP were excluded, the sensitivity, specificity, PPV, NPV, and accuracy were 84.0%, 97.1%, 89.9%, 95.1%, and 94.0%, respectively; sensitivity, specificity, PPV, NPV, and accuracy were comparable between the two centers.

CONCLUSIONS

FNAC using MSRSGC provides a good tool in preoperative evaluation for salivary lesions in southern China. ROSE improves its diagnostic performance by reducing the ratio of the ND category.

Thyroid poorly differentiated carcinoma metastatic to pancreas diagnosed by fine-needle aspiration and demonstrating a novel BRAF fusion

Differentiating pancreatic duct adenocarcinoma from metastasis can be challenging by morphology alone. Metastasis from a classic papillary thyroid carcinoma can present as a poorly differentiated carcinoma and mimic pancreatic ductal adenocarcinoma's morphology.

Fusion of old and new: Employing touch imprint slides for next generation sequencing in solid tumors

BACKGROUND

Cytomorphological evaluation of tissue touch imprints during rapid on-site evaluation or intraoperative pathology consultation has crucial value. However, literature on their utility for molecular testing is limited. In this study, we emphasize a further benefit of touch imprint slides and scrutinize our institutional experience on their use in molecular testing, specifically next generation sequencing (NGS).

MATERIALS AND METHODS

NGS-based reports (2019-2023) of Koç University Hospital were retrospectively analyzed and circumstances in which sequencing was conducted on touch imprint slides were retrieved (n = 18). Type/location of the biopsy, diagnosis, results, and quality metrics were recorded.

RESULTS

Touch imprints were addressed when they harbored more neoplastic cells compared with permanent biopsies, when suboptimal fixation mitigated deoxyribonucleic acid/ribonucleic acid (DNA/RNA) yield in resections or when the sample was obtained from bone and required decalcification. Diagnoses were diverse, namely non-small-cell lung cancer, gastric adenocarcinoma, glial tumor, Ewing sarcoma, and carcinoma of unknown primary. The percentage of tumor cells on slides stretched between 15% and 70%. Molecular findings ranged from KRAS mutations to TRIM1::NTRK2 and EWSR::FLI1 fusions. For five cases, sequencing did not yield any alteration, one study was not completed because it did not yield high-quality RNA.

CONCLUSION

Touch imprint slides provide a reliable alternative, especially when neoplastic cells are scarce in permanent biopsies or decalcification deters nucleic acid quality. Based on our experience, we suggest making touch imprints on a routine basis, especially for every bone biopsy. Once digitally scanned duplicates are made, original slides can be safely used for DNA-/RNA-based molecular studies.

Trichilemmal carcinoma metastatic to parotid gland: First report of fine needle aspiration cytology features

Trichilemmal carcinoma is a rare malignant cutaneous adnexal neoplasm arising from the outer root sheath of the hair follicle. Majority of cases occur on sun-exposed sites such as the face, scalp and neck, making them easily amenable to being biopsied and subjected to histological examination for definitive diagnosis. Thus, cytological features of trichilemmal carcinoma have not been described till date. Trichilemmal carcinoma is a low-grade malignancy, albeit with potential to metastasize to regional lymph nodes and distant sites. We report the case of trichilemmal carcinoma of scalp that metastasized to cervical lymph nodes and parotid gland and underwent fine-needle aspiration cytology (FNAC) from the parotid lesion. The aspirate showed tightly cohesive cell clusters with sharp borders. Tumour cells ranged from basaloid with scant cytoplasm to those with abundant cytoplasm. Nuclei were vesicular, with inconspicuous to prominent nuclei. Intercellular bridges, masses of keratin, and fragments of desmoplastic stroma were present, closely recapitulating histological features of trichilemmal carcinoma, which enabled diagnosis as metastasis. Cell block showed similar tumour fragments with evidence of differentiation towards outer root sheath. FNAC is the first-line investigation to obtain a tissue diagnosis of masses in the head and neck region. Although rarely encountered, the lack of knowledge of cytological features of trichilemmal carcinoma may hamper its FNAC diagnosis at metastatic sites. When intraparotid metastases occur, they may be mistaken as primary salivary gland carcinoma. Thus, awareness of the cytological features of this tumour must be raised among cytopathologists to enable accurate diagnosis and further management.

Updates in head and neck cytopathology: Insights from European Congress of Pathology Short Course

Cytological specimens play a pivotal role in head and neck nodule/mass work up and diagnoses. The specimens´ importance has grown with the onset of personalized medicine and the routine use of molecular markers in the diagnostic work up. The Updates in Head and Neck Cytopathology Short Course ran during the 35th European Congress of Pathology held in Dublin, Ireland, in 2023 and brought together experts in cytopathology, pathology, and related fields to share their expertise and experience in the field of head and neck cytopathology and its future directions. Topics such as a one-stop clinic, the Milan System for Reporting Salivary Gland Cytopathology, next generation sequencing, and human papilloma virus detection in the head and neck area were covered during the short course. These topics are briefly summarized in the present review.

AIns (insulin) type amyloidoma of the extremity diagnosed by fine-needle aspiration

Amyloid is an extracellular deposition of Congo red positive material which shows apple green birefringence under polarized light. A cytopathologist can uncommonly encounter such cases. Among the reported cases, a fine-needle aspiration (FNA) of amyloid is frequently misinterpreted as acellular nondiagnostic material. We report a case of amyloidoma of the right upper arm in a 68-year-old man with history of renal transplantation for diabetic nephropathy who presented with loss of appetite and weight loss. Physical exam showed a 7 cm hard nodular subcutaneous mass in the right upper arm. FNA yielded abundant acellular, irregular fragments of dense material, which was Congo red positive with apple green birefringence by polarized light, consistent with amyloid. Further subtyping of the amyloid by mass spectrometry, showed AIns (insulin)-type amyloid deposition. After further questioning, the patient admitted to injecting insulin at the same site for many years. Awareness of the cytological features is important for diagnosis. This is especially important when dealing with uncommon sites and without adequate clinical information.

World Health Organization reporting system for lung cytopathology-A brief correspondence

The WHO lung cytopathology reporting system has been published recently and is now a five-tier category system without any subcategorization. WHO reporting system also encourages the application of ancillary diagnostic tests like cell block preparation, immunocytochemistry, and rapid on-site evaluation for better categorization of specimens and further management. This correspondence aims to provide a brief outline of the lung reporting system. Lung cytopathology reporting system use standardized nomenclature and usage of the terminologies harmonizing with the WHO Blue Book, and table and flow diagram may be helpful for the readers.

Molecular testing in salivary gland cytopathology: A practical overview in conjunction with the Milan system

Recently, significant advances in the molecular characterization of salivary gland neoplasms have facilitated the classification and diagnosis of specific diagnostic entities. In the highly challenging diagnostic scenario of salivary malignancies, molecular testing is increasingly being adopted in routine practice to refine the cytological diagnosis of salivary lesions. Here, we reviewed the most recent evidence in the field of salivary glands molecular cytopathology.

Solid pseudopapillary neoplasm of pancreas with liver metastasis, diagnosed on fine needle aspiration cytology (FNAC)

Solid pseudopapillary neoplasm of the pancreas is a rare tumour with distinct clinicopathological features. The tumour most commonly occurs in younger women and has low malignant potential with an excellent overall prognosis.

Cutaneous balloon-cell melanoma metastases to the axillary lymph node: Exploring cytomorphologic features and differential diagnoses on fine needle aspiration biopsy

Balloon cell melanoma (BCM) is an exceptionally uncommon histological variant, making up <1% of all malignant melanomas. Diagnosing balloon cell melanoma on cytological specimens can be challenging due to its scarcity and its similarity to other medical conditions. A comprehensive clinical assessment and histological analysis, coupled with immunohistochemical staining, play a crucial role in distinguishing balloon cell melanoma from various benign and malignant skin conditions. The differential diagnoses encompass spitz nevus, balloon cell nevus, clear cell sarcoma of tendons and aponeuroses (melanoma of soft tissues), metastatic clear cell renal cell carcinoma, sebaceous carcinoma, and benign adnexal tumours like clear cell hidradenoma.

Malignant melanoma encompasses a spectrum of histopathological subtypes, each with unique clinical and cytological characteristics. Notably, balloon‐cell melanoma (BCM) emerges as an exceptionally rare and diagnostically challenging variant. Marked by the presence of distinct balloon‐like, clear cytoplasmic vacuoles within melanoma cells, BCM stands apart from other melanoma subtypes. Despite its rarity, the distinctive cytological features of BCM make it a compelling subject of investigation, emphasizing the crucial role of Fine Needle Aspiration (FNA) cytology in ensuring accurate diagnosis and guiding subsequent management decisions.

Myxoid neurofibroma masquerading as lymphatic-venous malformation and poses a diagnostic challenge on fine needle aspiration biopsy

BACKGROUND

Myxoid neurofibromas (NF) are uncommon, benign spindle cell tumors that originate from peripheral nerve sheaths, often posing a diagnostic challenge due to their hypocellularity on cytology specimens. Distinguishing myxoid spindle cell lesions can be challenging, given the broad range of potential differential diagnoses.

CASE PRESENTATION

A 26-year-old female with a past medical history of embolized inguinal, flank, and retroperitoneal venolymphatic malformation presented with a left pelvic pain causing significant disability. CT scan showed an extensive 8.7 cm × 6.6 cm retroperitoneal mass. FNA was performed and alcohol-fixed papanicolaou-stained smears showed a hypocellular specimen with loosely arranged clusters of bland spindle cell proliferation in the background of a mucoid matrix. Spindle cells showed scant cytoplasm and elongated oval-shaped regular nuclei. Prominent nucleoli were not seen. An excisional biopsy revealed a bland spindle cell proliferation in a myxoid background associated with shredded collagen bundles. Immunohistochemical staining showed diffuse positivity for S100 and CD34. Based on the overall findings, a definitive diagnosis of myxoid neurofibroma was rendered.

DISCUSSION

Cytological features of myxoid neurofibroma include the presence of hypocellular spindle-shaped cells arranged in small, loosely organized groups within a myxoid matrix background. Cells exhibit scant cytoplasm with regular oval and elongated nuclei. Nucleoli are typically not identified. The differential diagnosis includes myxoid neurofibroma, myxoma, myxoid liposarcoma, myxoid chondrosarcoma, myxoid dermatofibrosarcoma protuberans, low-grade fibromyxoid sarcoma, and low-grade myxo-fibrosarcoma.

CONCLUSION

We aim to highlight the importance of considering myxoid neurofibroma in the differential diagnosis of hypocellular myxoid spindle cell lesions encountered on fine-needle aspiration cytology.

Synchronous hepatocellular carcinoma and renal cell carcinoma: A cytological marvel

Multiple primary synchronous tumours have always created an inquisitiveness among clinicians, radiologists and pathologists. The diagnosis invariably proposes a challenge to diagnosticians. The coexistence of a primary hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC) is exceedingly rare, with countable number of cases being reported in literature. We report a pioneer case of 75-year-old male, having chronic hepatitis B, diagnosed with synchronous primary RCC and HCC in by fine-needle aspiration cytology (FNAC) and confirmed by immunohistochemistry.

FNA of Meningioma with Rhabdoid Features Presenting as a Lateral Neck Mass

Primary meningioma at extracranial head and neck sites is uncommon. Since fine needle aspiration (FNA) is often the first line diagnostic modality for the evaluation of masses in the head and neck, extracranial meningiomas can create a significant diagnostic pitfall for FNA. We report a case of meningioma with rhabdoid features and BAP1 loss in a 26-year-old woman, presenting as a large neck mass along the carotid sheath. FNA biopsy of the mass demonstrated a highly cellular specimen with clusters of uniform, epithelioid cells with round to ovoid nuclei and moderate nuclear to cytoplasmic ratio. An extensive immunohistochemical panel performed on cell block sections showed that the tumor cells were weakly EMA positive, progesterone receptor was focally positive, and SSTR2A was diffuse and strongly positive. BAP1 immunohistochemistry showed a diffuse loss of expression in the tumor cells. After the cytologic diagnosis of meningioma, a tissue biopsy was performed, and the diagnosis of meningioma with rhabdoid features and BAP1 loss was confirmed. We also perform a literature review of meningioma cases presenting as a neck mass and evaluated by FNA. Our case highlights the significant diagnostic challenges that can be caused by extracranial meningiomas on FNA and the importance of ancillary studies to avoid diagnostic pitfalls.

Malignancy Risk of Follicular Neoplasm (Bethesda IV) With Variable Cutoffs of Tumor Size: A Systemic Review and Meta-Analysis

CONTEXT

The decision on diagnostic lobectomy for follicular neoplasms (FN) is challenging.

OBJECTIVE

This meta-analysis investigates whether an appropriate size cutoff exists for recommending surgery for thyroid nodules diagnosed as FN by fine needle aspiration.

METHODS

The Ovid-Medline, EMBASE, Cochrane, and KoreaMed databases were searched for studies reporting the malignancy rate of FN/suspicious for FN (FN/SFN) according to tumor size, using search terms "fine needle aspiration," "follicular neoplasm," "lobectomy," "surgery," and "thyroidectomy."

RESULTS

Fourteen observational studies comprising 2016 FN/SFN nodules with postsurgical pathologic reports were included, and 2 studies included malignancy rates with various tumor sizes. The pooled malignancy risk of FN/SFN nodules according to size was: odds ratio (OR) 2.29 (95% CI, 1.68-3.11) with cutoff of 4 cm (9 studies), OR 2.39 (95% CI, 1.45-3.95) with cutoff of 3 cm (3 studies), and OR 1.81 (95% CI, 0.94-3.50) with cutoff of 2 cm (5 studies). However, tumors ≥2 cm also showed a higher risk (OR 2.43; 95% CI, 1.54-3.82) based on the leave-one-out meta-analysis after removal of 1 influence study. When each cutoff size was evaluated by summary receiver operating characteristic (sROC) curves, the cutoff of 4 cm showed the highest summary area under the curve (sAUC, 0.645) compared to other cutoffs (sAUC, 0.58 with 2 cm, and 0.62 with 3 cm), although there was no significant difference.

CONCLUSION

Although the risk of malignancy increases with increasing tumor size, the risk remains significant at all tumor sizes and no cutoff limit can be recommended as a decision-making parameter for diagnostic surgery in Bethesda IV thyroid nodules.

Diagnostic Sensitivity of Abdominal Fat Aspiration Biopsy for Cardiac Amyloidosis: A Systematic Review and Meta-Analysis

Introduction. Cardiac amyloidosis is a lethal disease, the incidence of which is increasing every year. Early diagnosis and treatment are the keys to reducing the mortality of this disease. Methods. Relevant English literature published in Embase, PubMed, Cochrane Library, and Web of Science were searched until December 1, 2022. Meta-analysis was performed with Stata 17.0 software. Results. A total of 1060 patients with 5 articles were included in this study. The sensitivity of abdominal fat aspiration biopsy for the diagnosis of cardiac amyloidosis was 0.66 (0.48-0.84) and the sensitivity for light chain amyloidosis cardiomyopathy and transthyretin amyloidosis cardiomyopathy was 0.90 (0.80-0.97) and 0.39 (0.18-0.60), respectively. Conclusion. Abdominal fat aspiration biopsy has high sensitivity and clinical value in the diagnosis of light chain amyloidosis cardiomyopathy, whereas there are limitations in the diagnosis of transthyretin amyloidosis cardiomyopathy.

Cytomorphological comparison of ThinPrep and SurePath liquid-based cytology in thyroid fine-needle aspiration

BACKGROUND

The two widely established systems for liquid-based cytology (LBC), ThinPrep and SurePath, employ different principles. The aim of this study was to compare the cytomorphology of thyroid lesions prepared by the two techniques.

METHODS

We retrospectively reviewed 44 thyroid FNA specimens prepared by LBC, including 20 ThinPrep and 22 SurePath. Cytologic diagnoses were made according to the Bethesda system and cytomorphologic parameters were evaluated.

RESULTS

Acellular smears were significantly frequent in ThinPrep than SurePath (10% vs. 0%). Both techniques produced a clean background, well cell preservation, and not apparent cell shrinkage. ThinPrep showed significantly lower cellularity than SurePath (25% vs. 4.3%). ThinPrep produced considerable flattening and fragmented clusters, while SurePath contained larger clusters in a three-dimensional configuration. Colloid was significantly reduced in amount and fragmented in ThinPrep, and was easily observed in SurePath. In cases of Hashimoto's thyroiditis, ThinPrep produced much less leukocytes in background than SurePath. Aggregates of fibrin and leukocytes were frequently present in 10/16 cases (62.5%) processed by ThinPrep. Air-dry artifact at periphery of the ring was present in 6/16 cases (37.5%) processed by ThinPrep. The nuclear features of papillary carcinoma were similarly evident in both LBC preparations.

CONCLUSION

SurePath seems to be superior to ThinPrep for diagnosing benign entities based on adequate representation of colloid and lymphocytes. The cell quality of both techniques in thyroid FNA was comparable, while each method introduces its own unique cytologic artifacts related to its methodology. We should recognize the cytomorphologic alterations to avoid misinterpretations.

Value of repeated US-guided fine-needle aspiration (US-FNAB) in the follow-up of benign thyroid nodules: a real-life study based on the MoCyThy (Modena's Cytology of the Thyroid) DATABASE with a revision of the literature

PURPOSE

The utility of repeating ultrasound-guided fine-needle aspiration (US-FNAB) in the follow-up of benign (THY2) thyroid nodules is still debated. The aim of this study was to retrospectively investigate the diagnostic value of re-biopsy of thyroid nodules following an initially benign result.

METHODS

We retrospectively analyzed US-FNABs performed at the Unit of Endocrinology of Modena from 2006 to 2009. The firstly benign cytological result was compared with the cytological results of subsequent US-FNABs (2nd and/or 3rd) executed on the same nodule.

RESULTS

Among 10449 US-FNABs, 6270 (60%) received a THY2 cytological categorization. Of them, 278 (4.43%) underwent a subsequent US-FNAB: 86.7% maintained the same cytology, 32 (11.5%) changed to THY3 (indeterminate) and 5 (1.8%) to THY4 (suspicious of malignancy). Among the 24 nodules addressed to surgery, 9 (37%) were histologically malignant, with an overall miss rate of 3.2%. Male patients had higher risk of discordant results at subsequent US-FNAB (p = 0.005, OR:3.59, 95%CI:1.453-7.769) while dimensional increase above 5 mm was predictive of concordant benign cytology (p = 0.036, OR:0.249, 95%CI:0.068-0.915). Age, suspicious US characteristics, and distance between US-FNABs resulted not predictive.

CONCLUSIONS

Re-biopsy of benign nodules confirmed the benign nature in most cases. In case of discordant cytology, relocation in indeterminate category was the most common. The histological diagnosis of cancer occurred in one quarter of nodules surgically removed, with a low overall clinically significant miss rate. Thus, a small percentage of false negatives exists; males and subjects with US suspicious nodules should be carefully followed-up, considering case by case re-biopsy possibility.

Fine needle aspiration of spindle cell lipoma-Lochkern cells as a clue for diagnosis: A case arising in the parotid gland

Spindle cell lipoma (SCL) is a rare form of lipoma, typically occurring as a mass in the back, shoulder or posterior neck of adult males. Most cases present little diagnostic difficulty on fine needle aspiration (FNA), but can be problematic when the SCL is in an unusual location. The authors report a case in the parotid gland in a 75-year-old man. FNA was paucicellular and showed loose collections of spindle cells with mild to moderate atypia, admixed with ropy collagen fibers on a myxoid background. The nuclei showed occasional angulation, interpreted on FNA as suspicious for myoepithelial tumor or low-grade sarcoma. The subsequent excisional specimen was diagnosed as SCL. On retrospective review of the FNA, an additional finding was recognized: 'naked' nuclei with intranuclear lipid vacuoles and positive immunostaining for S100 protein, consistent with Lochkern cells of mature adipocytes. This case highlights the challenges of diagnosing SCL on cytology when no fat-containing cells are apparent on the smear, and stresses the significance of Lochkern cells as a clue for diagnosis.

Assessing Adequacy: A Meta-Analysis of Rapid Onsite Evaluation of Thyroid Nodules

INTRODUCTION

Fine-needle aspiration (FNA) is the standard form of preoperative evaluation of thyroid nodule cytological status. A significant number FNAs are classified as inadequate for interpretation, requiring a repeat FNA which is potentially avoidable, costly, and delays treatment. To address these concerns and maximize first-time FNA adequacy, rapid onsite evaluation (ROSE) of FNA specimens was introduced. Our study aims to determine the impact of ROSE on FNA adequacy.

METHODS

PubMed, Embase, and Web of Science were searched for primary articles assessing the adequacy of ROSE in thyroid nodules.

RESULTS

A total of 17 studies were included for a total of 24,649 thyroid nodes. Thirteen thousand two hundred fifteen (53.6%) thyroid nodules were assessed utilizing ROSE and 11,434 (46.4%) were not. Pooled adequacy increased significantly from 76% without ROSE to 92% with rose (P = 0.001). Use of ROSE increased the odds of adequate FNA by 22% (risk ratio (RR) = 1.22, 95% confidence interval (CI) = 1.12-1.32). At institutions with less than 85% effective diagnostic adequacy without ROSE, the risk for diagnostic adequacy increased by 28% with ROSE implementation (RR = 1.28, 95% CI = 1.20-1.37). In contrast, in studies reported from institutions with an effective diagnostic rate greater than 85% without the use of ROSE, the diagnostic adequacy only increased by 5% with ROSE implementation (RR = 1.05, 95% CI = 1.03-1.06).

CONCLUSIONS

The use of ROSE during first-time FNA of thyroid nodules can significantly improve adequacy, especially at institutions with baseline high inadequacy rates. Implementation of ROSE can reduce repeat FNAs and its associated consequences.

Assessing the Frequency of Deferrable Thyroid Nodule Biopsies to De-escalate Low-Value Care

OBJECTIVE

Thyroid nodules are common, yet fewer than 1 in 10 harbors malignancy. When present, thyroid cancer is typically indolent with excellent survival. Therefore, patients who are not candidates for thyroid cancer treatment due to comorbid disease may not require further thyroid nodule evaluation. The goal of this study was to determine the rate of deferrable thyroid nodule biopsies in patients with limited life expectancy.

METHODS

We identified patients who underwent thyroid fine needle aspiration (FNA) between 2015 and 2018 at our institution. The primary outcome was the number of deferrable FNAs, defined as FNAs performed in patients who died within 2 years after biopsy. Secondary outcomes included cytologic Bethesda score, procedure costs, and final diagnosis on surgical pathology. Multivariable logistic and Cox proportional hazards regressions were used to evaluate factors associated with FNA in patients with limited life expectancy.

RESULTS

A total of 2565 FNAs were performed. Most patients were female (79%), and 37 (1.5%) patients died within 2 years. Nonthyroid specialists were significantly more likely to order deferrable FNAs (odds ratio 4.13, P < .001). Of the patients who died within 2 years, most (78%) had a concomitant diagnosis of nonthyroid cancer, and 4 went on to have thyroid surgery (Bethesda scores: 3, 4, 4, and 6). Spending associated with deferrable FNAs and subsequent surgery totaled over $98 000.

CONCLUSIONS

Overall, the rate of deferrable thyroid nodule biopsies was low. However, there is an opportunity to reduce low-value biopsies in patients with a concurrent nonthyroid cancer by partnering with oncology providers.

Chronic Nonspinal Osteomyelitis in Adults: Consensus Recommendations on Percutaneous Bone Biopsies from the Society of Academic Bone Radiologists

The diagnosis and management of chronic nonspinal osteomyelitis can be challenging, and guidelines regarding the appropriateness of performing percutaneous image-guided biopsies to acquire bone samples for microbiological analysis remain limited. An expert panel convened by the Society of Academic Bone Radiologists developed and endorsed consensus statements on the various indications for percutaneous image-guided biopsies to standardize care and eliminate inconsistencies across institutions. The issued statements pertain to several commonly encountered clinical presentations of chronic osteomyelitis and were supported by a literature review. For most patients, MRI can help guide management and effectively rule out osteomyelitis when performed soon after presentation. Additionally, in the appropriate clinical setting, open wounds such as sinus tracts and ulcers, as well as joint fluid aspirates, can be used for microbiological culture to determine the causative microorganism. If MRI findings are positive, surgery is not needed, and alternative sites for microbiological culture are not available, then percutaneous image-guided biopsies can be performed. The expert panel recommends that antibiotics be avoided or discontinued for an optimal period of 2 weeks prior to a biopsy whenever possible. Patients with extensive necrotic decubitus ulcers or other surgical emergencies should not undergo percutaneous image-guided biopsies but rather should be admitted for surgical debridement and intraoperative cultures. Multidisciplinary discussion and approach are crucial to ensure optimal diagnosis and care of patients diagnosed with chronic osteomyelitis.

Primary lacrimal sac melanoma: a case report describing the novel use of fine needle aspiration cytology (FNAC) for diagnosis, together with literature review and immunotherapy treatment update

Primary lacrimal sac melanoma (PLSM) is exceedingly rare and associated with high morbidity and mortality. Unfortunately, PLSM often presents insidiously resulting in delayed detection and poor prognosis. A 69-year-old Black man was suspected of having a lacrimal sac tumour following presentation with a left sided watery eye, bloody tears, and a lacrimal mass. Due to the patient's implantable pacemaker, defibrillator, and high anticoagulation, an ultrasound-guided FNAC was performed instead of incisional biopsy, revealing a PLSM. Diagnosis was confirmed following complete tumour resection with free flap reconstruction and neck dissection. Unfortunately, disease progression ensued despite further neck dissection and three cycles of both pembrolizumab and iplimumab. This is the first description of FNAC to accurately diagnose PLSM and highlights its use as an accurate, rapid, and minimally invasive technique that may allow an earlier screening diagnosis of lacrimal sac tumours. We also discuss the outcome of immunotherapy in recent similar cases.

Molecular Profiling for Bethesda III to VI Nodules: Results of a Multicenter International Retrospective Study

OBJECTIVE

Molecular testing is a well-established tool that assists in the management of thyroid nodules. We describe our experience using molecular testing of thyroid nodules with Bethesda III to VI cytology.

METHODS

This is a retrospective multicenter, multinational study of thyroid nodules that underwent preoperative molecular profiling with ThyGenX/ThyGeNEXT or ThyroSeq V3 between 2015 and 2022. The clinical characteristics and mutational profiles of tumors were compared. Collected data included demographics, cytology results, surgical pathology, and molecular alterations. Molecular alterations were categorized into 3 main phenotypes: BRAF-like, RAS-like, and non-BRAF-non-RAS (NBNR).

RESULTS

Overall, 784 patients who had surgery were included, of which 603 (76.2%) were females. The most common histologic type was papillary thyroid cancer (PTC) with 727 (91.9%) cases. In total, 205 (28.2%) cases showed an aggressive subtype of PTC (eg, tall cell and hobnail). BRAF-like alterations were most likely to be found in Bethesda V and VI nodules and show extrathyroidal extension (ETE), nodal disease, and/or aggressive subtypes of PTC (P < .001 for all). RAS-like alterations were more commonly found in Bethesda III and IV nodules and were less likely to show ETE, nodal disease, and/or aggressive histology (P < .001 for all). NBNR alterations were more commonly found in Bethesda III and IV nodules and were less likely to show ETE, nodal disease, and/or aggressive subtypes of PTC. However, they were rarely but significantly associated with poorly differentiated thyroid cancer (P < .005).

CONCLUSION

Molecular testing of thyroid nodules can help determine the likelihood of malignancy and classify nodules into several tumor phenotypes, predicting their behaviors and potentially allowing for a more tailored treatment. NBNR alterations should be managed with caution.

A Curious Case of Omental Oxalate Crystals in a Patient With Struma Ovarii: Pointers to an Unusual Clinicopathological Scenario

Percutaneous image-guided biopsies are becoming increasingly common in routine pathology practice, with the greater omentum emerging as a common target. We present herein an account of a middle-aged lady with a complex ovarian mass, omental thickening, and raised serum CA125; clinically suspected to have advanced ovarian malignancy. Fine needle aspiration cytology (FNAC) from the ovarian mass was inconclusive. Omental biopsy revealed only refractile, birefringent crystalline material with surrounding foreign body giant cell reaction; thus surprising the clinical team. Subsequent resection of the ovarian mass showed a teratoma composed exclusively of thyroid tissue, diagnosed as struma ovarii. The omental crystals, interpreted as calcium oxalate crystals, were possibly a consequence of colloid seeding during the ovarian mass FNAC.

The spectrum of cytological findings in patients with BCG lymphadenitis: A series of 13 cases

CONTEXT

Bacillus Calmette-Guérin (BCG) vaccine has been used to prevent tuberculosis and/or its severe complications for long. BCG lymphadenitis is a common complication of the vaccine, which is sometimes subjected to cytological examination. The aim of the study is to describe the cytological findings of BCG lymphadenitis.

SETTINGS

The study was conducted in a tertiary care hospital in the western part of India from January 2021 to December 2022.

DESIGN

The study was performed on archived material of all patients who were referred to the fine needle aspiration clinic for cytology examination. Clinical and pathological data of cases were retrieved, and cases of BCG lymphadenitis were selected in the study based on these data. Slides of cases were retrieved, and cytological findings were studied.

MATERIALS AND METHODS

Papanicolaou, Giemsa, and Hematoxylin & eosin-stained smears, as well as Ziehl-Neelson stain (Z.N. stain) smears of all BCG lymphadenitis cases, were retrieved. Cases were reviewed for individual cytological features and overall cytological diagnostic categories. Z.N. stain smears were evaluated for acid-fast bacilli.

RESULTS AND CONCLUSIONS

Diagnostic categories observed in BCG lymphadenitis include suppurative lymphadenitis/abscess (15 %), necrotizing lymphadenitis (23 %), necrotizing granulomatous lymphadenitis (46 %), suppurative granulomatous lymphadenitis (8 %), non-necrotizing granulomatous lymphadenitis (8 %). Acid-fast bacilli were detected by Z.N. stain in 8 cases (62 %). The cytological findings of BCG lymphadenitis closely overlap with those of tuberculous lymphadenitis. So, clinical context is very important while reporting isolated axillary lymphadenopathy, specifically in recently vaccinated infants, to avoid misdiagnosis as tuberculous lymphadenitis.

Grading medullary thyroid carcinoma on fine-needle aspiration cytology specimens with the International Medullary Thyroid Carcinoma Grading System: A cytologic-histologic correlation

BACKGROUND

Medullary thyroid carcinoma (MTC) is a rare cancer of parafollicular C-cell origin. The International MTC Grading System (IMTCGS) incorporates mitotic activity, the presence of necrosis, and the Ki67 proliferation rate (PR) to classify MTCs as low or high grade. The ability to predict IMTCGS grade in cytology was assessed.

METHODS

MTCs with cytology and subsequent surgical follow-up were reviewed. Cytology slides were reviewed for mitotic figures, apoptoses, and necrosis, and a Ki67 PR was calculated when possible. Findings were correlated with final IMTCGS grade.

RESULTS

Twenty-five MTC fine-needle aspirations (FNAs) were identified, with nine identified as high grade (36%). By using a PR cutoff of 5%, Ki67 on FNA material (Ki67FNA) showed 92% concordance (n = 22 of 24) with surgical Ki67 and a correlation coefficient (R2) of 0.72. Sensitivity and specificity of Ki67FNA for predicting high-grade MTC were 38% and 100%, respectively. Multiple mitotic figures were present in a single slide of 43% (n = 3 of 7) of evaluable high-grade MTCs, whereas only one of 16 low-grade MTCs showed a single mitotic figure. Definitive apoptoses were present in five of seven high-grade MTC FNAs but were absent in 16 low-grade MTCs. The sensitivity and specificity of apoptoses/necrosis on cytology for high-grade MTCs were 71% and 88%, respectively.

CONCLUSIONS

Ki67FNA ≥5% shows low sensitivity but high specificity for predicting high-grade MTC. The presence of multiple mitotic figures in a single slide or definitive apoptotic bodies are both highly suggestive of high-grade MTC, and should warrant a close examination for necrosis and a careful Ki67 PR count.

Diagnostic Accuracy of Fine Needle Aspiration Cytology as Compared to Histopathology in Parotid Gland Swelling

BACKGROUND

The diagnosis of parotid swelling is challenging and investigations like imaging and needle aspiration cytology are helpful. The objective of this study was to determine the diagnostic accuracy of fine needle aspiration cytology (FNAC) as compared to the histopathology in parotid gland swelling.

METHODS

It was a descriptive cross sectional study carried out in the Department of ENT-Head and Neck Surgery, Tribhuvan University Teaching Hospital, Institute of Medicine, Kathmandu by reviewing the medical record charts of the patients who had undergone surgery for parotid lesions during the study period of seven and half years. All patients whose fine needle aspiration cytology and histopathology reports were available were included in the study. The data were presented as mean, standard deviation, ratio and percentages. Microsoft excel was used for data analysis.

RESULTS

There were 75 patients included in the study. The age ranged from nine years to 78 years and the mean age being 38.3 17.42 years. The male to female ratio was 1:1.78. The concordance rate between fine needle aspiration cytology and histopathology was 82.7%. The sensitivity and specificity of the fine needle aspiration cytology were 80% and 95% respectively. Similarly, the positive predictive and negative predictive values were 84% and 93% respectively. The diagnostic accuracy of the fine needle aspiration cytology was 91% for the parotid swelling in our study.

CONCLUSIONS

The diagnostic accuracy of fine needle aspiration cytology for parotid swellings in our study was excellent. The result of fine needle aspiration cytology is helpful in deciding management plan for parotid lesions.

[Stratified application of gene expression in diagnosis of thyroid nodules]

Objective: To investigate the value of BRAF V600E and multigene detection and stratified application for the diagnosis of thyroid nodules. Methods: A total of 1 117 patients with thyroid nodules resection at Nanjing Gulou Hospital from December 2020 to July 2022 were enrolled in the study. Fine needle aspiration (FNA) and core biopsy samplings were performed for cytopathologic examination and genetic testings; the findings were combined with BSRTC classification. The diagnostic performance of BRAF V600E and multigene detection were compared. Results: Among the 1, 117 patients who underwent thyroid nodules resection, 285 were male and 832 were female, with a median age of 46 years (range: 24-76 years). Postoperative histopathologic examination confirmed 1 040 cases of thyroid cancer and 77 cases of benign nodules. The sensitivity (87.0% vs. 80.8%, P<0.01) and diagnostic accuracy (87.9% vs. 82.1%, P<0.01) of multigene detection were significantly higher than those of BRAF V600E detection. The result of multigene detection showed that BRAF V600E mutation was the most common finding, followed by CCDC6-RET (E1-E12) fusion, ETV6-NTRK3 fusion, and KRAS mutation. Multigene detection had a higher sensitivity (81.9% vs. 72.8%, P<0.01) and lower cancer risk in wild-type (47.6% vs. 57.7%, P=0.069) than BRAF V600E detection in BSRTCⅠ-Ⅴ lesions. Compared with BRAF V600E detection, multigene had no significant difference of sensitivity in BSRTC Ⅰ lesions, but significantly higher sensitivity (86.3% vs 74.0%, P<0.01) in BSRTC Ⅲ lesions. Conclusions: Genetic detection can be used as an effective tool for the diagnosis of thyroid nodules. A stratified application of molecular markers in the diagnosis of thyroid nodules is proposed. Combined with FNA, single gene or multigene detection both can effectively assist in the diagnosis of thyroid nodules. Moreover, multigene detection is superior to single gene detection. For BSRTC Ⅲ lesion with wild-type BRAF, multigene detection can be considered with a repeated FNA.

Cytopathological analysis of salivary gland cancer: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the indications for fine-needle cytology and the modalities of frozen section pathological analysis in the management of salivary gland cancer.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group who drafted a narrative review of the literature published on Medline and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group according to the formal consensus method.

RESULTS

Fine-needle cytology is recommended as part of the diagnostic work-up for a major salivary gland tumor suspicious for malignancy. Fine-needle cytology should be performed after MRI to avoid artifacts. Frozen section analysis is recommended to confirm the malignant nature of the tumor, to adapt the extent of resection and to indicate neck dissection. Whenever possible, the entire tumor and adjacent salivary or periglandular tissue should be sent for frozen section analysis.

CONCLUSION

Fine-needle cytology and frozen section analysis play an essential role in the management of salivary gland cancers.

Second edition of the Milan System for Reporting Salivary Gland Cytopathology: Refining the role of salivary gland FNA

The use of standardised reporting systems for non-gynaecologic cytopathology has made enormous gains in popularity during the past decade, including for thyroid fine-needle aspiration, urine cytology, serous effusions, pancreas, lymph nodes, lung and more. In February 2018, the first edition of the Atlas of the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was published. The MSRSGC defines six diagnostic fine-needle aspiration categories encompassing the spectrum of non-neoplastic, benign and malignant lesions of the salivary glands. The goal of the MSRSGC is to combine each diagnostic category with a defined risk of malignancy and a specific clinical and/or surgical management algorithm. Since its initial publication in 2018, more than 200 studies and commentaries have been published, confirming the role of the MSRSGC. The second edition of the MSRSGC, published in July 2023, includes refined risks of malignancy based on systematic reviews and meta-analyses, a new chapter summarising the use of salivary gland imaging, new advances in ancillary testing and updates in nomenclature.

Decoding the rhabdoid riddle in liver: A rare case of primary hepatic malignant rhabdoid tumor with a comprehensive literature review

Malignant rhabdoid tumor of the liver is a rare, highly aggressive primary hepatic malignancy occurring primarily in infants. Establishing a definitive diagnosis is challenging due to its rarity, non-specific clinicoradiologic findings, and overlapping morphologic features. Herein, we present the cytomorphologic and immunocytochemical characteristics of a rare case of primary hepatic Malignant rhabdoid tumor (MRT) in an infant. A 5-month-old female child presented with progressively increasing firm mass in the upper abdomen, progressive pallor, sudden onset respiratory distress, and difficulty feeding. On examination, the child had massive, firm nodular hepatomegaly. Ultrasonography of the abdomen revealed a heterogeneously hypoechoic lesion in the left lobe of the liver. Serum alpha-fetoprotein levels were within normal limits. An ultrasound-guided fine-needle aspiration cytology (FNAC) from the liver mass showed predominantly dispersed large, markedly pleomorphic tumor cells with round to oval eccentrically placed nuclei, prominent nucleoli, and moderate cytoplasm. On immunocytochemistry, tumor cells showed positivity for vimentin, cytokeratin, and EMA and demonstrated a loss of INI1, confirming the diagnosis of MRT. The index report highlights the distinctive clinicopathological features of a hepatic malignant rhabdoid tumor along with the key differential diagnoses, which may pose a diagnostic conundrum. A high index of clinical suspicion and a thorough understanding of its cytomorphological and immunochemical characteristics are crucial for an accurate diagnosis.

American Society of Cytopathology Telecytology validation recommendations for rapid on-site evaluation (ROSE)

Telecytology has multiple applications, including rapid onsite evaluation (ROSE) of fine-needle aspiration (FNA) specimens. It can enhance cytopathology practice by increasing productivity, reducing costs, and providing subspecialty expertise in areas with limited access to a cytopathologist. However, there are currently no specific validation guidelines to ensure safe practice and compliance with regulations. This initiative, promoted by the American Society of Cytopathology (ASC), intends to propose recommendations for telecytology implementation. These recommendations propose that the validation process should include testing of all hardware and software, both separately and as a whole; training of all individuals who will participate in telecytology with regular competency evaluations; a structured approach using retrospective slides with defined diagnoses for validation and prospective cases for verification and quality assurance. Telecytology processes must be integrated into the laboratory's quality management system and benchmarks for discrepancy rates between preliminary and final diagnoses should be established and monitored. Special attention should be paid to minimize discrepancies that downgrade malignant cases to benign (false positive on telecytology). Currently, billing and reimbursement codes for telecytology are not yet available. Once, they are, recommendation of the appropriate usage of these codes would be a part of the recommendations. These proposed guidelines are intended to be a resource for laboratories that are considering implementing telecytology. These recommendations can help to ensure the safe and effective use of telecytology and maximize its benefits for patients.

Ultrasound radiomics based XGBoost model to differential diagnosis thyroid nodules and unnecessary biopsy rate: Individual application of SHapley additive exPlanations

OBJECTIVES

Radiomics-based eXtreme gradient boosting (XGBoost) model was developed to differentiate benign thyroid nodules from malignant thyroid nodules and to prevent unnecessary thyroid biopsies, including positive and negative effects.

METHODS

The study evaluated a data set of ultrasound images of thyroid nodules in patients retrospectively, who initially received ultrasound-guided fine-needle aspiration biopsy (FNAB) for diagnostic purposes. According to ACR TI-RADS, a total of five ultrasound feature categories and the maximum size of the nodule were determined by four radiologists. A radiomics score was developed by the LASSO algorithm from the ultrasound-based radiomics features. An interpretative method based on Shapley additive explanation (SHAP) was developed. XGBoost was compared with ACR TI-RADS for its diagnostic performance and FNAB rate and was compared with six other machine learning models to evaluate the model performance.

RESULTS

Finally, 191 thyroid nodules were examined from 177 patients. The radiomics score were calculated using 8 features, which were selected among 789 candidate features generated from the ultrasound images. The model yielded an AUC of 93% in the training cohort and 92% in the test cohort. It outperformed traditional machine learning models in assessing the nature of thyroid nodules. Compared with ACR TI-RADS, the FNAB rate decreased from 34% to 30% in training and from 35% to 41% in test.

CONCLUSIONS

The radiomics-based XGBoost model proposed could distinguish benign and malignant thyroid nodules, thereby reduced significantly the number of unnecessary FNAB. It was effective in making preoperative decisions and managing selected patients using the SHAP visual interpretation tools.

Fine-needle aspiration cytology of presacral myelolipoma: Cytomorphological features of a rare entity and review of the literature

Presacral myelolipoma is an uncommon benign tumor, and its diagnosis can be challenging oncytology specimens. This case emphasizes the importance of fine needle aspiration cytology as an initial and valuable diagnostic tool for evaluating presacral masses. The identification of a combination of mature adipose tissue and hematopoietic elements in varying proportions is a crucial feature in FNA cytology. This underscores the role of FNA cytology in providing an accurate diagnosis and guiding subsequent management decisions.

A Comprehensive Approach to the Thyroid Bethesda Category III (AUS) in the Transition Zone Between 2nd Edition and 3rd Edition of The Bethesda System for Reporting Thyroid Cytopathology: Subcategorization, Nuclear Scoring, and More

Significant interobserver variabilities exist for Bethesda category III: atypia of undetermined significance (AUS) of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). Thus, subcategorization of AUS including AUS "nuclear" and AUS "other" is proposed in the recent 3rd edition of TBSRTC. This study investigated the impact of the nuclear features/architectural features/nuclear score (NS) (3-tiered)/subcategories and subgroups on risk of malignancy (ROM) in thyroid fine-needle aspirations (FNA). 6940 FNAs were evaluated. 1224 (17.6%) cases diagnosed as AUS were reviewed, and 240 patients (initial FNAs of 260 nodules and 240 thyroidectomies) were included. Subcategories and subgroups were defined according to TBSRTC 2nd and 3rd editions. Histological diagnostic groups included nonneoplastic disease, benign neoplasm, low-risk neoplasm, and malignant neoplasm. Overall, ROM was 30.7%. ROM was significantly higher in FNAs with nuclear overlapping (35.5%), nuclear molding (56.9%), irregular contours (42.1%), nuclear grooves (74.1%), chromatin clearing (49.4%), and chromatin margination (57.7%), and these features were independent significant predictors for malignancy. FNAs with NS3 had significantly higher ROM (64.2%). Three-dimensional groups were significantly more frequent in malignant neoplasms (35.7%). ROM was significantly higher in AUS-nuclear subcategory (48.2%) and in AUS-nuclear and architectural subcategory (38.3%). The highest ROM was detected in AUS-nuclear1 subgroup (65.2%). ROM was significantly higher in the group including AUS-nuclear and AUS-nuclear and architectural subcategories, namely "high-risk group" than the group including other subcategories, namely "low-risk group" (42.0%vs 13.9%). In conclusion, subcategorization may not be the end point, and nuclear scoring and evaluation of architectural patterns according to strict criteria may provide data for remodeling of TBSRTC categories.

An old friend, a new insight: Calcitonin measurement in serum and aspiration needle washout fluids significantly increases the early and accurate detection of medullary thyroid cancer

BACKGROUND

The sensitivity of cytological (CY) evaluation after fine-needle aspiration (FNA) for detecting medullary thyroid carcinoma (MTC) is a subject of controversy. The routine use of serum calcitonin (CT) in patients with thyroid nodules is not universally adopted. The authors conducted CT screening of FNA washout fluid (FNA-CT) to address the diagnostic challenges. The objective was to assess the contributions of serum CT, FNA cytology (FNA-CY), and FNA-CT to the diagnosis.

METHODS

Between February 2019 and June 2022 (group 1), the authors prospectively screened the CT of patients with thyroid nodules. Both FNA-CY and FNA-CT were performed for patients with persistently elevated CT values. The sensitivity of FNA-CY, serum CT, and FNA-CT for accurate diagnosis was evaluated. Additionally, the authors retrospectively examined data from patients with thyroid nodules before CT screening (2008-2019) (group 2). They compared the characteristics of MTC patients in groups 1 and 2.

RESULTS

MTC was identified in 30 patients (0.25%) in group 1 and 19 (0.07%) in group 2. A FNA-CT cutoff value of 4085.5 pg/mL detected MTC with a sensitivity of 96.8%, and a serum CT cutoff value of 28.3 pg/mL detected MTC with a sensitivity of 86.7%. In contrast, FNA-CY detected MTC with a sensitivity of 42.4%. In group 1, 18 patients (60%) with MTC were diagnosed with microcarcinoma, whereas only two patients (10.5%) in group 2 had microcarcinoma.

CONCLUSIONS

This study detected MTC earlier by routinely measuring serum CT in all patients with nodular thyroid disease and performing FNA-CT in those with elevated values. FNA-CT and serum CT sensitivities were significantly higher than those of FNA-CY. This study revealed different FNA-CT cutoff values compared to other studies, emphasizing the need for determining clinic-specific cutoff values.

Comprehensive evaluation of benign and malignant etiologies of different serous effusions with the International System for Reporting Serous Fluid Cytopathology: A multi-institutional study in Taiwan

BACKGROUND

The International System for Reporting Serous Fluid Cytopathology (ISRSFC) was introduced globally in 2019 in response to the absence of a standardized reporting system for serous fluid cytology. This study presents experiences implementing this system across three distinct hospitals in Taiwan.

METHODS

A total of 6177 serous fluid specimens in three hospitals in Taiwan between 2018 and 2020 were retrospectively reviewed and reclassified according to the ISRSFC. Cytohistological correlation and chart review were further performed to investigate etiologies and risks of malignancy (ROMs).

RESULTS

Reclassification showed that 34 (0.7%) of 4838 pleural effusions were nondiagnostic (ND), 4086 (84.5%) were negative for malignancy (NFM), 201 (4.2%) were atypia of undetermined significance (AUS), 92 (1.9%) were suspicious for malignancy (SFM), and 425 (8.8%) were malignant (MAL). The 1231 ascites cases contained 13 (1.1%) ND, 1004 (81.6%) NFM, 53 (4.3%) AUS, 31 (2.5%) SFM, and 130 (10.6%) MAL specimens. In pleural effusions, the ROM was 2.9% for ND, 14.0% for NFM, 52.2% for AUS, 85.9% for SFM, and 95.1% for MAL. In ascites, it was 15.4% for ND, 19.1% for NFM, 52.8% for AUS, 83.9% for SFM, and 92.3% for MAL. In pericardial effusions, it was 0.0% for ND, 11.6% for NFM, 30.8% for AUS, 100.0% for SFM, and 95.2% for MAL. Different effusions' most common benign and malignant etiologies were also disclosed.

CONCLUSIONS

These multi-institutional data have determined the diagnostic usefulness of the ISRSFC, which provides pathologists and physicians with invaluable assistance in correctly classifying effusions for further management.

Usual breast lump with unusual features

The co-existence of granulomatous mastitis and collagenous spherulosis in a breast lump is an uncommon finding. The awareness of cytomorphological features can help corroborate a cytological diagnosis. A palpable breast lump in an elderly female warrants urgent attention and fine needle aspiration is a rapid, reliable method of evaluation. An elderly female with a firm breast lump mimicking malignancy was subjected to fine needle aspiration cytology (FNAC). Smears showed ill-formed granulomas, inflammatory cells and homogeneous hyaline stromal globular elements intermingled with the benign ductal epithelial and myoepithelial cells.

Cutaneous eccrine spiradenoma: Insights into cytomorphological features via fine needle aspiration biopsy and a comprehensive literature review

Eccrine spiradenoma (ES) is an uncommon and benign adnexal tumour originating from sweat glands. The cytological examination of ES poses a diagnostic challenge, as it can be mistaken for various benign and malignant basaloid skin neoplasms. The cytomorphologic features of ES are infrequently documented in existing literature. This study seeks to present a thorough exploration of the cytomorphologic traits associated with ES, accompanied by an analysis of ancillary testing that contribute to the accurate identification of this entity in cytological specimens.

Eccrine spiradenoma is infrequently encountered in fine needle aspiration (FNA) cytopathology, and the available literature on its cytomorphologic features is limited. The challenge arises from its similarity to other benign and malignant dermal basaloid neoplasms, emphasizing the critical role of clinicopathologic correlation and immunohistochemical staining in achieving a precise diagnosis.

Commentary on small-volume biopsy of follicular lymphoma: Practical issues in the molecular era

Follicular lymphoma (FL) is a common subtype of non-Hodgkin lymphoma derived from germinal center B-cells. Small-volume biopsies (SVBs), including fine-needle aspiration, needle core biopsy, and cell blocks, are often used for the assessment of patients with FL. Recently, Fitzpatrick et al. found that additional biopsies were frequently needed to supplement SVB for the initial diagnosis of FL. However, regardless of the type of SVB used, additional biopsies were usually not necessary for assessments for transformed or recurrent FL. Their multi-institutional study reflects the fact that SVB may be sufficient for clinical decision-making in these medical settings, although surgical excision is the gold standard for a definitive diagnosis of FL. With ancillary tests and advances in molecular testing, SVB has become increasingly popular and helpful, although there are practical limitations.

Fine-needle aspiration of amyloidoma: A critical analysis

BACKGROUND

Amyloid, presenting as a mass, is termed amyloidoma. Among the reported cases, fine-needle aspiration (FNA) of amyloid is often misinterpreted as acellular nondiagnostic material.

METHODS

A computer search of all FNAs was performed and cases diagnosed as amyloidoma were identified.

RESULTS

Among 11,956 cases and 20,634 FNAs, there were six cases and 12 FNAs of amyloidoma. One case with mucin/myxoid matrix was misinterpreted as amyloid, which on our review was Congo red negative. All five other cases of amyloidoma were adequate for evaluation. The smears showed most of the aspirated contents in the middle of the slide and it did not spread when smeared. The amyloid was present as large chunks of waxy, smooth, orangophilic/cyanophilic fragments on Papanicolaou stain and as basophilic fragments on Diff-Quik stain in a clean background. In cases with lymphoma/myeloma, there were admixed lymphocytes and/or plasma cells. Unlike fibrous tissue, amyloid aspirates well and provides adequate material for interpretation. The clean background distinguishes it from mucin/myxoid matrix. Congo red stain was positive with apple green birefringence in all five cases. Further subtyping by mass spectrometry showed AL (κ) type in three patients and AIns (insulin) type in one patient. In one patient with lymphoma, the subtyping was not done.

CONCLUSION

FNA of amyloidoma is rare (0.04%), but an optimal method for diagnosis and subtyping, avoiding unwanted surgical interventions. Although mistaken for fibrous tissue, which aspirates poorly, abundant acellular orangophilic/cyanophilic material on FNA should raise a suspicion for amyloid. Unlike mucin/myxoid matrix, amyloid does not smear the background.

Calcaneal Bone Biopsy Inconsistency between Specimens Obtained From Trephine and Fine Needle Biopsy Techniques

Standardized methods for osteomyelitis (OM) diagnosis of the lower extremity have proven to be difficult. Preoperative probability of foot osteomyelitis necessitates a combination of clinical, laboratory, imaging evidence (i.e., X-ray, CT, MRI), and bone biopsy to guide diagnosis and treatment. In the recent past, the relative weight that clinicians give to these collections of data to advise potential surgical intervention has been challenged, particularly with histologic evaluation of bone biopsy-traditionally considered "gold standard" in OM diagnosis. This study seeks to further expand this dialogue by retrospectively comparing calcaneal bone biopsies performed by direct visualization trephine approach (performed by Surgeons) vs fine needle biopsy with fluoroscopy guidance (performed by Interventional Radiologists). Results obtained from 57 patients with suspected calcaneal osteomyelitis demonstrate that Trephine obtained samples are significantly more likely to produce histopathologic evidence of OM (p-value: .013), microbiologic evidence of OM (p-value: <.001) and have better histopathologic and microbiologic concordance (p-value: <.001) than calcaneal bone biopsies obtained from Fine Needle Biopsy with fluoroscopy guidance.

Parapharyngeal Lymph Node Metastasis From Papillary Thyroid Carcinoma

Metastatic parapharyngeal lymph nodes (LNs) from papillary thyroid carcinomas (PTC) are uncommon and can easily remain undetected. We describe a case that involves a 62-year-old woman treated for a PTC, who presented a rise in serum thyroglobulin (TG) levels. A computed tomography scan was performed, and revealed metastatic nodes in the left parapharyngeal space (PPS). A surgical resection of the nodes was performed with external cervical approach. A histological exam confirmed the diagnosis of a metastatic LN of a PTC. The aim of this report is to emphasize on the possibility of parapharyngeal metastatic nodes in PTC and to describe the diagnosis methods, treatment options, and impact on the prognosis.

PD-L1 expression in fine-needle aspiration cell blocks of head and neck squamous-cell carcinoma and its cytohistological concordance

BACKGROUND

PD-L1 immunoexpression in head and neck squamous-cell carcinoma (HNSCC) determines immunotherapy eligibility. Patients are often diagnosed using fine-needle aspiration (FNA) of metastatic lymph nodes, however, the cytohistologic correlation of the combined positive score (CPS) is largely unknown.

METHODS

This study retrospectively identified 96 paired histologic (HS) and cytologic specimens (CyS), between 2016 and 2020, diagnosed with HNSCC. Cases with <100 tumor cells (n = 54) or missing block(s) (n = 8) were excluded. All 34 case pairs were scored with CPS using the PD-L1 22C3 pharmDx assay at clinically relevant cut-offs of <1%, 1%-19%, and ≥20% independently by three observers blinded to the case pairs (CyS with corresponding HS).

RESULTS

The CPS (<1/1-19/≥20) for CyS and HS were as follows: 10(29.4%)/10(29.4%)/14(41.2%) and 2(5.9%)/13(38.2%)/19(55.9%), respectively. There was fair overall cytohistologic agreement (OA) of 76.5% (k = 0.261) at the CPS cut-off of 1. The OA did not differ significantly between site-matched (n = 13) and -unmatched (n = 21) case pairs (p = .4653). CyS has a specificity and positive predictive value (PPV) of 100% but a negative predictive value (NPV) of only 20% as compared to its paired HS.

CONCLUSIONS

Our study demonstrates fair CPS cytohistologic correlation in HNSCC specimens using the PD-L1 IHC 22C3 pharmDx assay with high PPV but low NPV. This suggest that determining PD-L1 status in FNA specimens can play an important role in the clinical management of HNSCC patients.

Two-tier subclassification of the Bethesda category III (atypia of undetermined significance/follicular lesion of undetermined significance) in thyroid cytology

BACKGROUND

The Bethesda category III, AUS/FLUS, comprises a heterogeneous group of thyroid lesions with variable risk of malignancy (ROM). This study evaluates ROM in two subgroups of this category based on nuclear atypia and architectural atypia.

METHODS

Cases in Bethesda category III were reported based on nuclear atypia (AUS) and architectural atypia (FLUS). ROM was calculated by comparing the cytologic diagnosis to the follow-up histologic diagnosis.

RESULTS

Among the 610 Bethesda category III cases in this study, 306 (50.2%) and 304 (49.8%) cases were reported as AUS and FLUS, respectively. One hundred and eighty six of 306 AUS (60.8%) and 193 of 304 FLUS (63.5%) cases underwent surgical intervention. ROM of the cases in Bethesda category III was 12.8% if all cases were counted and 20.6% if only surgical cases were counted. When analyzing separately, ROM of AUS cases was 17.0% and 28.0% with all cases and surgical cases only, respectively. For FLUS cases, ROM was 8.6% and 13.5% with all cases and surgical cases only, respectively.

CONCLUSION

In Bethesda category III, ROM in the cases with nuclear atypia was significantly higher than the cases with architectural atypia. Sub-classifying the Bethesda Category III cases with nuclear atypia and architectural atypia, respectively may better stratify the ROM.