Faculty Bibliography

This study presents two cases of lipid-rich pancreatic neuroendocrine tumors (PanNETs), a rare variant posing significant diagnostic challenges in fine needle aspiration (FNA) cytology and small biopsies. The first case involves an elderly male with a pancreatic tumor, displaying distinct cytoplasmic vacuoles, while the second case is a middle-aged male present with a pancreatic tail mass exhibiting foamy cytoplasm and eccentric nuclei, infiltrating in the stroma. Both cases did not exhibit typical morphologic features of PanNET but demonstrated cytomorphologic features and infiltrative growth patterns that mimicked adenocarcinoma. Further work-up demonstrated that both tumors were immunoreactive for synaptophysin and chromogranin, and were interpreted as well-differentiated, PanNET, lipid-rich variant. The study highlights the overlapping morphological features between lipid-rich PanNETs and other pancreatic neoplasms and underscores the importance of comprehensive cytological and immunohistochemical analysis for accurately diagnosing this variant, particularly due to the risk of misinterpreting it as pancreatic adenocarcinoma. Recognizing lipid-rich PanNETs is crucial for appropriate clinical management, as their identification can significantly impact treatment decisions and patient outcomes.

OBJECTIVES/OBJECTIVE:The 2019 American Society of Colposcopy and Cervical Pathology management guidelines recommend that patients with an unsatisfactory Papanicolaou (Pap) test (UPT) and negative human papillomavirus (HPV) cotest undergo repeat age-based screening in 2 to 4 months. The rationale is that a negative HPV test in the setting of an UPT may reflect an inadequate sample and therefore should not be interpreted as truly "negative." For patients 25 years and older who are cotested, if HPV is positive for the 16 or 18 genotypes, direct referral for colposcopy is recommended. Our study aimed to determine if a negative HPV cotest result is predictive of the absence of a high-grade squamous intraepithelial lesion (HSIL) and whether these patients may be called back for repeat testing at an interval longer than 2 to 4 months. METHODS:Follow-up cervical cytology and biopsy results in women with UPT and HPV cotests from January 2017 to December 2021 were collected. Original UPT and HPV cotest results were correlated with the follow-up Pap and biopsy results. RESULTS:There were 1,496 (2.28%) UPT cases out of 65,641 total Pap tests. Among the 1,496 UPT cases, 1,010 (67.5%) had HPV cotesting; 676 (45.1%) were followed by repeat Pap or biopsy within 4 months and 850 (56.8%) within 12 months. The total follow-up rate was 81%, with a range of 3 days to 36 months. The HSIL rate in HPV-positive cases was 5.7% (3/53) vs 0.4% (2/539) (P = .006) in HPV-negative cases. In UPT, HPV cotesting showed negative predictive values for low-grade and high-grade squamous intraepithelial lesion detection of 98.5% and 99.6%, respectively, while positive predictive values were 19% and 5.7%. CONCLUSIONS:A negative HPV cotest in individuals with UPT predicted the lack of HSIL in our study. Compliance with the recommended follow-up time of 2 to 4 months for women with UPT was low (45.1%). Our study suggests that women with UPT and negative HPV cotest may be safely called back at an interval longer than 4 months.

Introduction: The utility of The Paris System (TPS) in diagnosing low-grade urothelial neoplasm (LGUN) on urine cytology is controversial due to the strict requirement for fibrovascular cores, and low sensitivity/specificity. Many LGUNs are classified as atypical urothelial cells (AUC) on cytology, which compromises the performance and utility of TPS. Here, we studied cytomorphologic features of LGUN in urine samples to determine which features were commonly observed.
Material(s) and Method(s): Twenty-two urine cytology cases with corresponding (within 2 months) LGUN histologic diagnosis were retrieved for this pilot study and were evaluated by one cytopathologist for the presence of clusters, cercariform cells, hyperchromasia, irregular nuclear rim, papillary architecture +/-fibrovascular core, and nucleus:cytoplasm (N:C) ratio (Figure 1). Hierarchical cluster analysis (Ward's Method) was used to classify the features.
Result(s): Of the 22 urines, one was voided (4.5%) and 21 were instrumented (95.5%). Majority (77.3%) were diagnosed as AUC, 1 was suspicious for urothelial carcinoma (4.5%), 4 cases were graded as LGUN (18.2%, Table 1). Clustering analysis demonstrated that the morphologic features abundantly present in the urine specimen of LGUN included: clusters (77.3%), N:C ratio >50% (85.4%), and papillary architecture without a core (72.7%). The features that were mostly absent in LGUN specimens included: irregular nuclear rim (0%), papillary formation with a core (0%), hyperchromasia (9.1%), coarse chromatin (22.7%), and cercariform cells (36.3%). (Table 2).
Conclusion(s): Papillary formation with a fibrovascular core, the most convincing feature of LGUN, was not present in our pilot cohort of LGUN urines. However, our study describes additional cytomorphologic features that may be useful in identifying LGUN in urine cytology. Our research will continue with the evaluation of a larger cohort of LGUN cases with corresponding urine cytology in order to further investigate these findings

INTRODUCTION/BACKGROUND:The American College of Radiology (ACR) Thyroid Imaging Reporting and Data Systems (TI-RADS) was developed to standardize thyroid ultrasound reports and predict the likelihood of malignancy. In our study, we aimed to correlate indeterminate thyroid fine needle aspiration cytology cases with preceding ultrasound (US) ACR TI-RADS scores and concurrent molecular testing results to examine how well the use of the ACR TI-RADS in our institution predicted which patients with indeterminate cytology might harbor molecular alterations. MATERIALS AND METHODS/METHODS:We performed a retrospective review of thyroid nodules. Patients with US reports that included TI-RADS scores, fine needle aspiration specimens with indeterminate cytology (Bethesda class III-V), and molecular testing results were included. RESULTS:A total of 46 indeterminate cytology cases had had preceding US reports with TI-RADS scores and molecular testing (Bethesda class III, n = 37; Bethesda class IV, n = 6; Bethesda class V, n = 3). Most of the indeterminate cases had had a TI-RADS score of TR4 (31 of 46; 67.39%) or TR5 (9 of 46; 19.57%). RAS mutations were the most common alteration (n = 12). Of the 46 cases, 22 (47.85%) showed no alterations. Ten cases proceeded to surgery, of which seven displayed malignancies. CONCLUSIONS:Molecular testing in cytologically indeterminate thyroid nodules provided valuable information for TR4 and TR5 lesions; however, the TR2 and TR3 lesions often had no molecular alterations. These findings highlight the potential value of including US imaging features when assessing the significance of indeterminate cytology findings.

Follicular dendritic cell sarcomas (FDCS) are rare tumours of lymph nodes and extranodal tissues which are grouped with the histiocytic and dendritic cell neoplasms. The diagnosis is usually made after thorough clinical and pathological examination with immunohistochemical analysis. Difficulties persist in diagnosing FDCS on cytological preparations. We report herein a case of a 57-year-old female who presented with a right neck mass of 5 months duration. Computed Tomography (CT) imaging of the neck reported a necrotic right level IIb lymph node and asymmetric fullness of the right palatine tonsil. Fine needle aspiration (FNA) biopsy revealed numerous spindle, oval and stellate neoplastic cells, arranged singly and in syncytia with moderate nuclear pleomorphism, vesicular chromatin pattern, and prominent nucleoli, sprinkled with small lymphocytes. The tumour cells were strongly diffusely positive for CD21, CD23, and D2-40 immunostaining on cell bock sections, but were negative for CD1a and CD34, supporting the diagnosis of FDCS. Follow-up surgical pathology on the resection showed histopathological features and an immunohistochemical profile consistent with FDCS.

Introduction: Preoperative diagnosis of pancreas ductal adenocarcinoma (PDAC) on endoscopic ultrasound guided fine needle aspiration (FNA) cytology is often required to determine proper therapy. Accurate cytopathology diagnosis on FNA may be challenging due to limited/suboptimal cellularity and gastrointestinal contamination with accurate diagnoses necessitating consideration of the full clinical and radiologic picture in evaluating the pancreatic lesions. In this study, we investigated predictive value of integrating cytology diagnosis, radiologic and clinical features in diagnosing pancreatic adenocarcinoma.
Material(s) and Method(s): Pancreatic FNA cases from 1/2016-12/2018 with >18 months of follow-up or histopathology diagnosis on surgical resection were retrieved (n=203). Cases were categorized as "Adenocarcinoma" or "Benign" according to the surgical resection pathology or clinical follow-up. Their documented serum CA19-9 level, and in-house radiologic reports were studied (n=177, Table 1). A multiplayer perceptron neural network (MNN) was trained and tested for the ability of using the integrated clinical and radiologic features and cytologic diagnosis to distinguish between benign and malignant cases.
Result(s): The sensitivity, specificity, and accuracy for pancreatic FNA cytology alone was 77.5%, 97.6%, and 88.4%, respectively. There were significant correlations between malignant outcome and cytology diagnosis, CA19-9 level and involvement of common bile duct (CBD), pancreatic duct (PD), superior mesenteric artery (SMA) or superior mesenteric vein (SMV) (Table 1, p<0.001). Integration of the cytology diagnosis and CA19-9 level showed 92% accuracy in predicting surgical outcome. The MNN highlighted cytopathology to be the most important factor in predicting pancreatic lesion outcomes, followed by the serum CA19-9 level and involvement of the SMA (Figure 1).
Conclusion(s): Integration of the clinical and radiologic information with cytology diagnosis can improve accuracy in evaluating pancreatic adenocarcinomas, especially in suboptimal FNA cytology specimens. [Formula presented] [Formula presented]
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