Faculty Bibliography

INTRODUCTION/BACKGROUND:There is no consensus for interpretation of p16 immunohistochemistry (IHC) in cytology preparations. Our study aims to assess p16 IHC staining in formalin-fixed cytology cell blocks (CBs) from head and neck squamous cell carcinoma (HNSCC) fine-needle aspiration (FNA) specimens in comparison with surgical pathology p16 staining and to determine the reproducibility of p16 IHC scoring in CBs. METHODS:) was calculated to assess inter-rater reliability. RESULTS:= 0.79 (95% CI: 0.61-0.98). CONCLUSION/CONCLUSIONS:p16 IHC performed on cytology CBs can serve as a surrogate marker for the detection of HPV with high sensitivity and specificity levels. Using a threshold lower than that recommended for surgical pathology for the interpretation of p16 positivity may be appropriate for FNA cytology CB preparations. All cytopathologists in our study displayed reproducible high sensitivity and specificity values at the >10% threshold.

Introduction: TERT promoter mutations in thyroid carcinoma suggest worse prognosis based on findings of a small number of studies. Additionally, pathologic features and clinical behavior of indeterminate thyroid nodules (ITN) with TERT promoter mutations remain less studied. Our study aims to explore the clinicopathologic features of ITN with TERT promoter mutations.
Material(s) and Method(s): A search conducted in our electronic medical record between 2015-2018 identified 18 cases with indeterminate thyroid fine-needle aspiration (FNA) cytology (Bethesda Class III, IV, and V) and a TERT mutation on molecular testing. 17 patients underwent thyroidectomy and were the subjects of this study.
Result(s): The mean age was 65 (range 38-83) with a female to male ratio of 9:8. The FNA Bethesda diagnoses were Class III in 9, IV in 8, and V in 1. Majority of patients who underwent thyroidectomy had malignant nodules (14,78%). Thyroidectomy diagnoses included classic PTC (5,29%), FVPTC (5,29%), follicular variant of papillary carcinoma (3,17%), poorly differentiated thyroid carcinoma (1, 6%), follicular adenoma (2,11%) and NIFTP (1,6%). Additional alterations were present in 11 cases, including NRAS(6), KRAS(2), and BRAF V600E (3). Of three cases with concurrent BRAF V600E mutation, two were metastatic, and one had tall cell features. Of two follicular adenoma cases, one had a concomitant NRAS mutation, and the other displayed negative results on Afirma testing. Malignant cases tended to occur in older patients, the majority exhibited follicular architecture, frequent oncocytic morphology, and higher pathologic stage (pT3 in 92%, pT2 in 8%).
Conclusion(s): Most TERT promoter mutations in ITN cytology are associated with high risk of malignancy and these malignancies are associated with unfavorable features such as advanced stage, capsular/vascular invasion, and metastatic disease. Few TERT promoter mutations have a benign outcome. Further studies on ITNs with TERT mutations are needed to determine the optimal management of these nodules.
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Introduction: The Paris System classifies polyoma virus cytopathic effect (P-CPE) as "negative for high grade urothelial carcinoma (HGUC)". However, P-CPE may raise false suspicion for HGUC. Conversely, HGUC cells may display considerable degenerative nuclear changes mimicking P-CPE. Thus, P-CPE remains a known source of "atypia" in urine cytology. The aim of our study was to determine the frequency of P-CPE cases reported as atypical urothelial cells (AUC) in our laboratory, and to assess the diagnostic utility of SV40 immunostaining (IHC) in this setting.
Material(s) and Method(s): Urine cytology cases, all processed as single Thin prep (TP) slides, were searched for P-CPE diagnosis from 2018 to 2020. An additional slide was prepared for a subset of 40 randomly selected cases (19 P-CPEs, 21 negative controls) for SV40 IHC validation on TP slides.
Result(s): There were 111 urines with P-CPE. 51% were included in this study (Figure 1). Of these, 25% were diagnosed as negative for HGUC, 72% as AUC, and 3% as suspicious for HGUC. Follow-up histology showed HGUC in 3 (5%) cases (2 with AUC and 1 with suspicious for HGUC presurgical cytology). SV40 IHC was positive in 61.5% of cases in the P-CPE group and negative in 38.5% including one with confirmed HGUC on biopsy (Figure 2). In the control group, SV40 IHC was negative in 88% and equivocal in 12% (Figure 3). The difference in SV40 IHC between the P-CPE and control group was statistically significant (p<0.001).
Conclusion(s): Majority of urine samples with P-CPE were reported as AUC with a very low incidence of confirmed HGUC. SV40 IHC aided in the confirmation of viral infection. Our study shows that once the source of atypia is confirmed as polyoma virus with SV40 IHC, downgrading atypia to negative can safely be accomplished without the concern for missing a high-grade lesion. [Formula presented] [Formula presented] [Formula presented]
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Introduction: Our study aimed to assess the sensitivity (SN) and specificity (SP) of fluorescence-in-situ-hybridization (FISH) alone and as an adjunct to routine cytology for the detection of malignancy in biliary tract lesions.
Material(s) and Method(s): Bile duct brush specimens with FISH results from 1/2013-1/2020 were tabulated yielding 55 cases. Cases were classified as "Benign" where surgical resection showed benign findings or follow-up was uneventful >18 months and as "Malignant" where surgical pathology or clinical follow up identified malignancy in the pancreatobillary system (40 cases). Cases not falling under these categories were excluded. Cytologically suspicious and positive cases were designated as "positive." FISH positive and "equivocal" results were also designated as "positive." When examining the combined cytology-FISH results, cases were designated as "positive" if either cytology or FISH test was "positive." Atypical cytology cases were excluded.
Result(s): 21/40 cases fell under benign or malignant categories. 5/21 cases had malignant surgical follow-up: 4 pancreaticobiliary ductal adenocarcinoma and 1 Hodgkin lymphoma. FISH showed high SP (100%) and low SN (33.3%) in diagnosing malignancy in bile brush cytology. In cytology alone, FISH alone and the combined cytology-FISH testing, there was a statistically significant difference in risk-of-malignancy between Positive and Negative diagnostic categories, p<0.05(Table 1). Accuracy improved using combined cytology-FISH results over either test alone, area under the curve (AUC: Cytology=0.8; FISH=0.717; Combined test=0.85) (Figure1).
Conclusion(s): Cytology, FISH and combined cytology-FISH results all showed higher risk-of-malignancy values in positive compared to negative categories. The FISH-cytology combination may improve the SN of detecting malignancy in biliary tract lesions. Sample size may have been too small to detect a significant difference between combined cytology-FISH results versus either test alone. However, due to the potential clinical impact of improving bile duct brush cytology accuracy, our results should be evaluated further in larger samples. [Formula presented] [Formula presented]
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Introduction: Pancreatic neuroendocrine tumors (PNET) are relatively uncommon neoplasms. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been shown to be an efficient method for preoperative assessment of pancreatic tumors; however, the role of cytologic grading of PNETs is unclear. We aim to evaluate cytologic diagnosis and grading of PNETs by correlating with histopathology.
Material(s) and Method(s): Cytopathology cases with a diagnosis of PNET from 6/2011-6/2020 were tabulated and compared with their corresponding surgical pathology to evaluate the diagnostic accuracy of EUS-FNA. In addition, tumor grading based on Ki-67 immunohistochemistry was correlated between cytologic and histologic specimens (Cohen's kappa coefficient).
Result(s): Thirty-nine cases of EUS-FNAs with PNET diagnosis and concomitant histologic evaluation were included. EUS-FNA showed a positive predictive value of 85% for PNET diagnosis. There were 6 discrepant cases (15%), including: 1 mixed ductal-neuroendocrine carcinoma, 1 PNET with concomitant high-grade carcinoma, 1 metastatic renal cell carcinoma, 1 solid pseudopapillary neoplasm, and 2 cases of chronic pancreatitis, potentially explained by under-sampling, scant cellularity and/or absence of adequate cell block for immunostaining (Table 1).Nineteen cases had Ki-67 immunostaining on both cytologic and histologic specimens with a concordance of 58% (Table 2). All discrepancies in Ki-67 evaluation were due to underscoring in cytologic samples. Cyto-histologic grading correlation was fair (Cohen's Kappa coefficient=0.24).
Conclusion(s): EUS-FNA is a valuable minimally invasive diagnostic tool in the preoperative diagnosis of PNETs with a positive predictive value of 85% in this cohort. Cyto-histologic grading correlation was fair, which suggests that applying surgical pathology ki-67 grading cut-off points to cytology sample evaluations may not be appropriate. All cyto-histologic grading discrepancies in our study were due to underscoring in cytologic samples, which might be related to sampling issues or tumor heterogeneity.
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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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Introduction: SARS-CoV-2 (COVID-19) is known to cause severe respiratory infections with occasional accompanying pleural (PE), pericardial (PCE) or peritoneal effusion (PTE). The effect of COVID-19 disease on effusion cytology is not yet known. Therefore, our study aims to examine the cytomorphologic features and work-up of effusion fluid in patients in recovery from COVID-19 infection versus those with active disease.
Material(s) and Method(s): PE (n=15), PCE (n=1), PTE (n=19) samples from hospitalized patients with COVID-19 infection (6/1/2020-12/30/2020) were reviewed. EFs with metastatic carcinoma were excluded. Differential cell count (DCC), cytomorphology, and immunostains of EFs were retrospectively evaluated by a board-certified cytopathologist and compared between patients with active infection (AI, n=22, positive COVID-19 nucleic acid amplification test (NAAT) within 2 months) and recovery phase from COVID-19 (RC, n=13, negative COVID-19 NAAT for >2 months).
Result(s): Cytology diagnoses were: negative for malignancy (n=30), atypical (n=4), suspicious for malignancy (n=1). AI cases showed more atypical mesothelial cells than RC cases (Table 1, p<0.05), some with enlarged nuclei with prominent nucleoli and occasional multi-nucleation (Figure 1), and some with bizarre nuclei (Table 1, p<0.01). Immunostains were performed more often in AI than RC cases (50.0% vs 7.7%, p<0.05). DCC (available in 28 cases) showed no significant difference amongst AI and RC cases (Figure 1, p>0.05).
Conclusion(s): Our study found atypical and bizarre mesothelial cells to be present more often in effusions of cases with active COVID-19 infection than in samples from patients in recovery, though DCCs did not show significant difference. Diagnosis of malignancy may be considered in cases with such nuclear atypia, which explains increased immunostain work-up in AI cases. It is important for cytopathologists to consider the patients' COVID-19 infection status when evaluating effusion cytology cases. [Formula presented] [Formula presented] [Formula presented]
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Background: Thyroseq next-generation sequencing assay and Afirma gene expression classifier (GEC) are used to risk-stratify thyroid nodules with indeterminate cytology: Bethesda III (atypia of undetermined significance, AUS/FLUS) and IV (suspicious for follicular neoplasm, SFN). In this study, we performed a paired comparison of both tests on the same group of indeterminate thyroid nodules with surgical followup.
Design(s): Of 645 AUS/FLUS/SFN cases with both molecular testing and surgical resection in 2014-2017, 40 cases had both Thyroseq (v2) and Afirma GEC performed on the same specimen. Cross-tabulations and ROC curves were created. McNemar tests were done to compare the performance of Thyroseq versus Afirma. The diagnostic performance of combined results were also examined: the combined result was called positive only if both Thyroseq and Afirma were positive/suspicious. Non-invasive follicular thyroid with papillary like nuclear features (NIFTP) on surgical resections was defined as ?positive.? Results: 20/40 (50%) cases were ?positive? on surgical pathology: 8 papillary thyroid carcinoma (PTC), 11 NIFTP, and 1 follicular carcinoma. Thyroseq and Afirma both showed high sensitivity and low specificity in diagnosing malignancy in indeterminate thyroid nodules. Next, the results of both tests were combined. The overall accuracy of combined testing was higher than either test alone (Figure 1). Compared to Afirma alone, the combined test had significantly higher specificity (30% vs 70%, p<0.05, Table 1), while the sensitivity declined from 90% to 75% (p=0.25, Table 1). Compared to Thyroseq alone, there was no significant difference in specificity (45% vs 70% p=0.06) or sensitivity (80% vs 75%, p=1.00, Table 1). Positive predictive value (PPV) improved compared to either test alone. Negative predictive value (NPV) improved compared to Thyroseq alone, and declined only slightly compared to Afirma alone.
Conclusion(s): Molecular testing of cytologically indeterminate thyroid nodules helps determine the extent of surgery. Low diagnostic performance metrics may limit the utility of molecular studies in distinguishing benign from malignant thyroid lesions. Our results show that the combined results of Thyroseq and Afirma improved the specificity and overall accuracy of molecular testing, and provided additional value in the surgical management of patients with indeterminate thyroid nodules. To the best of our knowledge, this is the first study that compares the performance of these two molecular tests on the same thyroid nodules