Faculty Bibliography

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: 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: 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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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

Background: Fine needle aspiration (FNA) of salivary gland lesions is a fast, minimally invasive and cost-effective procedure that aids in early patient management decisions. Recently, the Milan System for reporting Salivary Gland cytopathology (MSRSGC) was published in order to establish diagnostic categories with implied malignancy risks and recommended clinical follow-up. Our study aims to assess the interobserver reproducibility of salivary gland cytology diagnoses using the MSRSGC.
Design(s): Salivary gland cytology slides from 101 cases with surgical pathology follow-up from 11/2016-06/2019 were blindly and independently reviewed and classified according to the MSRSGC by four cytopathologists. Unweighted and linearly weighted percent agreement and Gwet's AC1 coefficients were calculated in AgreeStat 2015.6/Windows (AgreeStat Analytics).
Result(s): Unweighted percent agreement was 0.69 (substantial agreement) and weighted percent agreement was 0.92 (almost perfect agreement). Unweighted Gwet's AC1 was 0.64 (substantial agreement), and weighted Gwet's AC1 was 0.84 (almost perfect agreement) (Table 1). 50 of 101 (49%) cases had complete agreement among all 4 observers, 77 (76%) had at least 3 observers agreeing on the same diagnosis, and 99 (98%) had at least 2 observers agreeing on the same diagnosis. Category IVA (benign neoplasm) was the most likely to show interobserver agreement: among the 51 cases in which at least 2 cytopathologists agreed on a diagnosis of category IVA, 34 (67%) showed complete agreement among all 4 cytopathologists. Two cases showed no agreement among any observers. One low-grade mucoepidermoid carcinoma had MSRSGC diagnoses ranging from I to IVB, and one secretory carcinoma had MSRSGC diagnoses ranging from III to VI. Low-grade mucoepidermoid carcinoma is reportedly the most common malignant salivary gland tumor associated with false-negative diagnoses on cytology and is often misdiagnosed as a pleomorphic adenoma, due to the presence of bland-appearing intermediate cells as well as confusion between mucin and chondromyxoid stroma (Figure 1). The case of secretory carcinoma showed scant cellularity on cytology, confounding an accurate diagnosis (Figure 2).
Conclusion(s): Interobserver reliability analyses using the MSRSGC showed substantial to almost perfect agreement among the four observers in our study. Only two cases showed no agreement. Category IVA (benign neoplasm) is the most likely to show complete agreement among all observers

Background: The ASCCP management guidelines recommend that women with an unsatisfactory Pap test (UPT) and negative HPV co-test 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 co-tested, 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 co-test result is predictive of the absence of a high grade squamous intraepithelial lesion (HGSIL) and whether these patients may be called back for repeat testing at an interval longer than 2-4 months.
Design(s): Follow up cervical cytology and biopsy results in women with UPT and HPV co-tests between 2017-2019 were collected. Original UPT and HPV co-test results were correlated with follow up Pap and biopsy results.
Result(s): There were 708 UPT cases out of 30,647 total Pap tests (2.3%). Among the 708 UPT cases, 407 had HPV co-testing (57%); 260 (37%) were followed by repeat Pap or biopsy within 2-4 months and 317 (45%) within 12 months. The total follow-up rate was 81%, with a range of 10 days to 18 months. Table 1 depicts follow up information for women with UPT and HPV co-testing. Negative predict values of HPV co-testing for LGSIL and HGSIL detection were 98% and 100%, respectively, while positive predictive values were 43% and 4.7%.
Conclusion(s): A negative HPV co-test in women with an UPT predicted the lack of HGSIL in our study. Compliance with the recommended follow up time of 2-4 months for women with UPT was low at 37%. This may be due to multiple factors, one presumably being the women's reluctance to undergo a repeat pelvic exam due to its uncomfortable nature. Even with a longer follow up time of up to 12 months, there were no HGSILs in the HPV negative group. Our study suggests that women with an UPT and a negative HPV co-test may be safely called back at an interval longer than 2-4 months

Introduction: In urine cytology, the atypical category suffers from interobserver variability and a wide range of risk of malignancy (ROM). This leads to confusion and inconsistent clinical management of patients with atypical urine diagnoses. Our study identified the rate of atypical diagnoses at our institution over a five-year period and examined the concurrent or follow-up surgical pathology diagnoses (SD) to understand the clinical significance of atypical urine specimens.
Material(s) and Method(s): A retrospective review of adult urine cytology specimens pre- 7/1/2014-6/30/2016 (TD) and post- 7/1/2017-6/30/2019 (TPS) implementation of the Paris System for Reporting Urinary Cytology was performed, which identified 10,132 total urine specimens. Of these, 2,457 specimens from 1,727 patients were categorized as "atypical." 177 cytology specimens were found to have corresponding urinary tract SD within 90 days. Pre- and post-Paris System (TD and TPS) urine cytology diagnoses were compared.
Result(s): The overall rate of "atypical" diagnoses was 2,457/10,132 (24.3%). 177 of 2,457 atypical specimens (7.2%) had corresponding urinary tract SD, of which the ROM was 37.9% (TD 37.8%, TPS 37.9%, p=0.992). 61 of 177 atypical urines (34.5%) were high grade (HGUC/CIS) on SD (TD 32.9%, TPS 35.8%). 66 of 177 atypical urines (37.3%) were low grade urothelial neoplasms (LGUNs), atypical, or dysplastic on SD (TD 39.0%, TPS 35.8%, p=0.660). 44 of 177 atypical urines (24.9%) were benign on SD (TD 23.2%, TPS 26.3%) (Table 1).
Conclusion(s): While the atypical diagnosis rate of nearly 1 in 4 urines is fairly high, over one-third of atypical results signified a high grade malignancy, and over an additional one-third of atypical urines represented LGUN, atypical, or dysplastic surgical pathology diagnoses. These findings emphasize the need for close follow-up in patients with atypical diagnoses on urine cytology. Our findings did not show a significant difference between pre and post TPS follow up data. [Formula presented]
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Introduction: Recent studies evaluating p16 immunohistochemistry (IHC) in cell blocks (CB) of fine needle aspirations (FNAs) in patients with oropharyngeal squamous cell carcinoma (OP-SCC) have shown good correlation between cytology and surgical pathology. Our study aimed to determine the reproducibility of p16 IHC scoring in CBs. Additionally, we evaluated whether interobserver variability would significantly affect the optimal threshold for p16 IHC positivity in CBs.
Material(s) and Method(s): 40 FNAs from 2014-2019 of head and neck squamous cell carcinoma with p16 IHC were obtained. Surgical pathology p16 IHC results were set as reference. p16 IHC stained CBs were scored independently by 5 cytopathologists and recorded as percentage of tumor cell positivity: 0%,0-1%,1-10%,10-50%,50-70%,70%. AgreeStat2015.6/Windows software was used to calculate the percent agreement (Pa) and Gwet's AC1 statistic to assess inter-rater reliability. ROC curves were examined to determine optimal cutoffs for each pathologist based on sensitivity and specificity values (IBM SPSS version 25).
Result(s): Overall performances of the raters were similar, with areas under the curve (AUCs) ranging from 0.88-0.95 (Figure 1). >10% appeared to be the optimal threshold for p16 positivity because this was the lowest threshold to reach 100% specificity with high sensitivity (55-84%) in all 5 raters. Using the >10% as threshold, the Pa was 86% (95% CI 0.78-0.94) and Gwet's AC1 coefficient was 0.72 (95% CI 0.56-0.89).
Conclusion(s): While the goal in developing guidelines for the interpretation of p16 IHC on cytology CBs is to provide generalizable standards for all cytopathologists, interobserver variability must be taken into account. Prior studies have shown optimal cutoffs ranging from >0% (any staining) to >70%, with sensitivity and specificity values ranging from 37%-100%. While our study did not show perfect agreement, all cytopathologists in our study displayed reproducible high sensitivity and specificity values at the >10% threshold with a percent agreement of 86%. [Formula presented]
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