Faculty Bibliography

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: 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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Background: The American College of Radiology (ACR) 2017 Thyroid Imaging Reporting and Data System (TI-RADS) added a new risk stratification system for classifying thyroid nodules based on sonographic appearance (T1-T5). FNA is generally not recommended for benign or low suspicion nodules. However, other factors such as nodule size and family history may trigger an order for an FNA. Our study aimed to examine the cytologic diagnosis, molecular profiles and surgical follow up in a select group of patients with sonographically benign appearing thyroid nodules.
Design(s): We performed a retrospective review in our pathology database of cases from 1/1/2016-4/1/2018, prior to our institution's adoption of the TI-RADS classification system. Thyroid nodules with in-house ultrasound exam (US), FNA cytology, The Bethesda System (TBS) cytology diagnosis, molecular testing, and surgery were included. The USs from these cases were retrospectively reviewed and assigned TI-RADS scores (TR1-TR5) by a board certified radiologist. There were no TR1 nodules. TR2 (not suspicious) and TR3 (mildly suspicious) nodules were selected for evaluation.
Result(s): From 1/1/2016-4/1/2018, there were a total of 34 patients that fit the selection criteria. Of these, there were 5 TR2 thyroid nodules and 29 TR3 thyroid nodules with corresponding FNA TBS, molecular and surgical diagnoses (table1). (Table presented)
Conclusion(s): Our study shows that sonographically benign appearing/low suspicion thyroid nodules may display molecular alterations; 50% of those proved to be RAS mutations in our study. Approximately 60% of aspirated TR2 nodules and 66% of TR3 nodules were malignant or NIFTP on excision. Despite their lower suspicion index on US, with lower TI-RADS scores, benign appearing nodules on US need to be evaluated in the context of clinical, cytologic and molecular information in order to determine clinical course

Background: Salivary gland neoplasms are rare and the majority are benign with only 20% displaying malignancy. Fine needle aspiration (FNA) plays an essential role in the initial evaluation of salivary gland lesions by providing a pre-operative diagnosis to determine appropriate management. Recently, a tiered classification system known as the Milan System for reporting Salivary Gland cytopathology (MSRSGC) has been published. This system formalizes diagnostic categories with related malignancy risk, recommended clinical therapy and follow-up. Our study aims to compare sensitivity, specificity and risk of malignancy (ROM) between the MSRSGC and the original FNA cytology diagnostic categories used at our institution to determine if the MSRSGC offers added benefit.
Design(s): Salivary gland cytology slides from subjects with final surgical pathology resections from 11/2016-06/2019 were blindly reviewed and classified according to the MSRSGC. MSRSGC diagnoses were correlated with surgical pathology diagnoses and compared to the original cytology diagnostic categories. Sensitivity, specificity and ROM of diagnostic categories were calculated for both systems.
Result(s): Follow-up histopathology was available for 101 patients with salivary gland lesions. The MSRSGC had a sensitivity of 69.0% and a specificity of 92.9%. The original classification system had a sensitivity of 75.0% and a specificity of 89.9%. ROM for MSRSGC categories and original diagnostic categories are given in Table 1 and listed side by side to reflect distribution of cases in each system. (Table presented)
Conclusion(s): Performance of the MSRSGC was comparable to that of the original classification system in the majority of cases. Both systems had a similar sensitivity, specificity and ROM in the equivalent categories. The single "non-diagnostic" and the three "nonneoplastic" cases under MSRSGC that showed histopathologic evidence of malignancy were called "negative for malignancy" in the original classification showing lack of cytohistologic correlation for both systems due to sampling errors. Two of the three cases classified as "atypia of undetermined significance" under the MSRSGC were originally classified as "negative for malignancy". Our findings suggest that traditional diagnostic classification methods for salivary gland cytopathology already established at an institution can perform as well as the MSRSGC in relaying the appropriate diagnostic information, undermining the need for transition to a new classification system

Background: HPV-related oropharyngeal squamous cell carcinoma (OP-SCC) has a superior prognosis and response to therapy than that of conventional head-and neck SCC (HNSCC). The College of American Pathologists (CAP) guidelines recommend that P16 immunostaining (IHC) in >70% of tumor cells is an excellent surrogate marker for HPV in surgical pathology OP-SCC. Fine needle aspiration (FNA) cytology is an ideal method for obtaining diagnostic material for OP-SCC and may represent the only attainable specimen. However, there is no consensus for interpretation of P16 IHC result in cytology preparations. Our study aims to assess OP-SCC P16 staining in cell block cytology preparations in comparison with P16 staining on surgical pathology specimens.
Design(s): FNA specimens from 2014-2019 of OP-SCC with P16 IHC staining were obtained. Surgical pathology P16 IHC results were set as the gold standard. Cytology cell block tumor cellularity (<100 vs >100 cells) and P16 percentage of tumor cell positivity (0%, 1-10%, 11- 50%, 51-70%, and >70%) were recorded. Using different threshold levels of P16 tumor cell positivity in cell blocks as compared with surgical P16 IHC results, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated.
Result(s): 40 matched FNA neck lymph node/mass cytology and surgical cases were identified. Sensitivities and specificities varied when thresholds changed, with sensitivities and specificities ranging from 93.5% and 66.7% (respectively) when any P16 positivity is seen (>0%), to 56.7% and 100% (respectively) when P16 positive threshold is set at >70% (table 1 and figure 1). <100 and >100 tumor cells were seen in 11 and 29 cases respectively. (Table presented)
Conclusion(s): Our study shows that P16 IHC performed on cytology cell blocks can serve as a surrogate marker for the detection of HPV, similar to P16 staining in surgical pathology, with high sensitivity and specificity levels. The challenge in cytology specimens is choosing the proper threshold to balance between the optimal sensitivity and specificity. Our data suggests that using a threshold lower than that of surgical pathology (70%) for p16 positivity may be appropriate for FNA specimens, as lower thresholds displayed increased sensitivities with only moderately lower specificities. Of note out of the 11 cases with <100 tumor cells, only one cases was a false negative, indicating that tumor cellularity may not affect P16 interpretation on cell block

BACKGROUND:Differentiating parathyroid from thyroid lesions can be difficult on fine-needle aspiration (FNA) due to overlapping cytomorphologic features. While the traditional parathyroid hormone (PTH) assays can help in the distinction, these tests may be cumbersome, particularly when the lesion is unexpected clinically and a needle wash is not collected at the time of FNA. Therefore, we chose to investigate the application of immunohistochemical staining (IHC) with GATA 3 and thyroid transcription factor-1 (TTF-1) on air-dried cytology smears to distinguish parathyroid and thyroid lesions. METHODS:Air-dried touch preparation (TP) slides were prepared from consecutively selected parathyroid and thyroid specimens. Thirteen FNA cases with the clinical concern for parathyroid lesions were also included in the study. IHC was performed on unstained and ultrafast Papanicolaou (UFP) stained air-dried slides. RESULTS:On TP slides, GATA 3 expression was observed in all cases of parathyroid origin but no immunoreactivity was present in thyroid lesions. TTF-1 expression was observed in all cases of thyroid origin but not in parathyroid lesions. GATA 3 and TTF-1 expression of 13 FNA cases were consistent with the clinical impression or concurrent PTH tests. CONCLUSIONS:IHC with GATA 3 and TTF-1 on air-dried cytology smears is a simple and effective way to differentiate parathyroid vs thyroid lesions on FNA. Air-dried unstained and UFP-stained slides perform equally well with IHC, but UFP-stained slides provide the added benefit of morphologic evaluation and assessment of smear cellularity prior to IHC.

Introduction: The Thyroid Imaging Reporting and Data System (TI-RADS) was designed to standardize risk stratification of thyroid nodules by ultrasonographic criteria and categorize nodules as TR1-TR5 to designate nodules for fine needle aspiration (FNA) or surveillance. Thyroid FNAs are classified according to The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) (categories TBS I-VI) with an associated risk of malignancy and management guideline. We utilize Thyroseq-V3 molecular testing for indeterminate cytology cases (TBS III- V). Our aim was to correlate indeterminate thyroid FNAs with TI-RADS scores and molecular results to determine if TI-RADS is accurately identifying nodules for biopsy.
Material(s) and Method(s): A retrospective review of thyroid nodules from 1/1/2018-8/30/2018 was performed. Patients with ultrasound (US) reports including TI-RADS scores, FNA reports with indeterminate cytology (TBS-III, TBS-IV and TBS-V) and molecular testing were included.
Result(s): 370 of 1000 thyroid nodules had US reports with TI-RADS scoring and concurrent cytology. 47 cases had indeterminate cytology (TBS-III n=37, TBS-IV n=7 and TBS-V n=3) and reflex molecular testing. Majority were TR4 (31/47;65.97%) and TR5 (10/47;21.27%) (Table1). 23/47 (48.94%) showed no alteration. NRAS was the most common alteration (8 cases), followed by Copy Number Alterations (CNA) (6 cases) (Figure 1). Three TBS-III cases showed dual alterations (NRAS/CNA x2 and HRAS/CNA). Two TBS-IV cases had multiple alterations (EIF1AX/NRAS/TP53 and NRAS/PTEN).
Conclusion(s): While majority of thyroid nodules had a high TI-RADS score (TR4 or TR5), most cases fell into the atypical category (TBS III). Almost half of the thyroid nodules lacked any molecular alterations thereby suggesting an over-classification by TI-RADS. Further refinement of the TI-RADS criteria may be warranted. [Figure presented] [Figure presented]
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Objective: Squamous intraepithelial lesions (SILs) are classified as low-grade SIL (LGSIL) and high-grade SIL (HGSIL). 'LGSIL cannot exclude high grade' (LGSIL-H) interpretive category has been used in cases where findings exceed criteria for LGSIL, but do not fulfill the criteria for HGSIL. This study analyzed follow-up histology of LGSIL-H cases and compared the follow-up results of LGSIL-H with LGSIL to determine the utility of LGSIL-H category using a single institution's experience. Study Design: Pap smears with LGSIL-H interpretation from 2005 to 2008 were retrieved. Histological follow-up results for LGSIL-H cases were analyzed and compared to the follow-up results of LGSIL cases. Results: Cases with LGSIL-H interpretation (311) comprised 0.18% of all cases (170,307). Follow-up was available for 144 patients and 13.2% had benign findings, 51.4% had cervical intraepithelial neoplasia (CIN) 1, and 35.4% had CIN 2 or higher. In comparison, of 425 patients with LGSIL, 22.6% had benign findings, 71% had CIN 1 and 6.4% had CIN 2 or higher. Conclusion: A significantly greater number of patients with LGSIL-H interpretation had a CIN 2 or higher lesion on follow-up compared to patients with LGSIL. This suggests LGSIL-H may be a useful diagnostic category.