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: Due to the diagnostic dilemma with indeterminate thyroid Bethesda categories III and IV (atypia of undetermined significance, AUS and Suspicious for follicular neoplasm, SFN), many laboratories utilize molecular testing to aid in risk stratification of these nodules. In this study, we evaluated the risk of malignancy (ROM) in AUS and SFN thyroid nodules with subsequent negative molecular (ThyroSeq) test results.
Material(s) and Method(s): This study was designed to evaluate the negative molecular thyroid fine needle aspiration (FNA) cases at a tertiary medical center in the metropolitan area. 109 cases of AUS and SFN thyroid FNAs over 3 years with surgical pathology follow up were included in the study.
Result(s): Of 109 AUS and SFN cases, 4 cases showed insufficient material for ThyroSeq testing (3.7%), 76 cases showed a molecular alteration (69.7%), and 29 cases were negative for an alteration on ThyroSeq (26.6%). Among the cases with negative ThyroSeq results, 26 cases were benign on surgical pathology (89.7%) (7/26 were follicular adenomas), and 3/29 cases were malignant on histopathology (papillary thyroid carcinoma) (ROM=10.3%, Table 1). AUS and SFN cases with molecular alterations showed a significantly higher ROM (ROM= 60.5%) compared to cases testing negative for molecular alterations (p<0.01, z = -4.61).
Conclusion(s): Our study found that indeterminate thyroid nodules that tested negative for a molecular alteration displayed an ROM of 10.3%. This ROM is comparable to the lower limit of ROM of FNA alone (without additional molecular testing data) in the AUS and SFN categories (10-30%), but is significantly lower than the ROM of indeterminate thyroid cases with known molecular mutations. Therefore, clinical follow-up is recommended for thyroid FNA indeterminate nodules, even those testing negative for a molecular alteration, due to the maintained, albeit lower, ROM. [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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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: Diagnosis of microinvasion (MI) in breast core needle biopsy (CNB) can be challenging particularly in a background of carcinoma in situ (CIS) involving sclerosing lesion with periductal fibrosis and lymphocytic infiltrate. Immunohistochemical stains (IHC) for myoepithelial cells aid in confirming MI. Surgical management of MI deviates from CIS as the former includes sentinel lymph node biopsy (SLNB) while the latter typically includes SLNB only when total mastectomy (TM) is planned. We investigated the utility of IHC in diagnosing MI in our CNBs and its impact on final histopathology on surgical excision.
Design(s): We conducted a search for cases of CIS with foci suspicious for MI, in which IHC for calponin and p63 was used to confirm MI (defined as invasive carcinoma <=1 mm) between January 2010 and June 2019. CIS included ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). MI cases diagnosed based on routine histology were also collected for the same time period. Only cases with follow up excision data were included. Cases with synchronous invasive carcinoma were excluded. Clinicopathologic data including age, size, laterality, resection type, SLNB status and biomarker profiles were compared. Graphpad Prism software was used for statistical analysis.
Result(s): We identified 106 cases of CIS (102 DCIS, 4 LCIS), where IHC was used to confirm MI (MI-IHC hereafter). Mean age was 58 years. Of the 106 cases MI-IHC was identified in 24 cases (23%). See table. All 24 MI-IHC cases had SLNB (100%). Of the 82 CIS cases, 39 had SLNB (48%). Relative risk of finding invasive carcinoma/MI on resection in MI-IHC was 1.8 (p=0.03) compared to CIS. There was no correlation between the biomarker profile with the resection outcome in either CIS (p=0.5, Fisher's exact test) or MI-IHC cases (p=3.4, Chi-square test). We identified 7 cases of MI, diagnosed on routine histology without IHC, of which 5 (71%) had invasive carcinoma/MI and 2 (29%) had CIS or no residual carcinoma on resection. Mean size of invasive carcinoma and CIS on resection in this group was 11 mm and 25 mm, respectively. The resection outcome between MI-IHC and MI based on routine histology was not significant (p=0.6). (Table presented)
Conclusion(s): IHC helped diagnose MI in CNB for CIS in 23% of cases. Compared to CIS, the diagnosis of MI-IHC carried a relative risk of 1.8 in finding invasive carcinoma/MI on resection. There was no difference in the significance of the method used for the diagnosis of MI

BACKGROUND:Hurthle cell lesions often pose diagnostic challenges, despite their common occurrence on thyroid fine-needle aspiration cytology (FNAC). The associated molecular alterations are also not well understood. Therefore, our study aimed to delineate the molecular profile of Hürthle cell lesions classified as Bethesda Categories III or IV (atypia of undetermined significance (AUS) or suspicious for follicular neoplasm (SFN)) on FNAC and to correlate this molecular profile with surgical resection findings. METHODS:This study consisted of 188 Hürthle cell lesions with indeterminate cytology and ThyroSeq® v2/v3 molecular testing results. Surgical follow-up was available for 33 cases. RESULTS:The majority of indeterminate Hürthle cell lesions had negative ThyroSeq® results (61%) and were benign on available surgical follow-up. The most prevalent mutations involved the RAS gene (21%), which were associated with benign lesions, non-invasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP), and malignancy. The remaining mutations involved less than 18% of the cases, including PAX8/PPARG (3.7%), TSHR (3.7%), EIF1AX (2.7%), MET (2.1%), PTEN (1.6%), clonal copy number alteration (1.6%), TERT (1.1%), and 0.5% each of GNAS, PIK3CA, and TP53 mutations. On follow-up, 45% were benign, 24% were NIFTP, and 30% were malignant. The malignant cases had different molecular alterations. CONCLUSION/CONCLUSIONS:No single molecular alteration defines cytologically indeterminate Hürthle cell lesions; the majority of cases have low-risk or no molecular alterations and are benign on follow-up. These findings suggest that molecular testing may be useful, but is not definitive, in determining which cases may be managed conservatively; additional studies are needed to fully determine the negative predictive value in ruling out malignancy.

OBJECTIVE:Because of the indolent nature of Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features (NIFTP) and potential requisite for conservative treatment, it is crucial to identify features of this entity pre-operatively. Our group recently published our findings that there are several cytomorphologic features that may be used as clues to distinguish NIFTP, PTC and follicular adenoma (FA) on fine-needle aspiration (FNA). Therefore, we aimed to determine the interobserver reproducibility of these findings. METHODS:Pre-surgical FNA slides from NIFTP (n=30), classic PTC (n=30) and FA (n=30) collected from 1/2013-8/2016 were reviewed by 7 cytopathologists blindly. Presence of selected cytomorphologic features was recorded and compared to determine percent agreement and inter-rater reliability among study cytopathologists using Gwet's AC1 statistics. RESULTS:For all the cytomorphologic features, the overall percent agreement amongst the pathologists ranged between 65.1% and 86.8% (Gwet's AC1 0.30 to 0.80). There was substantial or almost perfect agreement (Gwet's AC1 >0.60) in seven cytomorphologic features in the classic PTC group, in six features in the NIFTP group, and in five features in the FA group. There were no features with poor agreement (Gwet's AC1<0.0). CONCLUSIONS:The current study supports the reproducibility of our previous findings. The high level of agreement amongst pathologists for these groups, and particularly the NIFTP group, supports the notion that when viewed in combination as a cytologic profile, these cytomorphologic features may assist the cytopathologist in raising the possibility of NIFTP pre-operatively. This can potentially aid clinicians in deciding whether more conservative treatment may be appropriate.

Background: Despite their common occurrence on fine-needle aspiration (FNA) biopsies, Hurthle cell lesions often pose diagnostic challenges. The associated molecular alterations are also not well understood. The goal of this study was to delineate the molecular profile of Hurthle cell lesions classified as Bethesda categories III or IV (atypia of undetermined significance (AUS) or suspicious for follicular neoplasm (SFN)) on FNA and to correlate this molecular profile with surgical resection findings. Design: 140 of 575 FNA's diagnosed as AUS or SFN were Hurthle cell lesions, of which 130 had Thyroseq molecular tests; 21/130 had surgical follow-up and the remaining 109/130 cases were lost to follow-up or considered clinically benign. Results: A majority of the Hurthle cell AUS or SFN had negative Thyroseq results (65%). The most prevalent mutations involved the RAS gene (19%). The remaining mutations each involved fewer than 4% of the cases. On surgical follow-up, 29% (6/21) were benign follicular neoplasms (5/6 were Hurthle type) with a variety of associated mutations. 24% (5/21) were non-neoplastic on surgical excision, including Hashimoto's thyroiditis with no mutations and nodular hyperplasia with KRAS or NRAS mutation. Another 24% (5/21) had non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) with different associated mutations. Finally, 24% (5/21) were malignant on surgical excision including Hurthle variant of follicular carcinoma with a variety of associated mutations, invasive follicular-variant of papillary thyroid carcinoma with NRAS mutation and an incidental papillary thyroid microcarcinoma (micro PTC) with KRAS mutations (Table 1). One micro PTC and three NIFTP cases had marked associated Hashimoto's thyroiditis in the surgical specimens. Conclusions: Our study shows the majority of Hurthle cell lesions diagnosed as AUS or SFN on thyroid FNA biopsies have no molecular alterations. Among the molecular alteration identified in Hurthle cell lesions, RAS mutations were the most prevalent; however, they were equally associated with benign lesions, NIFTP and malignant tumors. Therefore, they may not be useful in pre-surgical management decisions. The number of remaining molecular alterations was too small for significant analysis. Interestingly, almost half of the NIFTP and micro PTC cases had a background of Hashimoto's thyroiditis which may have masked the true nature of the lesions during FNA evaluation. (Table Presented)

Could hydroxychloroquine and quinacrine antimalarial therapy for dermatomyositis later attributed to a paraneoplasic manifestation of an ovarian cancer enhance its subsequent response to chemotherapy? Five months after being diagnosed with dermatomyositis, while somewhat improved with hydroxychloroquine, quinacrine and methotrexate, this 63-year-old woman presented with an advanced intra-abdominal epithelial ovarian cancer documented (but not resected) at laparotomy. Neoadjuvant carboplatin/paclitaxel resulted in remarkable improvement of symptoms, tumour markers and imaging findings leading to thorough cytoreductive surgery at completion of five cycles. No tumour was found in the resected omentum, gynaecologic organs, as well as hepatic and nodal sampling thus documenting a complete pathologic response; a subcutaneous port and an intraperitoneal (IP) catheter were placed for two cycles of IP cisplatin consolidation. She remains free of disease 3 years after such treatment and her dermatomyositis is in remission in the absence of any treatment. We discuss a possible role of autophagy in promoting tumour cell survival and chemoresistance that is potentially reversed by antimalarial drugs. Thus, chemotherapy following their use may subsequently lead to dramatic potentiation of anticancer treatment.