Masculinizing hormone therapy effect on breast tissue: Changes in estrogen and androgen receptors in transgender female-to-male mastectomies.

PURPOSE: Almost two percent of individuals in the United States identify as gender non-conforming. In the female-to-male (FTM) transgender population, masculinizing hormone therapy with testosterone is commonly prescribed in gender transition. To date, the effects of exogenous androgens on breast tissue and its roles in altering breast cancer risk are poorly understood. This study examines the histopathologic findings in gender affirming mastectomy (GAM) in transgender FTM patients and the effects of exogenous androgens on estrogen receptors (ER) and androgen receptors (AR). METHODS: A retrospective review of pathology specimens obtained between 2017 and 2020 was performed comparing androgen exposed breast tissue with breast tissue without androgen exposure. Breast specimens were obtained from patients who underwent FTM GAM with recorded exogenous androgen exposure. Control breast specimens were obtained from reduction mammoplasty (RM) procedures in cisgender women which were aged matched to the GAM cohort, as well as postmenopausal women with benign/prophylactic mastectomy procedures; all controls were without androgen exposure. The histopathologic findings were assessed. Immunohistochemistry for AR and ER was performed and the score interpreted by digital image analysis. RESULTS: Androgen-exposed breast tissue revealed dense fibrotic stroma, lobular atrophy, thickened lobular basement membranes, and gynecomastoid changes. Longer duration of androgen exposure resulted in a more pronounced effect. The incidence of atypia or cancer was lower in GAM than RM cohort. ER and AR expression was highest in transgender male breast tissue with intermediate duration of exogenous androgen exposure. CONCLUSION: Increased androgen exposure is associated with lobular atrophy and gynecomastoid changes in breast parenchyma. Overall, ER and AR are expressed strongly in lobular epithelium in patients with prolonged androgen exposure. Exogenous testosterone does not appear to increase risk for breast cancer. Additional studies are needed to investigate the mechanism responsible for these changes at a cellular level and its role in cancer development.

Lymphoid cell rich fine-needle aspirations of the salivary gland: What is the risk of malignancy?

Objectives: Lymphoid cell rich fine-needle aspirations (FNAs) of the salivary glands pose a diagnostic dilemma, with a wide range of differential diagnoses that include several benign and malignant entities. There is limited literature regarding the entities that are commonly encountered in this situation. Our goal was to characterize the surgical outcome in these cases and to evaluate the risk of malignancy. Material and Methods: This is a retrospective study at a tertiary care institution. Our database was queried over a 10-year period. FNAs yielding a prominent population of well-visualized lymphoid cells were included in the study. Only cases with surgical follow-up were evaluated. FNAs with epithelial cells, diagnostic features of any entity (such as granulomas or chondromyxoid stroma), history of metastatic malignancy, or scant cellularity were excluded from the study. Lymphoid cells were classified as atypical according to morphologic findings (monomorphism, irregular nuclear contours, and abnormal chromatin patterns). Statistical analysis was performed. Results: Of the 224 lymphoid cell rich FNAs identified, 29 (28%) had surgical follow-up in our data records. Twenty-two were from the parotid and seven from the submandibular gland. Ten cases (35%) were non-neoplastic (benign lymphoepithelial cyst [n = 4], reactive lymph node [n = 5] and chronic sialadenitis [n = 1]). Benign epithelial neoplasms including pleomorphic adenoma (n = 2) and Warthin's tumor (n = 1) were identified in 10% of the cases. One case with non-atypical lymphocytes proved to be a mucoepidermoid carcinoma (n = 1). Lymphomas were detected in 52% (n = 15). Of note, none of these patients had a history of lymphoid malignancy. 8/15 were low-grade and 7/15 were high-grade lymphoma. Most of these cases (11/15) had atypical lymphocytes on FNA. Ancillary studies were available in a few cases and supportive of the diagnosis of lymphoma, including cell block and immunohistochemistry (n = 7, 47%), flow cytometry (n = 3, 27%), and clonality polymerase chain reaction (PCR) (n = 1; 7%). Most of these were performed in cases with atypical lymphocytes. In cases with non-atypical lymphocytes, five cases were malignant on surgical excision (5/17). Morphology on FNA had a specificity of 92% for malignancy and sensitivity of 69%. The positive predictive value on FNA of atypical lymphocytes for malignancy was 92%. Conclusion: Lymphoid cell rich FNAs carry a 52% incidence rate lymphoma in our small study population. Specificity of FNA for malignancy is high (92%) and lymphocyte atypia is a strong predictor of malignancy. Ancillary studies may be of added value in FNAs with non-atypical lymphoid cells. FNA has a valuable role in triaging lymphoid lesions of the salivary glands.

The molecular consequences of androgen activity in the human breast.

Estrogen and progesterone have been extensively studied in the mammary gland, but the molecular effects of androgen remain largely unexplored. Transgender men are recorded as female at birth but identify as male and may undergo gender-affirming androgen therapy to align their physical characteristics and gender identity. Here we perform single-cell-resolution transcriptome, chromatin, and spatial profiling of breast tissues from transgender men following androgen therapy. We find canonical androgen receptor gene targets are upregulated in cells expressing the androgen receptor and that paracrine signaling likely drives sex-relevant androgenic effects in other cell types. We also observe involution of the epithelium and a spatial reconfiguration of immune, fibroblast, and vascular cells, and identify a gene regulatory network associated with androgen-induced fat loss. This work elucidates the molecular consequences of androgen activity in the human breast at single-cell resolution.

Primary mucoepidermoid carcinoma of the breast arising in adenomyoepithelioma.

Mucoepidermoid carcinoma (MEC) and adenomyoepithelioma (AME) are uncommon neoplasms of the breast that are more commonly noted in the salivary glands. AMEs are benign tumours that are known to undergo malignant transformation. This report describes the first case of a MEC arising in AME in a woman in her 50s.

Is ultrasound-guided fine needle aspiration biopsy of axillary lymph nodes a viable alternative to sentinel lymph node biopsy?

BACKGROUND: Axillary lymph node (ALN) ultrasound-guided fine needle aspiration biopsy (US-FNAB), a minimally invasive procedure, may be used for the preoperative evaluation of ALN status of breast cancer patients. Despite the relative ease of use and low cost, paucity of comparative studies and variation in the reported sensitivity of FNAB preclude its clinical utility in evaluation of ALNs. This study aims to determine the accuracy of US-FNAB in detecting metastasis in ALN pre-operatively and to assess US-FNAB as a viable alternative to sentinel lymph node (SLN) excision. METHODS: The 228 consecutive ALN US-FNABs with subsequent histologic follow up performed from 2005 to 2020 in patients with breast carcinoma were retrospectively evaluated. FNAB results were correlated with histologic diagnosis. Sensitivity, specificity, accuracy, and risk of malignancy of FNAB were calculated. RESULTS: 157/228 (69%) FNABs were concordant with histology, 37/228 (16%) discordant. Positive FNAB findings correlated with primary tumor size, grade, number of metastatic lymph nodes and size of metastases. FNAB with negative diagnosis carried a 22% risk of malignancy, atypical 43%, suspicious 80%, and positive a 100% risk of malignancy (100% positive predictive value [PPV]). The sensitivity and specificity were 78% and 95% respectively; accuracy was 77%. SLN biopsy was avoided in all 82 (36%) cases with positive FNAB results. CONCLUSION: Negative FNAB result does not exclude metastatic carcinoma. With 100% PPV, full ALN dissection and/or neoadjuvant chemotherapy can be safely planned after a positive FNAB result, avoiding SLN biopsy, reducing management costs and shortening time interval to definitive therapy.

Commensal bacteria and fungi differentially regulate tumor responses to radiation therapy.

Studies suggest that the efficacy of cancer chemotherapy and immunotherapy is influenced by intestinal bacteria. However, the influence of the microbiome on radiation therapy is not as well understood, and the microbiome comprises more than bacteria. Here, we find that intestinal fungi regulate antitumor immune responses following radiation in mouse models of breast cancer and melanoma and that fungi and bacteria have opposite influences on these responses. Antibiotic-mediated depletion or gnotobiotic exclusion of fungi enhances responsiveness to radiation, whereas antibiotic-mediated depletion of bacteria reduces responsiveness and is associated with overgrowth of commensal fungi. Further, elevated intratumoral expression of Dectin-1, a primary innate sensor of fungi, is negatively associated with survival in patients with breast cancer and is required for the effects of commensal fungi in mouse models of radiation therapy.

Prognostic Impact of Histologic Grade for Papillary Thyroid Carcinoma.

BACKGROUND: While numerous factors affect prognosis in papillary thyroid carcinoma (PTC), the comparative impact of histologic grade has not been well described. Moreover, indications for external beam radiation therapy (EBRT) remain imprecise. We evaluate clinicopathologic characteristics and outcomes for PTC stratified by grade. METHODS: We profiled histologic grade for PTC (well differentiated, moderately differentiated, poorly differentiated) via hospital (National Cancer Database) and population-based (Surveillance, Epidemiology, and End Results) registries. Cox regression was used to adjust for clinicopathologic covariates. Statistical interactions between subtypes and the effect of EBRT on survival were assessed. RESULTS: Collectively, worsening clinicopathologic factors (age, tumor size, extrathyroidal extension, nodal spread, M1 disease) and outcomes (disease-free survival, overall survival) correlated with less differentiated state, across all histologic grades (p < 0.001). Multivariable analysis showed escalating hazard with loss of differentiation relative to well-differentiated PTC (moderately differentiated hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.04-1.41, p = 0.02; poorly differentiated HR 2.62, 95% CI 2.23-3.08, p < 0.001). Correspondingly, greater survival benefit was associated with EBRT for poorly differentiated cases (HR 0.36, 95% CI 0.18-0.72, p = 0.004). This finding was upheld after landmark analysis to address potential immortal time bias (HR 0.37, 95% CI 0.17-0.80, p = 0.01). CONCLUSIONS: Worsening histologic grade in PTC is independently associated with parallel escalation in mortality risk, on a scale approximating or surpassing established thyroid cancer risk factors. On preliminary analysis, EBRT was associated with improved survival in the most aggressive or least differentiated subvariants. Further investigation is warranted to examine the efficacy of EBRT for select poorly differentiated thyroid carcinomas.

Should "suspicious for high-grade urothelial carcinoma" and "positive for high-grade urothelial carcinoma" remain separate categories?

BACKGROUND: The Paris System (TPS) for Reporting Urinary Cytology aims to standardize urine cytology reporting. Per TPS, the diagnosis of "suspicious for high-grade urothelial carcinoma (SHGUC)" is applied in cases that have few urothelial cells with severe atypia but are quantitatively insufficient for a diagnosis of "high-grade urothelial carcinoma (HGUC)." In our study, we compared the diagnostic accuracy and risk of malignancy (ROM) of these 2 categories to assess whether they could be combined in clinical practice to perhaps improve overall interobserver variability. METHODS: All urine specimens with a diagnosis of either SHGUC or HGUC from January 2016 to July 2019 were retrieved from the pathology database of 2 large academic institutions. Only cases with follow-up biopsies within 6 months were included. RESULTS: One hundred eighty-nine cases met the study criteria. Of these, 122 had a cytologic diagnosis of SHGUC, and 67 had a diagnosis of HGUC. Ninety-five (78%) cases from the SHGUC group and 64 (96%) cases from the HGUC group had biopsy-proven HGUC. The majority of cases with discordance had a history of treatment with either intravesical bacillus Calmette-Guérin or mitomycin. The difference in the rate of biopsy-proven HGUC between the SHGUC category and the HGUC category (95/122 vs 64/67, respectively) was statistically significant (P < .001). CONCLUSIONS: The difference in ROM between SHGUC and HGUC was statistically significant in our study cohort. Intravesical chemotherapy was frequently observed in negative biopsy cases in both groups. Our preliminary findings suggest that the 2 TPS categories should remain separate.

Multiplatform molecular test performance in indeterminate thyroid nodules.

BACKGROUND: Approximately 25% of thyroid nodule fine-needle aspirates (FNAs) have cytology that is indeterminate for malignant disease. Accurate risk stratification of these FNAs with ancillary testing would reduce unnecessary thyroid surgery. METHODS: We evaluated the performance of an ancillary multiplatform test (MPTX) that has three diagnostic categories (negative, moderate, and positive). MPTX includes the combination of a mutation panel (ThyGeNEXT®) and a microRNA risk classifier (ThyraMIR®). A blinded, multicenter study was performed using consensus histopathology diagnosis among three pathologists to validate test performance. RESULTS: Unanimous consensus diagnosis was reached in 197 subjects with indeterminate thyroid nodules; 36% had disease. MPTX had 95% sensitivity (95% CI,86%-99%) and 90% specificity (95% CI,84%-95%) for disease in prevalence adjusted nodules with Bethesda III and IV cytology. Negative MPTX results ruledout disease with 97% negative predictive value (NPV; 95% CI,91%-99%) at a 30% disease prevalence, while positive MPTX results ruledin high risk disease with 75% positive predictive value (PPV; 95% CI,60%-86%). Such results are expected in four out of five Bethesda III and IV nodules tested, including RAS positive nodules in which the microRNA classifier was useful in rulingin disease. 90% of mutation panel false positives were due to analytically verified RAS mutations detected in benign adenomas. Moderate MPTX results had a moderate rate of disease (39%, 95% CI,23%-54%), primarily due to RAS mutations, wherein the possibility of disease could not be excluded. CONCLUSIONS: Our results emphasize that decisions for surgery should not solely be based on RAS or RAS-like mutations. MPTX informs management decisions while accounting for these challenges.

NOR-1 distinguishes acinic cell carcinoma from its mimics on fine-needle aspiration biopsy specimens.

Acinic cell carcinoma of the salivary gland (ACC-SG) is characterized by a recurrent chromosomal rearrangement (t(4; 9)(q13; q31)) that upregulates the transcription factor NR4A3. Studies conducted on formalin-fixed paraffin-embedded (FFPE) tissue have found that nuclear expression of a monoclonal antibody NR4A3 (NOR-1) is a sensitive and specific diagnostic marker for ACC-SG. The aims of this study were to evaluate the performance of the NOR-1 antibody and to compare its utility in separating ACC-SG from its mimics on cytology cell block specimens. Cell blocks were obtained from 70 fine-needle aspiration specimens from multiple institutional archives over a 7-year period (2013-2019). These included 10 cases of conventional low-grade ACC-SG, 1 case of dedifferentiated high-grade ACC-SG, and 59 cases of non-ACC-SG. An automated immunohistochemistry system (Bond-III, Leica) was used for the detection of NR4A3, using the commercially available antibody NOR-1 (sc-393902 [H-7], Santa Cruz Biotechnology Inc.). Optimization of the antibody on the cell blocks was successfully completed by increasing the titer from 1:100 (suggested titer for FFPE specimens) to 1:30. Distinct nuclear reactivity was observed in all 11 cases of ACC-SG (10 of 11 with 3+ diffuse nuclear positivity and 1 case with 2+ focal reactivity). Expression of NR4A3 was absent in all non-ACC-SG cases in the cell blocks. Application of the NOR-1 immunohistochemical staining in fine-needle aspirates of salivary gland tumors for which ACC-SG is a diagnostic consideration successfully distinguishes ACC-SG from its cytologic mimics and provides an early opportunity for oncologic intervention.

Incidence and Mortality Risk Spectrum Across Aggressive Variants of Papillary Thyroid Carcinoma.

Importance: While well-differentiated papillary thyroid carcinoma (WDPTC) outcomes have been well characterized, the prognostic implications of more aggressive variants are far less defined. The rarity of these subtypes has led to their consolidation as intermediate risk for what are in fact likely heterogeneous diseases. Objective: To analyze incidence, clinicopathologic characteristics, and outcomes for aggressive variants of papillary thyroid carcinoma (PTC). Design, Setting, and Participants: This cohort study used data from 2000 to 2016 from hospital-based and population-based US cancer registries to analyze aggressive PTC variants, including diffuse sclerosing (DSV), tall-cell (TCV), insular, and poorly differentiated (PDTC) subtypes. These variants were compared against WDPTC and anaplastic cases. Data analysis was conducted from January 2019 to October 2019. Main Outcomes and Measures: Age-adjusted incidence was calculated via annual percentage change (APC) using the weighted least-squares method. Overall survival and disease-specific survival were analyzed via Cox regression. Propensity-score matching was used to adjust survival analyses for clinical and demographic covariates. Results: Collectively, 5447 aggressive PTC variants were identified (including 415 DSV, 3339 TCV, 362 insular, and 1331 PDTC cases), as well as 35 812 WDPTC and 2249 anaplastic cases. Over the study period, a substantial increase in aggressive variant incidence was observed (APC, 9.1 [95% CI, 7.33-10.89]; P < .001), surpassing the relative increases observed in WDPTC (APC, 5.1 [95% CI, 3.98-6.12]; P < .001) and anaplastic cases (APC, 1.9 [95% CI, 0.75-3.05]; P = .003; parallelism P < .007). Survival varied markedly based on histologic subtype, with a wide spectrum of mortality risk noted; 10-year overall survival was 85.4% (95% CI, 84.6%-86.3%) in WDPTC, 79.2% (95% CI, 73.6%-85.3%) in DSV, 71.9% (95% CI, 68.4%-75.6%) in TCV, 45.1% (95% CI, 40.2%-50.6%) in PDTC, 27.9% (95% CI, 20.0%-38.9%) in the insular variant, and 8.9% (95% CI, 7.5%-10.6%) in anaplastic cases (P < .001). These differences largely persisted even after adjusting for inherent differences in baseline characteristics by multivariable Cox regression and propensity-score matching. Conclusions and Relevance: An upsurge in aggressive PTC incidence was observed at a rate beyond that seen in WDPTC or anaplastic thyroid carcinoma. Moreover, long-term survival outcomes for aggressive PTC subgroups exhibit heterogeneous clinical behavior and a wide range of mortality risk, suggesting that treatment should be tailored to specific histologic subtypes. Given increasing prevalence and disparate outcomes, further investigation to identify optimal therapeutic strategies is needed in these diverse, understudied populations.

Impact of the Paris system for reporting urine cytopathology on predictive values of the equivocal diagnostic categories and interobserver agreement.

BACKGROUND: The Paris System (TPS) acknowledges the need for more standardized terminology for reporting urine cytopathology results and minimizing the use of equivocal terms. We apply TPS diagnostic terminologies to assess interobserver agreement, compare TPS with the traditional method (TM) of reporting urine cytopathology, and evaluate the rate and positive predictive value (PPV) of each TPS diagnostic category. A survey is conducted at the end of the study. MATERIALS AND METHODS: One hundred urine samples were reviewed independently by six cytopathologists. The diagnosis was rendered according to TPS categories: negative for high-grade urothelial carcinoma (NHGUC), atypical urothelial cells (AUC), low-grade urothelial neoplasm (LGUN), suspicious for high-grade urothelial carcinoma (SHGUC), and high-grade urothelial carcinoma (HGUC). The agreement was assessed using kappa. Disagreements were classified as high and low impacts. Statistical analysis was performed. RESULTS: Perfect consensus agreement was 31%, with an overall kappa of 0.362. Kappa by diagnostic category was 0.483, 0.178, 0.258, and 0.520 for NHGUC, AUC, SHGUC, and HGUC, respectively. Both TM and TPS showed 100% specificity and PPV. TPS showed 43% sensitivity (38% by TM) and 70% accuracy (66% by TM). Disagreements with high clinical impact were 27%. Of the 100 cases, 52 were concurrent biopsy-proven HGUC. The detection rate of biopsy-proven HGUC was 43% by TPS (57% by TM). The rate of NHGUC was 54% by TPS versus 26% by TM. AUC rate was 23% by TPS (44% by TM). The PPV of the AUC category by TPS was 61% versus 43% by TM. The survey showed 33% overall satisfaction. CONCLUSIONS: TPS shows adequate precision for NHGUC and HGUC, with low interobserver agreement for other categories. TPS significantly increased the clinical significance of AUC category. Refinement and widespread application of TPS diagnostic criteria may further improve interobserver agreement and the detection rate of HGUC.

Update on Molecular Testing for Cytologically Indeterminate Thyroid Nodules.

Fine needle aspiration biopsy (FNAB) and ultrasonography are the most common modalities for the diagnosis and follow up of thyroid nodules. FNAB is able to distinguish benign from malignant nodules with high sensitivity and specificity; however, 20% to 30% of nodules are diagnosed as indeterminate with a risk of malignancy varying from 10% to 75% based on the 2017 revision of the Bethesda System for Reporting Thyroid Cytopathology. Molecular tests are being increasingly used to triage this group of nodules. Several molecular tests are commercially available and newer upgrades are being developed to either "rule in" or "rule out" malignancy with greater accuracy. The Afirma gene expression classifier and its recent upgrade (the Afirma gene sequencing classifier), Thryoseq v2, a next generation sequencing test and its recent upgrade (the v3), RosettaGX Reveal based on microRNA alterations, and ThyGenX/ThyraMIR, a combination test, are currently on the market. Familiarity with these tests, their performance, and postvalidation publications will enable appropriate test selection and improve triage of patients for appropriate therapy. The underlying rate of malignancy at different institutions and the interobserver variability in cytologic and histologic diagnosis of thyroid lesions are important factors that impact the performance of the various molecular tests.

Procurement and Storage of Pleural and Peritoneal Fluids for Biobanking.

There is limited information regarding the biobanking of pleural and peritoneal fluids that might supplement storage of pulmonary and thoracic tissue biospecimens. Such fluids are sometimes collected for clinical analyses and may have uses that obviate or supplement tissue samples. There has been a growing interest in using liquid biopsies as they are less invasive and may be amenable to analyses that guide targeted therapies. Integrating cytology and biobanking approaches, we describe techniques that may be used for collecting and banking pleural and peritoneal fluids.

Smooth Muscle Cells in Pelvic Washings at Time of Benign Hysterectomy.

STUDY OBJECTIVE: To evaluate if smooth muscle cells can be detected in pelvic washings at the time of intact hysterectomy. DESIGN: A multicentered pilot cohort study (Canadian Task Force classification II-2). SETTING: Two academically affiliated tertiary referral centers. PATIENTS: Patients undergoing total hysterectomy for benign indications without morcellation by minimally invasive gynecologic surgeons were enrolled from January 2018 to July 2018. INTERVENTIONS: Pelvic washings were collected at 2 times during surgery: after abdominal entry and after vaginal cuff closure. Cell blocks were generated, and slides were stained using hematoxylin and eosin, smooth muscle actin, and desmin and interpreted by 1 expert pathologist at each institution. MEASUREMENTS AND MAIN RESULTS: Thirty-eight subjects were recruited; 3 subjects were excluded because of unplanned morcellation. Smooth muscle uterine cells were detected in 1 prewash specimen and 2 postwash specimens. The group with positive washings was noted to have longer procedure times (136 vs 114 minutes), lower blood loss (25 vs 86 mL), and higher uterine weight (242 vs 234 g) compared with negative washings group. CONCLUSION: Tissue dissemination of uterine cells may be possible at the time of hysterectomy. Larger prospective studies are needed to better describe the incidence of and risk factors for tissue dissemination.

A retrospective analysis of the performance of the RosettaGX® Reveal™ thyroid miRNA and the Afirma Gene Expression Classifiers in a cohort of cytologically indeterminate thyroid nodules.

BACKGROUND: Molecular tests are increasingly used to triage cytologically indeterminate thyroid nodules for surgery and/or follow-up. We retrospectively compared the performance of the Afirma Gene Expression Classifier (AGEC) with that of the more recently developed RosettaGX® Reveal™ miRNA Classifier (Reveal) in a cohort of Bethesda III-V thyroid FNAs with surgical follow-up. DESIGN: Eighty-one samples (54 Bethesda III, 26 Bethesda IV, 1 Bethesda V) with available AGEC (74 AGEC-SUSP and 7 AGEC-BENIGN) and surgical pathology results were studied from three academic centers. Reveal was performed in a blinded fashion. RESULTS: The final diagnoses were benign/NIFTP (n = 63) and malignant (n = 18). The overall "correct" rate was 64.2% for Reveal and 28.4% for AGEC (P = 1.4e-6). The specificity of Reveal was 60.3%, compared with 9.5% for AGEC (P = 2.1e-9). Among the 18 malignant cases, 77.8% and 94.4% were correctly classified as suspicious by Reveal and AGEC, respectively (P = 0.2). In the FLUS and the FN group, the specificity of AGEC was lower than the specificity of Reveal. Whether the 7 NIFTP in our study were considered benign or malignant, specificity and PPV of Reveal were higher than those of AGEC. Reveal also outperformed AGEC in correctly classifying the 26 benign Hürthle lesions studied (P = 7.6e-5). CONCLUSION: Reveal outperformed AGEC in this cohort, whether NIFTP is considered benign or malignant, and in Hürthle lesions. Reveal has the potential to reduce the number of unnecessary resections in patients with indeterminate thyroid cytology. Based on our findings and the practical advantages offered by Reveal methodology, large prospective studies are warranted. Diagn. Cytopathol.