Faculty Bibliography

BACKGROUND: Differentiating parathyroid and thyroid lesions can be challenging because of considerable morphologic overlap and anatomic proximity. Therefore, the authors sought to identify characteristic morphologic patterns and useful adjunct tests to distinguish these 2 entities. METHODS: A search was conducted in the study institution database for clinically indeterminate thyroid nodules from 2000 through 2016 with an emphasis on confirmed parathyroid nodules. Pathology reports, slides, ancillary studies, molecular analysis, and clinical and radiologic data were retrieved. RESULTS: A total of 143 cases of clinically indeterminate thyroid nodules were identified; 34 of these were confirmed parathyroid nodules. Three cytologic patterns were identified: 1) oncocytic cell pattern (9 cases; 26%); 2) follicular lesion of undetermined significance-like/papillary-like pattern (14 cases; 41%); and 3) nonspecific endocrine cell clusters (11 cases; 32%). Bare oval nuclei (100%), nuclear overlap (88%), crowded sheets (88%), and intracytoplasmic vacuoles (62%) were observed. Ten cases (29%) demonstrated positive immunostaining for parathyroid hormone (PTH), 7 cases (21%) demonstrated a positive PTH assay, and 9 cases (26%) had PTH detected by ThyroSeq v.2. The remaining 8 cases were morphologically either indeterminate or suggestive of parathyroid origin. The cytologic diagnosis was confirmed clinically (20 cases) or surgically (14 cases). Based on cytology alone, 8 cases initially were diagnosed as thyroid tissue and amended to parathyroid lesion after ancillary studies were performed, including 5 cases based on ThyroSeq v.2 results alone. CONCLUSIONS: Lesions with follicular lesion of undetermined significance-like or oncocytic features are prone to misdiagnosis. The current study identified distinct cytologic patterns in parathyroid lesions suggestive of parathyroid origin, which, together with PTH immunostains or assay, molecular studies, or sestamibi scans, aid in distinguishing parathyroid from thyroid lesions. Cancer (Cancer Cytopathol) 2017. (c) 2017 American Cancer Society.

Introduction: Because of the indolent nature and potentially conservative treatment of Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features (NIFTP)- an entity recently removed from the malignant papillary thyroid carcinoma (PTC) category, it is crucial to identify features of this entity pre-operatively. Our group has recently published our findings that several statistically significant associations appear to be present between cytomorphologic features and surgical diagnosis that may be used as clues to distinguish NIFTP, PTC and follicular adenoma (FA) on fine-needle aspiration (FNA). Therefore, we set out to determine the reproducibility of these results. Materials and Methods: Pre-surgical FNA slides from NIFTP (n=30), classical PTC (n=30) and FA (n=30) collected from 1/2013-8/2016 were reviewed by 7 cytopathologists blind and independently. Presence of cytomorphologic features was recorded and compared to determine concordance amongst cytopathologists. For each feature, the concordance was compared between NIFTP, PTC and FA by Fisher's Exact Test. Utilizing the majority consensus for presence or absence of each cytomorphologic feature, differences amongst NIFTP, PTC and FA presurgical FNAs were assessed for each feature by Fisher's Exact Test. Results: For all the cytomorphologic features, the concordance rates amongst the pathologists ranged between 78 to 93%. The concordance rates were similar between the NIFTP, PTC and FA groups (Table 1). Comparing each cytomorphologic feature (present/absent determined by majority consensus) amongst the NIFTP, PTC and FA groups displayed statistically significant differences for all features (Table 2). Conclusions: The current study supports our previous findings that there are cytomorphologic differences between the three surgical pathology groups-NIFTP, PTC and FA, and shows that these results are reproducible. The presence or absence of each feature viewed in combination as a profile may assist the cytopathologist in raising the possibility of NIFTP pre-operatively, potentially aiding clinicians in deciding whether a more conservative treatment plan is appropriate. (Table Presented)

The breast is an unusual site for carcinoid metastasis. Due to increasing survival rates for carcinoid tumors, however, awareness of their rare complications is important. Carcinoid metastasis to the breast typically presents as a palpable breast mass or a mass on screening mammogram. Because imaging findings are nonspecific, the diagnosis is established through histological findings of neuroendocrine features corresponding with the known primary carcinoid pathology. Correctly distinguishing metastatic carcinoid from primary breast carcinoma is crucial to avoid more invasive procedures required for the latter. Two cases of metastatic carcinoid to the breast are presented with review of the literature.

Mammary analogue secretory carcinoma (MASC) is a newly described rare salivary gland tumor, which shares morphologic features with acinic cell carcinoma, low-grade cystadenocarcinoma, and secretory carcinoma of the breast. This is the first reported case of MASC of an accessory parotid gland detected by aspiration biopsy with radiologic and histologic correlation in a 34-year-old patient. Sonographically-guided aspiration biopsy showed cytologic features mimicking those of low-grade mucoepidermoid carcinoma, including sheets of bland epithelial cells, dissociated histiocytoid cells with intracytoplasmic mucinous material, and spindle cells lying in a web-like matrix. Histologic sections showed a circumscribed tumor with microcystic spaces lined by bland uniform epithelial cells and containing secretory material. The tumor cells expressed mammaglobin and BRST-2. The cytologic features, differential diagnosis, and pitfalls are discussed. The pathologic stage was pT1N0. The patient showed no evidence of disease at 1 year follow-up. Diagn. Cytopathol. 2014;42:49-53. (c) 2012 Wiley Periodicals, Inc.

G. C. H. Yang, K. Fried and P. H. Levine Detection of medullary thyroid microcarcinoma using ultrasound-guided fine needle aspiration cytology Objective: Compared with incidental papillary thyroid microcarcinoma (microPTC), incidental medullary thyroid microcarcinoma (microMTC) is clinically more significant. The objective of the present study was to summarize our experience in detecting microMTCs. Methods: From 1995 to 2011, there were 10 825 thyroid fine needle aspirates (FNAs) guided using high-resolution ultrasound with on-site preparation and evaluation by a cytopathologist. Of the 140 microcarcinomas detected, 132 were microPTCs and eight were microMTCs, which are the subject of the present study. Results: All eight cases were incidentalomas and none of the five women and three men, age 37-70 years, had a family history of MTC. One patient had two FNAs at an interval of 10 months, two had a single lymph node metastasis and one had a 0.1-cm tumour nodule near the main tumour. Four of five plasmacytoid cell microMCTs had irregular borders; two round cell and one rectangular cell tumours had smooth borders. In contrast, 17 larger MTCs diagnosed in the same period included seven plasmacytoid, four giant cell and six spindle cell types. All five plasmacytoid microMTCs were correctly diagnosed on FNA, but the round cell and rectangular cell tumours were undercalled as follicular lesions. Sampling of colloid from adjacent follicles was noted in microMTCs. Two were diagnosed on histology following recommended surgery and one was diagnosed on recommended repeat FNA. Conclusions: US-guided FNA of thyroid lesions is a powerful tool in the detection of microMTCs, provided that cytopathologists are alerted to the pitfalls described in the present study.

Synopsis We report the utility of office-based, nonimaged guided fine needle aspiration of palpable axillary lymph nodes in breast cancer patients. We examine the sensitivity and specificity of this procedure, and examine factors associated with a positive fine needle aspiration biopsy result. Abstract: Although the utility of ultrasound-guided fine needle aspiration biopsy (FNA) of axillary lymph nodes is well established, there is little data on nonimage guided office-based FNA of palpable axillary lymphadenopathy. We investigated the sensitivity and specificity of nonimage-guided FNA of axillary lymphadenopathy in patients presenting with breast cancer, and report factors associated with a positive FNA result. Retrospective study of 94 patients who underwent office-based FNA of palpable axillary lymph nodes between 2004 and 2008 was conducted. Cytology results were compared with pathology after axillary sentinel node or lymph node dissection. Nonimage-guided axillary FNA was 86% sensitive and 100% specific. On univariate analysis, patients with positive FNA cytology had larger breast tumors (p = 0.007), more pathologic positive lymph nodes (p < 0.0001), and were more likely to present with a palpable breast mass (p = 0.006) or with radiographic lymphadenopathy (p = 0.002). FNA-positive patients had an increased presence of lymphovascular invasion (p = 0.001), higher stage of disease (p < 0.001), higher N stage (p < 0.0001), and higher rate of HER2/neu expression (p = 0.008). On multivariate analysis, radiographic lymphadenopathy (p = 0.03) and number of positive lymph nodes (p = 0.04) were associated with a positive FNA result. Nonimage-guided FNA of palpable axillary lymphadenopathy in breast cancer patients is an inexpensive, sensitive, and specific test. Prompt determination of lymph node positivity benefits select patients, permitting avoidance of axillary ultrasound, sentinel lymph node biopsy, or delay in receiving neoadjuvant therapy. This results in time and cost savings for the health care system, and expedites definitive management