[445] Histologic Correlation of Fine Needle Aspirations of 101 Hurthle Cell Lesions

Melissa Yee-Chang, Rajiv Pulinthanathu, Aylin Simsir, Wei Sun. NYU Langone Medical Center, New York, NY

Background: Hurthle cell lesions continue to be a confounding entity for cytopathologists where there are no definitive criteria to decisively distinguish Hurthle cell carcinoma from adenoma or adenomatoid nodules on cytology. Despite the limitations, this study aims to identify the common causes of discrepant results when a diagnosis of FLUS/AUS (Hurthle cell type), Suspicious for Hurthle cell neoplasm, or Hurthle cell Neoplasm is rendered by the cytopathologist.
Design: A total of 197 ultrasound guided-fine needle aspirations were identified from the archives of NYU Langone Medical Center and Bellevue Hospital Center during 2007 through 2012, consisting of consult cases and on-site ultrasound guided aspirations performed by NYU cytopathologists. 101 cases (51%) had surgical follow-up with either partial or total thyroidectomy resections. Diagnoses rendered before 2009 were converted to the current Bethesda terminology. Diagnoses of “Hurthle cell Nodules” were classified as “Suspicious for HN” if a neoplasm was favored by the pathologist or “FLUS” if there was a differential diagnoses of Hurthle cell neoplasm and hyperplastic lesion. Diagnoses of “Hurthle cell Nodule, favor hyperplasia” are excluded from the study.
Results: In comparison with the surgical resection specimens, 51 cases (50.4%) had good correlation between the cytology diagnosis and surgical excision, with 37 cases of Hurthle cell adenomas and 14 cases of Hurthle cell carcinomas identified. Fifty cases (49.6%) showed a discrepancy between the cytology diagnosis and resection. Twenty-four of the discrepant cases were papillary thyroid carcinoma (48%) on resection, including 9 follicular variants and 5 oncocytic variants. The second most frequent cause for discrepancy was Hurthle cell hyperplasia/adenomatoid nodules with oncocytic features, where 21 cases (42%) were identified. Three isolated discrepant cases of medullary carcinoma and 2 cases of poorly differentiated/insular carcinoma were also identified on surgical resection.
Conclusions: Hurthle cell lesions are still a challenging diagnosis for cytopathologists, where only 50% of the cases can be accurately diagnosed on cytology. The most common mistake made on cytology is due to papillary thyroid carcinoma (48%). The second most common cause for discrepant results is Hurthle cell hyperplasia (42%). Close clinical follow-up is necessary when Hurthle cell lesions are detected to avoid misdiagnosing an occult papillary thyroid carcinoma.
Category: Cytopathology

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 91, Tuesday Afternoon


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