@article{AOT9351,
author = {Emma Tam and Kathryn Nunes and K. Rebecca Koob and Stacey M. Gargano and Elizabeth E. Cottrill},
title = {Epidemiological data on 25 cases of mixed-etiology thyroid granulomas: a single-center retrospective cross-sectional study},
journal = {Annals of Thyroid},
volume = {11},
number = {0},
year = {2026},
keywords = {},
abstract = {Background: Thyroid granulomas are uncommon and published data are limited to case reports or narrow single-etiology series, leaving the clinical significance of incidentally identified granulomas poorly defined. The aim of this study was to describe a mixed-etiology cohort of thyroid granulomas to characterize their clinical presentation, histopathologic patterns, and association with malignancy at a single tertiary center.Methods: A single-center retrospective cross-sectional study was performed of adult patients undergoing thyroid surgery between January 1, 2008, and December 31, 2023 with pathology-confirmed granulomatous inflammation involving thyroid tissue. Cases were identified via electronic medical record query. Demographic, clinical, cytologic, and histopathologic data were summarized using descriptive statistics.Results: Twenty-five patients met inclusion criteria. Median age at surgery was 57.2 years (range, 24.3–85.8 years); 72% (18/25) were female. The most common indication for surgery was thyroid nodules (60%, 15/25), followed by suspected or confirmed malignancy (24%, 6/25). Fine needle aspiration (FNA) was performed in 92% (23/25) of patients; 43% (10/23) yielded indeterminate cytology (Bethesda III–IV). Most granulomas were incidental histologic findings (88%, 22/25). Three presented as mass-forming lesions, all yielding Bethesda III cytology that prompted surgical excision. All granulomas were non-necrotizing. Granulomas reflected diverse, predominantly noninfectious histopathologic patterns, most commonly autoimmune or thyroiditis-associated and post-procedural. Coexisting malignancy was identified in 9 patients (36%, 9/25), most commonly papillary thyroid carcinoma. Among these 9 patients, 4 had a history of sarcoidosis; within the sarcoidosis subgroup, 4 of 5 patients had malignancy (80%, 4/5). Given the small subgroup size, this finding should be interpreted cautiously. Special stains for infectious organisms were negative in all tested cases (n=11). No patient developed recurrence of thyroid granulomatous disease over a median follow-up of 12.4 months.Conclusions: In this surgically treated cohort, thyroid granulomas were most often incidental, and reflected diverse, predominantly noninfectious histopathologic patterns. Mass-forming granulomas may mimic malignancy on imaging and cytology despite benign histology, and recognition of this pattern may help avoid misclassification. The association between sarcoidosis and concurrent malignancy is a preliminary finding warranting prospective investigation.},
issn = {2522-6681}, url = {https://aot.amegroups.org/article/view/9351}
}