Ovarian Thecal Metaplasia of the Adrenal Gland: A Contemporary Case Series With Immunohistochemistry

"Ovarian thecal metaplasia" (OTM), a spindle cell proliferation in the adrenal gland, is a rare lesion that is predominantly found in postmenopausal women. Here we present 5 patients with OTM in adrenalectomy specimens resected for adrenal and nonadrenal tumors in women aged 42 to 80 years old. Extended immunohistochemical analysis was performed using contemporary markers, which revealed expression of desmin (DES), HHF35 (ACTA1), inhibin alpha (INHA), SF1, and WT1. Histologic recognition of this lesion and knowledge of its expression can aid in identification and prevent misclassification.