The utility of [¹⁸F] FDG PET/CT in staging hidradenocarcinoma.

Hidradenocarcinoma is a rare and aggressive malignant cutaneous adnexal tumor that originates from the intradermal ducts of eccrine sweat glands. Herein, we report a case of hidradenocarcinoma that had transformed from a previously excised benign hidradenoma. [F] FDG PET/CT revealed an FDG-avid mass in the left calf, and extensive metastatic disease, including soft tissue, pulmonary, osseous, and extensive nodal metastases. This case underscores the potential for malignant transformation of hidradenoma and highlights the utility of [F] FDG PET/CT in staging hidradenocarcinoma.