F-18 FDG PET/CT Imaging of Eccrine Sweat Gland Carcinoma of the Scrotum with Extensive Regional and Distant Metastases.

Eccrine carcinoma is an extremely rare malignant skin cancer arising from eccrine sweat glands with a high metastatic potential. It mainly occurs in the elderly, with equal incidence in both sexes. It usually spreads to regional lymph nodes, with liver, lungs, and bones being the most common sites of distant metastasis. Because of tumor rarity, little is known about the value of F-18 FDG PET/CT in evaluating this disease. Our case report aims to increase current knowledge of F-18 FDG PET/CT in eccrine sweat gland carcinoma as a noninvasive imaging tool for assessing the extension of the disease and detecting distant metastases. We reported a 96-year-old man who presented with as lowly progressive, ill-margined erythematous papules and nodules with a crusted and eroded involving multiple sites of groin, scrotum, penis, left pelvic wall, left hip and left thigh for >3 years, which became extensive in the past 2 months. The histologic investigation confirmed the diagnosis of an eccrine carcinoma. He was performed F-18 FDG PET/CT to further evaluate the lesions. FDG PET/CT imaging revealed FDG uptake at the extensive skin lesion, involvement of lymph nodes, and multiple FDG-avid of liver, skeletal and lung metastases.