Apocrine sweat gland carcinoma: initial evaluation, staging, and response monitoring using 18F-FDG PET/CT.

Primary apocrine sweat gland carcinomas (PASGCs) are rare tumors, commonly located in the axilla. Metastases are common and confer poor prognosis. Given the rarity of these tumors, there is limited knowledge regarding its diagnosis and management. Here we show 18F-FDG PET/CT images of a 61-year-old man with PASGCs of the left axilla. PET/CT confirmed the diagnosis as primary axillary malignancy with nodal, pulmonary, and skeletal metastases. Another interesting finding in this case was the presence of FDG-avid calcified metastatic lymph nodes during the initial evaluation. Follow-up PET/CT showed progression of the disease. FDG PET/CT seems to be a promising tool in the management of PASGCs.