The peak incidence is during middle age, and there is a slight male predominance. There is no racial predilection.
The clinical presentation of AA is variable. It typically presents as a solitary, asymptomatic, erythematous or violaceous nodule that measures 2-3 cm. It can grow slowly, or it may be rapidly progressive and aggressive.
Typical locations are those with high apocrine gland density, such as the axillae. However, lesions can occur anywhere on the skin because of the presence of ectopic apocrine glands. A case arising in an accessory nipple in the axilla and one arising in a nevus sebaceus have been reported. Tumors arising in the anogenital region may be considered as carcinomas of the anogenital region by some pathologists.
C44.99 – Other specified malignant neoplasm of skin, unspecified
57141000 – Apocrine adenocarcinoma
Differential Diagnosis & Pitfalls