Apocrine Adenocarcinoma with Extramammary Pagetoid Spread into the Groin: a Case Report and a Literature Review

Apocrine adenocarcinoma is a rare form of sweat gland malignancy mostly affecting adults without evident prevalence for sex or race. Clinically, it presents as a single or a multi-nodular mass or plaque in the axillary or anogenital region, with no additional symptoms. This neoplasm is locally invasive, grows slowly and has an ability to metastasize to visceral organs, regional lymph nodes and bones. We report a case of infiltrating apocrine adenocarcinoma on the scrotum and pubic area with extramammary pagetoid spread into the groin. The immunohistological staining patterns suggested that both extramammary Paget’s disease and apocrine adenocarcinoma derived from the apocrine gland, because the tumor cells were positive for cytokeratin (CK) 7 and gross cystic disease fluid protein-15 (GCDFP-15), but negative for CK20 and prostate-specific antigen (PSA). The results of this case study will facilitate the understanding of this malignant tumor.