The so called 'sweat gland carcinoma' is a rare skin malignancy. The differentiation between apocrine and eccrine neoplasms remains difficult. Skin tumors of the axilla are often suspected to be metastasis of other neoplasms in particular breast cancer. A 71-year-old man presented with a morphea-like plaque of the right axilla which in punch biopsy was first suspected as metastasis of primary lobular breast carcinoma. After further clinical and laboratory work up including immunohistochemistry the original diagnosis of a breast cancer had to be changed to solid apocrine carcinoma of the skin. Wide excision with en-bloc axillary lymph node dissection was performed. Final tumor stage was pT2 N0 M0 (V0 L0). No adjuvant treatment was necessary, and there is no evidence of disease after 3 years. Solid apocrine carcinoma of the skin is a rare variant with apocrine differentiation. A survey of the stereotypical presentation of this lesion and a comparison with lobular breast carcinoma and other types of apocrine carcinoma of the skin is given.

An unusual apocrine carcinoma on the forehead. Am J Dermatopathol. 2007 Aug;29(4):404-7.

We herein report an unusual case of apocrine carcinoma on the forehead. The lesion was formed by the anastomosis of numerous tubular structures with widespread decapitation secretion, thus demonstrating apocrine differentiation. However, we observed some unusual histopathologic features that differed from those found in typical examples of apocrine ductal carcinoma, namely: 1) a relatively well-circumscribed lesion in the dermis, and 2) nodular or solid aggregations composed of basaloid cells. We believe the present case is an apocrine ductal carcinoma, although it has a nodular appearance and basaloid cells. Otherwise, it could be a hitherto undescribed variant of apocrine carcinoma. This apocrine carcinoma on the forehead may have originated from either pluripotential cells or from apocrine glands at an unusual site.