Unilateral indurated plaque in the axilla: a case of metastatic breast carcinoma.

Breast cancer is the most commonly diagnosed cancer among American women and is also the most common internal malignancy to metastasize to the skin. Rarely, cutaneous metastases represent the first indication of breast carcinoma, putting dermatologists in an instrumental position to make the diagnosis of breast carcinoma. We report the case of a 71-year-old woman with a 10-year history of a slowly-enlarging, indurated plaque in the right axilla. Review of symptoms was significant only for occasional numbness and tingling that extended from the right axilla to the right hand. Biopsy revealed cells infiltrating in a single-file between the collagen bundles in the dermis and subcutis and immunohistochemical staining consistent with a diagnosis of invasive lobular carcinoma. Subsequent work up revealed a primary breast lesion and extensive bony metastases.