[Ectopic breast cancer of the axilla]

Abstract

Introduction: Breast cancer is the most frequent cancer occurring in women. These cancers may rarely develop within ectopic breast tissue. We report a case of ectopic axillary lobular carcinoma presenting as an isolated skin lesion with prolonged evolution.

Case-report: A 62 year-old women had a cutaneous lesion located in her left axilla for the past 4 years. The skin biopsy showed an infiltrating lobular carcinoma. A mammogram and an MRI were as unremarkable as two past mammograms performed since the beginning of the skin lesion. Surgical resection with lymph node dissection, associated with radiotherapy and hormonotherapy with tamoxifen, led to complete remission.

Discussion: Ectopic breast tissue is subject to physiological and pathologic changes such as benign or malignant tumours. Cancer occurring in ectopic breast tissue remains rare but this diagnosis must be suspected when confronted with a skin lesion or mass located near the normal breasts.