Primary squamous cell carcinoma of the breast after cured bilateral breast cancer

Primary squamous cell carcinoma (SCC) of the breast is a rare and aggressive neoplasm that constitutes approximately 0.1% of all breast carcinomas. Before the tumor can be classified as a true SCC of the breast, certain criteria need to be fulfilled. These are: i) more than 90% of the malignant cells must be of squamous cells origin; ii) tumor is independent from the overlying skin and nipple; iii) other sites of primary SCC have been excluded.

We describe a case of pure SCC of the breast that arose 15 years after local radiation for a primary adenocarcinoma of the breast in a 54-year-old woman with history of bilateral breast cancer. The tumor was triple-negative with a high Ki-67 index. The patient underwent adjuvant chemotherapy with docetaxel and oral fluorouracil.

There are no specific guidelines for the treatment of primary SCC of the breast. Larger series are necessary to determine if different strategies of treatment and follow-up are necessary and if prognosis is really comparable to other histotypes of cancers of the breast.