Pure primary squamous cell carcinoma of the breast: a rare presentation and clinicopathologic comparison with usual ductal carcinoma of the breast

Pure and primary squamous cell carcinomas of the breast are exceedingly uncommon lesions. To the best of our knowledge, based up on review of the literature, only four studies of patients with these tumors, which presented clinically as breast abscess, have been reported previously. We present a woman who sought medical attention for breast pain and was initially diagnosed with a breast abscess. When she did not respond to antibiotic therapy, an incision as well as drainage was performed. Histologic examination of the material revealed a pure squamous cell carcinoma. An extensive work up ruled out other primary sites. She was treated with mastectomy and radiation therapy and has seen disease-free 3 years postdiagnosis. We also review the literature for presenting features, value of imaging studies, role of cytology in diagnosis, and therapy of such tumors in comparison to the usual ductal carcinomas of the breast.