GESTATIONAL SQUAMOUS-CELL CARCINOMA OF THE BREAST - AN UNUSUAL MAMMARY-TUMOR ASSOCIATED WITH AGGRESSIVE CLINICAL COURSE

We report two cases of squamous carcinoma of the breast detected durin g the gestational period. One woman was post-partum and lactating; one was in the first trimester of pregnancy. The lesions were clinically palpable, multifocal, and measured more than 5 cm in their largest dim ension; both had a cystic appearance. They were treated with radical m astectomy. One patient received pre-operatory chemotherapy. Histologic ally, the tumors were poorly differentiated squamous cell carcinomas. No areas of ordinary duct differentiation were seen. Lymph nodes conta ined metastatic squamous carcinoma in both cases. Tumor cells were neg ative for estrogen and progesterone receptors. Also, they expressed a high proliferative index and several markers of tumor progression, inc luding cErb-B2, p53 protein, bcl-2, and epidermal growth factor recept or. One patient died of tumor 5 months following breast surgery and ha d extensive metastases proven at autopsy. The other patient had eviden ce of pulmonary metastases: following cisplatin therapy, she underwent clinical remission. This study shows that squamous carcinoma of the b reast may occur in pregnant or lactating women: it appears clinically distinguishable from the non-gestational type that is usually associat ed with a better prognosis and occurs in peri- or postmenopausal women .