Juvenile milk protein secreting carcinoma.

A case of juvenile secretory carcinoma of the breast is reported. The tumor occurred in a 19 yr-old nulliparous woman and was treated by local resection; it recurred 7 years later. Slight infiltration of the pectoral muscle, metastatic involvement of one lymph node and multifocal areas of carcinoma were found at radical mastectomy. No further recurrence has been detected after 1 year. This case confirms the slow evolution of this neoplasm but stresses that its behavior is not always as indolent as previously believed. We have used histochemical techniques for mucins (PAS, Alcian Blue) and immunoperoxidase methods for milk proteins (MFGM, beta-Casein, alpha-lactalbumin), for myoepithelial cells (actin) and for oncofetal antigens (CEA). Our results suggest that: Immunoperoxidase methods for milk proteins are a more specific and reliable marker than PAS staining in characterizing the secretory activity of juvenile carcinoma. The absence of myoepithelial cells in infiltrative areas detected by immunoperoxidase methods for actin confirms the low degree of organization in this well differentiated carcinoma of limited aggressiveness which secretes milk proteins.