Occurrence of alpha-1-fetoprotein in the mammary gland tissue of men with gynecomastia.

Immunohistochemical proof of A1FP production in the mammary gland of a man with gynecomastia is published here for the first time. The immunohistochemical proof of this fetal alpha-1-globulin in the intraductal epithelium of the mammary gland is described on the basis of the case history of a 25-year-old man with a metastasizing malignant teratoblastoma of the gonads. The question, to what extent A1FP-neosynthesis is characteristic for malignant tumors or whether it is a cellular response to specific, in this case hormonal growth stiumli of primary tumors, is also discussed.