[Alpha-1-fetoprotein in tumour tissue (author's transl)].

Using the indirect immunoperoxidase method, alpha 1-fetoprotein (AFP) can be demonstrated in paraffin sections of tumours by light-microscopy. Among 160 tumour preparations it was demonstrated in five of six endodermal sinus tumors, 19 of 40 teratomas, the three hepatoblastomas and 9 of 16 primary liver-cell carcinomas. Among 15 rhabdomyosarcomas, 15 Wilms tumours, 15 neuroblastomas and 15 other malignant tumours only one rhabdomyosarcoma contained AFP. No AFP was demonstrated in 35 various benign tumours and various other human tissue samples. Distribution of AFP-producing cells in tumour tissue is generally focal samples. In malignant teratomas AFP was found only in areas which corresponded to an endodermal sinus tumour or an embryonic carcinoma. The practical significance of the results consists of (1) demonstration and localisation of AFP in tumour tissue; (2) aiding the differential diagnosis and classification of tumours and their metastases; and (3) recognition of pathogenetic connection between embryonic carcinoma and endodermal sinus tumour.