BENIGN TRANSFORMATION OF TESTICULAR TUMOR

Abstract

Seven patients with disseminated non-seminomatous testicular cancer were treated by surgical removal of metastatic foci, following chemotherapy using a combination of actinomycin-D, methotraxate, cyclophosphamide and vincristine, or a combination of cis-diamminedichloroplatinm, vinblastine and bleomycin.
In 2 out of the 7 cases, resected metastatic tissues proved to be mature teratoma. The primary tumors of these 2 cases were embryonal carcinomas and contained no choliomatous elements.
The levels of tumor markers (serum α-fetoprotein and urinary human cholionic gonadotropine) in these 2 case before surgery fell within a normal range by chemotherapy.
The metastatic foci which turned into differentiated tissues (teratoma) were cystic and spongy macroscopically. Microscopically these differetiated tissues were composed of glandular epitherium and smooth muscle cells.
In our experiments, cis-diamminedichloroplatinum, vinblastine, and bleomycin in combination was administered to nude mice (BALE/C strain) bearing with human embryonal carcinoma. In some of these mice, tumor cell differention was observed.
With regard to the mechanism of tumor maturation, the following can be considered from our experiences. (1) Embryonal carcinomas have totipotential ability. (2) Totipotential malignant cells can turn into mature teratoma by chemotherapy. (3) Differentiation of totipotential malignant tumors is influenced by cell kinetics and biological response.