Transplantation of untreated glandular stomach of fetal and newborn rats and their malignant conversion.

Untreated fetal and newborn glandular stomachs of Wistar rats were transplanted into the subcutis, testis, peritoneal cavity and subcapsular spaces of the kidney or spleen of syngeneic adult rats. The recipients were sacrificed one year after transplantation. Transplantability was very high and the grafted tissues were recovered from more than 80% of the animals at almost all transplantation sites. The transplanted gastric mucosa was well-differentiated morphologically and biochemically. Malignant conversion occurred in 6 of 118 transplants (5%); the tumors were a fibrosarcoma (1), a ganglioneuroblastoma (1), leiomyosarcomas (2) and squamous cell carcinomas (2). No malignant transformation of glandular stomach epithelium was observed.