Ovarian tumors arose in 42 of 74 intrasplenic ovarian grafts in gonadectomized mice of the BC strain or of a hybrid group (BC × C3H). Twenty of the intrasplenic grafts were not tumorous, six grafts failed to “take,” and six grafts, also not tumorous, were adherent to the body wall.
Ten subcutaneous ovarian grafts in ovariectomized mice were not tumorous when the hosts were killed up to 733 days later.
Four intratesticular grafts were not associated with neoplasia. One interstitial-cell tumor occurred in one mouse bearing an intratesticular ovarian graft.
Ova and normal follicles were found in almost all the subcutaneous and intratesticular grafts but in none of the intrasplenic grafts. The intrasplenic environment in castrate hosts accelerated age changes in the ovary when the grafts were not adherent to the parietal peritoneum.
The intrasplenic grafts, after their first detection as palpable masses, ranging from 5 to 6 mm. in diameter, were followed for periods of 56 to 430 days. Some tumors grew progressively and slowly, others grew rapidly after brief periods of quiescence, others after long periods of quiescence, others fluctuated in size, and some changed little in mass. Five growth patterns were detected.
The histological characteristics of the tumors permitted classification of five types, three of which were particularly distinct. The tumors of the different histological types showed no consistent growth characteristics. The growth types of the tumors in the hybrid mice were more uniform than in the BC mice. One teratoma arose in relation to an ovarian tubular adenoma.
It was impossible to predict what the future of any small tumor mass in an intrasplenic graft would be until several hundred days after its detection. Some masses even regressed, and the grafts were nontumorous at autopsy.
Subcutaneous transplants of seven of the ovarian tumors showed differences in the growth characteristics of the grafts similar to those observed among the primary tumors.
Tumors of some histological types were almost always associated with evidence of estrogen production. Other types were rarely associated with evidence of the production of any hormone.
Three adrenal cortical tumors, nine pulmonary adenomas, five reticulum-cell sarcomas, two lymphocytic leukemias, one liposarcoma, and one fibrosarcoma were found.
This investigation was supported in part by grants from the Anna Fuller Fund, the Jane Coffin Childs Memorial Fund, and the National Cancer Institute, U.S.P.H.S., Grant C-343. A preliminary report on this study was made at the meeting of the American Association for Cancer Research, April 11–13, 1952. (“Abstr.,” Cancer Research, 12:264, 1952).