Leukemia of Short Latency in Mice Injected with Human Malignant Tissue by Intrasplenic Route

Summary

Biopsy and/or bone-marrow specimens from human neoplasias were injected, by means of a trocar, into the spleen of 20 young adult BALB mice (I₁). Ten days later, the granulomatous tissue at the site of injection was loaded into a trocar and deposited into the spleen of a 2nd group of 10–20 mice (I_2a); the remaining portions of the spleens were homogenized and inoculated i.p. into a 3rd group of 10–20 mice (I_2b). Again 10 days later, the spleens of mice from group I_2a were homogenized and administered i.p. to a 4th group of 10–20 mice (I₃).

Two cases of stem-cell sarcoma and 1 case of fibrosarcoma gave the following results: in Case 1, 10 of 22 (45%), and in Case 2, all of 10 mice (100%), from the I_2b groups, developed leukemia 40 and 19 days, respectively, after they were injected (and 50 and 29 days, respectively, after the original injection I₁); in Case 3, 15 of 17 mice (88%) from Group I₃ became leukemic 32 days after they were injected (and 52 days after the original injection I₁). In Case 3, these results were confirmed using bone marrow, yielding 4 leukemias in 8 members of the same I₃ group. Cellular transplantation of the leukemias originating from these 3 cases are being carried in serial form.

Both the original and transplanted leukemias were examined under the electron microscope, revealing the presence of A₁ and C viral particles.

These 3 cases are part of a series including 31 human malignancies, mainly lymphomas, with 8 tonsils, 6 muscles, and 3 normal bone marrows as controls. In all but the 3 above-mentioned cases, no leukemias were observed within the same period of time.

No explanation of this phenomenon can be advanced but 3 working hypotheses are submitted.