Histopathology on testicular involvement of leukemia with an emphasis on lymphatics.

The human testes in cases of malignant hematopoietic tumors, especially of leukemia, were histologically examined to characterize the mode of leukemic infiltration in comparison with that of malignant lymphoma. Materials were obtained from 56 autopsy cases, composed of 47 of leukemia, 7 of reticulum cell sarcoma and 2 of lymphosarcoma. Leukemic infiltration was confirmed in 43 (19%) of all leukemic cases and the pattern was divided into three types; diffuse, patchy and perivascular. A high grade infiltration was most common in lymphocytic leukemia. The testicular involvement was unexceptionally bilateral with occasional differences in the grade of infiltration, slight to moderate. There was no regional difference in incidence of leukemic infiltration in the testicular interstitium. A thin-walled canal located closely between the proper lamina of seminiferous tubules and the interstitial cell cluster was suggested to be lymphatics, which were extremely irregular in shape and occasionally did not have endothelium. Therefore human testicular lymphatics might not be a constant canal system, but rather akin to narrow tissue space. A network of argyrophilic fibers was pronounced in the lesion of leukemic infiltration. The frequency and grade of an involvement of the testes in malignant lymphoma were lower and lesser than those in leukemia.