MORPHOLOGICAL AND HISTOPATHOLOGICAL CHANGES IN THE TESTIS OF HAMSTERS WITH EXPERIMENTALLY-INDUCED MYELOID TUMOR OF GRAFFI. HYPOTHESES FOR METASTASES IN THE TESTIS.
ILIANA ILIEVA*, RENETA TOSHKOVA, ISKRA SAINOVA, ANI GEORGIEVA, IVELIN VLADOV
Institute of Experimental Morphology, Pathology and Anthropology with Museum (IEMPAM) - Bulgarian Academy of Sciences (BAS), Sofia, Bulgaria
*Corresponding author: iilieva@abv.bg
Keywords: myeloid Graffi tumor, myeloid leukemia, testicular metastases, spermatogenesis, peritubular capillaries and intratubular blood vessels
Abstract: Metastatic malignant tumors in the testis are rare phenomenon, probably due to the protection offered by the blood–testis barrier by metastatic developing tumor mass. In this aspect, the current investigation was the first morphological study on testes, using experimental model of Graffi myeloid tumor (GMT) in hamsters. The purpose of the present investigation was to examine the early and late histopathological changes and in vivo-effects of the transplantable GMT on the testicular morphology and spermatogenesis in tumor-bearing hamsters (TBHs). Significant pathological changes in the TBHs from days 10 and 15 post transplantation (p. t.) were not established in comparison to the control group. The results indicated significant changes in the lumen diameter of capillaries in the testes of TBHs from day 25 and day 30 of the experiment, compared with the controls. In parallel with these data, significant extension of the interstitial space between the seminiferous tubules, as well as the presence of many atypical myeloid cells in the lumen of the whole blood vessels’ length in the gonads of the TBHs, were established. Destructive changes in germinal epithelium organization were found in the TBHs from days 25th to 30th p. t. Strong injury and/or suppression of the spermatogenesis were observed in most of the tubules. In the cases of day 30 p. t., proliferation of atypical cells, as well as their infiltration in both tubule lumen and testicular interstitial spaces, near to small blood vessels (neo-angiogenesis), were assessed. The dissemination of these cells additionally injured the seminiferous tubules and probably formed metastases. According to these results, the established changes in the testicular tissue in the blood vessels (in particular capillaries) and in the spermatogenesis process were probably caused by the developing GMT in the organism of the TBHs.