Defective apoptosis as potential mechanism in the tumorogenesis of myelolipoma

Apoptosis is considered an important mechanism of selective deletion that o ccurs during hematopoiesis. Myelolipoma is a rare benign tumor composed of adipose tissue and hematopoietic cells. The pathogenesis of this benign tum or is still unclear. Analysing the structural levels and apoptosis of norma l human bone marrow (NHBM) and human myelolipoma (HM), the apoptotic events resulted abundantly present in NHBM compared to HM, which showed a small n umber of apoptotic cells. By contrast, Fas expression was strongly present both in NHBM and HM. These findings suggest that an altered function of Fas in myelolipoma is not able to trigger the apoptotic machinery. In conclusi on, we hypothesize that drastic reduction of apoptosis in myelolipoma can b e considered one of the growth regulatory mechanisms.