[Vascular cellular elements as the source of development of desmoid fibroma]

Electron microscopic radioautography was used to investigate DNA and RNA syntheses in desmoid fibroma pieces ablated at operation. The DNA precursor 3H-thymidine was discovered to be incorporated only into vascular wall cells. RNA synthesis was the most overt in endotheliocytes, pericytes and fibroblasts adjacent to the vessels. At a distance from the vessels the majority of the cells were in a state of destruction. Based on the data obtained the authors arrive at the conclusion that the proliferation of vascular wall cells gives rise to the development of desmoid fibroma providing for the replenishment of tumorous cells. The latter ones, while making the cycle of differentiation and specific function, move away from the vascular lumen and then get destroyed.