Tumor growth of the reticuloendothelial system.

From the author's hitherto studies on the reticuloendothelial system (RES) it was concluded that the RES is not a single cell system of identical origin, morphology and function but is a group of several types of cells of different origin. From this point of view the heterogeneity of tumors of the RES was studied to reveal the following results. Tumors of the "Reticuloendothel" (Aschoff) reveal pictures of endothelioma, while tumors of histiocytes in connective tissue show findings of fibrohistiocytoma. Histiocytes and reticulum cells of lymph nodes are respectively independent cells, and reticulum cells do not partake in the in the development of histiocytosis or histiocytic sarcoma. Follicular lymphoma is a neoplastic growth of reticulum cells having desmosomes in lymph follicles, and tumor cells of the majority of reticulum cell sarcoma are similar to the cells forming the lymph node anlage in the early fetal stage (lymphoreticular cell). Ewing's sarcoma is considered to be a kind of angiopericytoma.