[Retroperitoneal malignant xanthogranuloma (author's transl)].

A rare retroperitoneal malignant xanthogranuloma is described. The patient developed malignant bone lesions followed by brain localization, and died three years later. At autopsy a very large cystic retroperitoneal tumor with osteolytic lesion of sacrum was found. A review of cases diagnosed as retroperitoneal xanthogranuloma indicates that this lesion seems to be a particular form of the wide group of malignant fibrous histiocytoma with xanthomatous and inflammatory cells. Moreover it could be a primary malignant fibrous histiocytoma of bone. Furthermore, difficulties of differential diagnosis of these tumors are discussed mainly with histiocytosis X.