Zur Pathologie der Xanthofibrogranulomatose

Summary Two cases are described of an extensive sclerosing lesion involving the retroperitoneum, mesentery, mediastinum and epicardium which is referred as Xanthofibrogranulomatosis. The term was chosen on histological criteria: granulomatous infiltration of chronic inflammatory cells without necrosis, proliferation of spindle-shaped, lipid-laden histiocytes, aggregation of xanthomatous cells and increased production of reticulin and collagenous fibers. Furthermore the name suggests that the lesion tends to be generalized although it does not represent a true neoplasm. In nearly all cases the changes are localized in the retroperitoneal adipose tissue extending to the renal hilus and enveloping the aorta and kidneys; other organs such as adrenals and pancreas are also often surrounded. The frequent cardiac manifestations (14 of 22 cases) with sclerosis of the epicardial fat especially in the right atrioventricular region are conspicous. Moreover involvement of organs may be found, e.g. the lungs or the posterior lobe of the pituitary gland in our cases. Generally the spread of the process shows a striking relation to large blood vessels. However, the distribution lacks uniformity. The characteristic localization and histology allows the distinction of Xanthofibrogranulomatosis from other well known disorders such as Ormond's, retroperitoneal fibrosis, panniculitis (Weber-Christian disease) and histiocytosis X (Hand-Schüller-Christian). The etiology and pathogenesis of Xanthofibrogranulomatosis are uncertain. Perhaps an autoimmune mechanism involving the fat cell membrane may play a part in the genesis of this chronic inflammatory sclerosing process. As long as no rational specific therapy exists, we must interpret the xanthofibrogranulomatous lesion as a slowly but irreversibly progressing disease which is clinically comparable with a malignant tumor.