LIPOGRANULOMATOUS PSEUDOSARCOID

Abstract

A variety of agents evoke tissue reactions similar or identical to the lesions of Boeck''s sarcoid. These include acid-fast bacilli, fungi, beryllium, silicon and lipids. Since the cause of Boeck''s sarcoid is unknown, it is important to distinguish between tuberculoid granulomas of other etiologies and the granulomas of Boeck''s sarcoid. The term pseudosarcoid preceded by an appropiate modifier to designate the etiology is suggested, e.g., lipogranulomatous pseudosarcoid. These lesions, which result from deposition and phagocytosis of lipids, are well known but have not been as clearly delimited as other pseudosarcoids. They may be classified as exoge- nous (aspirated oils) or endogenous (hyperlipemic states), and localized (focal lesions) or generalized (lung, nodes, liver, spleen and marrow). The systemic lipogranulomas in particular may mimic Boeck''s sarcoid. In routine autopsies and surgical specimens lipogranulomas are most often encountered in the spleen and in the hepatic node of gallbladders. The early lesions are clusters of variable sized lipid droplets. Tuberculoid granulomas composed of coalescent oleophages, epithelioid cells and giant cells appear. In the final stage lipid may entirely disappear; adjacent granulomas containing recognizable lipid droplets provide the only clue to the etiology. The histologic differentiation between lipogranulomatous pseudosarcoid and Boeck''s sarcoid may then be impossible. The presence of asteroids, which appear to be altered lipid or lipoprotein, is not diagnostic.