Postinflammatory pseudotumors of the lung: fibrous histiocytoma and related lesions.

Abstract

Three cases of pulmonary fibrous histiocytoma, sometimes known as xanthogranuloma and fibrous xanthoma, are described. The lesion is part of a spectrum of diseases known as postinflammatory pseudotumors of the lung. It is usually discovered on routine radiographic examination on which it appears as a well circumscribed mass, and it usually has a benign course. The microscopic findings upon which diagnosis is based, the theories of origin, and previously reported cases are discussed.

Inflammatory Pseudotumor of the Liver. MR imaging Findings.

“…According to the WHO Histological Classification of Hepatic Tumors, IPT is a lesion resembling a tumor and is termed either a post-inflammatory tumor or a plasma cell granuloma (Gibson and Sobin, 1978;Schwarts et al 1980). Histologically, IPT shows granuloma-like tissue despite the fact that it is characterized by connective tissue hyperplasia primarily including infiltration of plasma cells.…”

Evolution of a case of lung plasma cell granuloma

“…PCG is an infrequent pathology the pathogenesis of which remains unknown. It has been speculated that it could be a non-specific, inflammatory response to a variety of agents, the most common being pulmonary infection [1, [3][4][5][6], with a history of pneumonia or acute respiratory infections described in up to a third of the cases in some large series [7,8). Although some cases have been reported as associated with different infections, the following point to a viral origin: 1) the existence of an inflammatory infiltrate similar to those produced by viral pneumonia [7]; and 2) the presence of presumed viral particles in the bronchial epithelium in electron microscopic study [9].…”

Inflammatory pseudotumor of the mesentery and small intestine

“…The major body of literature on the topic of inflammatory pseudotumors is devoted to lesions of the respiratory tract [1,7], although they have been reported in other anatomic sites [2,[8][9][10][11][12][13][14][15]. Inflammatory pseudotumors have been designated by different authors as plasma cell granuloma, lymphoid hamartoma, plasma cell pseudotumor, xanthomatous pseudotumor, and fibrous xanthoma [7,9,16]. What is apparent from the individual case studies and small series, our own included, is that the etiology and histogenesis are unknown or incompletely understood [17].…”