The histiocyte in radiology; with case reports of retroperitoneal xanthogranuloma and malignant fibrous xanthoma.

Abstract

The histiocyte is derived from the reticulum cell and is a member of the reticuloendothelial or reticulohistiocytic system. It is capable of enzymatic production, phagocytosis of bacteria, lipids, erythrocytes, cellular and foreign debris. It is also a faculative fibroblast.It participates in systemic diseases such as metabolic histiocytosis, malignant histiocytosis, and histiocytosis-X.It is also the principal cell in many granulomatous diseases including endogenous lipid pneumonia of lung and xanthogranulomatous pyelonephritis of kidney. Malacoplakia also appears to be a type of histiocytic granuloma.Localized neoplastic or reactive tumor of skin, subcutaneous tissue, lung, mediastinum, retroperitoneum, synovium, bursa and tendon sheath have been variously termed histiocytoma, fibrous xanthoma, xanthogranuloma, xanthofibroma, giant cell tumor, pigmented villonodular synovitis, bursitis and tenosynovitis. A very small percentage of these apparently benign lesions are capable of metastasizing.