Angiography of angiomatous lymphoid hamartoma (Castleman tumor) and a suggested pathogenesis.

The histological nature and angiographic characteristics of two cases of Castleman tumor support the concept that these tumors are hamartomatous. On angiography, both tumors exhibited a dense and homogeneous blush in the later phase. In one, in the mediastinum, hypertrophied branches of the bronchial artery gave rise to multiple irregular vascular spaces within the tumor; in the other, in the retroperitoneum, hypertrophied branches of the lumbar artery gave rise to irregular vascular channels spaced throughout the tumor. Histologically, both lesions contained numerous lymphoid follicles which, in the central portion, contained capillary vessels with thick hyalinized walls and prominent endothelial cells. A pathogenesis of hamartoma formation is suggested based on a disturbance of the normal orderly replacement of somatic cells and tissues.