Xanthoma and cholesterol granuloma of the choroid plexus. Report of the pathological aspects in 29 cases.

Only 9 cases of xanthoma or cholesterol granuloma were recorded in the literature prior to the report of 20 cases of xanthoma of the choroid plexus by Wolf, Cowen, and Graham (26), of which 1 (their case 8) was published separately (25). Cholesterol granuloma in the ventricular system of man was first described by Blumer (2) under the term "cholestomatous endothelioma." Other terms employed were "cholesteatoma" (4, 5, 17), "xanthoma" (16, 18, 19), and "angioreticuloma" (7). Dandy (6) regarded the lesion in his Case 3 as "perhaps [a] tumor of embryonal cells from which epithelium of the choroid plexus or ependyma is derived," but to us the lesion appears to be a clear-cut cholesterol granuloma. Stern and Levy (21) reported the presence of a cholesterol-containing tumor of the Illrd ventricle, but we doubt that it is of the same category as those reported in this paper. Henschen (13) distinguished between xanthomas and cholesterol granulomas of the choroid plexus, and Stewart (22) referred to xanthomas, but neither of these authors reported individual cases. Wolf, Cowen, and Graham (26), on the other hand, did not deal with xanthoma and cholesterol granulomas separately in their series, but did describe cholesterol granuloma in some of their xanthomas. Dunn and Kernahan (7a) found foam cells and evidence of cholesterol in degenerating parts of the connective-tissue core of the plexus, whereas cholesterol clefts were rare. In 24 cases of cholesterinosis of the choroid plexus, Trelles, Aranibar and Zevalloz (22a) described 3 histological forms: (I) Cystic, in which there was diffuse hyaline material which contained birefringent and clear zones, with reactive fibroblastic reaction around stored calcium and foci of foam (xanthoma) cells, (2) N odulo-cystic, similar to (I) but with a predominance of foam cells with cholesterol clefts, and (3) Nodular, characterized predominantly by foam cells, the central area of which contained cholesterol clefts with connective tissue and other reaction in such quantity as to constitute a cholesterol granuloma. The present article deals with 9 cases of xanthoma and 20 of cholesterol granuloma of the choroid plexus.