Light and ultrastructural features of a cerebellar hemangioblastoma in a 56-year-old man are described in detail. The neoplasm was composed of three major cell types: endothelial cells, pericytes, and stromal cells. The endothelial cells lined the fenestrated vascular channels. The pericytes were ensheathed by their own basal lamina which separated them from the basal lamina covering the endothelium. The stromal cells contained, in addition to the conventional organelles, numerous membrane-bound lipid inclusions, annulate lamellae, and nuclear bodies. There were also present transitional cells which shared the fine structure of all the three major cell types. Histogenetically, the tumor was considered to be of vascular origin. The stromal cells represented the stem cells which, under the neoplastic influence, continued to proliferate and differentiate into "vasoformative" elements (pericytes and endothelium) which formed new blood vessels. The transitional forms between the stromal cells and the "vasoformative" elements suggested that the cellular components of a hemangioblastoma shared a common ancestry, most likely of an angioblastic lineage.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.