title: Crystals in a jugulotympanic paraganglioma.
abstract: The morphologic features of a jugulotympanic paraganglioma are reported. The tumor showed the usual histology of paragangliomas. No sustentacular cells were identified. In the tumorous chief cells there were typical neurosecretory dense-core granules 60-180 nm in diameter. Granules averaging 400 nm in diameter were also observed, sometimes with a regular rhomboid core or crystallized content. Rhomboid crystals were seen in the cytoplasm in membrane-bound spaces and in telolysosomes. The crystals had a substructure consisting of alternating light and dark lines with a periodocity of 5-10 nm. Such crystals had not been reported previously in paragangliomas. The possible origin of the crystals is discussed.
mesh_terms: D003460:Crystallization; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D004428:Ear Neoplasms / Q000648:ultrastructure*; D004432:Ear, Middle; D005260:Female; D006801:Humans; D002479:Inclusion Bodies / Q000648:ultrastructure; D008854:Microscopy, Electron; D008875:Middle Aged; D010235:Paraganglioma / Q000648:ultrastructure*