Intracisternal crystalline arrays of coated parallel tubules in cells of a human osteosarcoma.
Crystalline arrays of coated parallel tubules (CPT) were observed by electron microscopy within dilated cisternae of the rough endoplasmic reticulum of pleomorphic mononuclear cells in a human osteosarcoma. The wall of the peculiar intracisternal tubules consisted of an electron-dense thin membrane-like envelope which appeared to be composed of granular subunits. The electron-lucent tubular core together with the limiting envelope was approximately 15 nm in diameter. A coat of fuzzy material, approximately 10 nm thick, tightly surrounded the membrane-like wall of the tubules. Cross sections of accumulations of CPT showed the tubules to be arranged in a hexagonal crystalline array. The nature and significance of the intracisternal CPT are unknown.
D000328:Adult; D001859:Bone Neoplasms / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D012516:Osteosarcoma / Q000648:ultrastructure*; D013977:Tibia / Q000648:ultrastructure