title: Ultrastructural study of a sarcomatoid variant of renal cell carcinoma.
abstract: The light and electron microscopic features of a sarcomatoid variant of renal cell carcinoma are presented. On light microscopic examination, the initial biopsy specimen showed only a sarcomatoid pattern, but rare transitions to a papillary adenocarcinoma were seen in a few metastatic foci in subsequent autopsy material. However, ultrastructural examination of the biopsy tissue showed complex desmosomal junctions, confirming the epithelial nature of the neoplasm. Complex lateral plications suggested a renal tubular cell origin. We fell that electron microscopic examination of biopsy material in such cases can be of diagnostic value.
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000648:ultrastructure*; D000231:Adenocarcinoma, Papillary / Q000473:pathology / Q000648:ultrastructure; D006801:Humans; D002479:Inclusion Bodies / Q000648:ultrastructure; D007680:Kidney Neoplasms / Q000473:pathology / Q000648:ultrastructure*; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D010784:Photomicrography; D012509:Sarcoma / Q000473:pathology / Q000648:ultrastructure*