Inflammatory fibroid polyp of the small intestine: ultrastructural and immunohistochemical observations.
The ultrastructural and immunohistochemical features of a primary tumor of the ileum showing the classic histologic features of an inflammatory fibroid polyp (IFP) of the gastrointestinal tract are presented. Ultrastructurally the proliferating cells showed a combination of fibroblastic and histiocytic features, with abundant rough endoplasmic reticulum and active production of collagen in many of the cells and long, dendritic cytoplasmic projections with large cytoplasmic vacuoles containing remnants of phagocytosed cellular debris in others. Immunohistochemical studies showed strong cytoplasmic positivity in the proliferating cells with vimentin antibodies and scattered positivity with muramidase. Additional findings include the ultrastructural demonstration of oligocilia and occasional primitive intercellular junctions. The findings in this case suggest that IFP may represent a proliferation of primitive submucosal stromal cells exhibiting incomplete fibrohistiocytic differentiation.
Suster
S
S
Department of Pathology, Mount Sinai Medical Center, Miami Beach, Florida 33140.
Robinson
M J
MJ
D000368:Aged; D002467:Cell Nucleus / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D006056:Golgi Apparatus / Q000648:ultrastructure; D006801:Humans; D007078:Ileal Neoplasms / Q000648:ultrastructure*; D007124:Immunoenzyme Techniques; D007417:Intestinal Polyps / Q000648:ultrastructure*; D008297:Male; D008854:Microscopy, Electron; D009113:Muramidase / Q000032:analysis; D014746:Vimentin / Q000032:analysis
D014746:Vimentin; D009113:Muramidase