Fibrous inflammatory polyps of the ileum and cecum: review of five cases with emphasis on differentiation from mesenchymal neoplasm.

Five case histories of patients with fibrous inflammatory polyps of the ileocecum are reported. Clinical impression in all five cases was that these tumefactions represented gastrointestinal malignancies. Gross pathologic examination revealed polypoid intramural growths ranging from 2.5 to 7.0 cm in greatest dimension. Transmural desmoplasia through the bowel wall into subserosal fat was initially thought to be indicative of neoplastic invasion. Microscopic evaluation revealed a fibroblastic and vascular proliferative process. Pseudosarcomatous changes were identified in cellular fibroblastic areas with plemorphism and mitotic activity. The manner of dissection among bundles of muscularis mucosae and muscularis propria suggests an inflammatory process as opposed to the pushing aside of whole large muscle bundles as seen in mesenchymal neoplasms arising in bowel wall. All five patients experienced survival of 6 to 17 years following surgery. These lesions are thought by us to represent localized exuberant polypoid granulation tissue proliferations which simulate mesenchymal neoplasm.