Présentation

67 yo lady with a previous history of nephrectomy for a renal cell carcinoma (T2 N0 M0), 2 years ago. Complains of  abdominal pain with melena.

Treated for hypertension. Takes aspirin.

Scan reveals an intestinal mass.  

Surgery: Segmental resection of the small intestin.

Gross description:

The resected segment discloses a firm polypoid mass mesuring 3.5 cm inserted on the intestinal wall protruding thru ulcerative changes of the surrounding mucosa from the submucosa (click on slide mount). The surface is gritty, greenish. Cut surface is whitish, slightly whorled.

Microscopic description:

The mass is mesenchymatous, with a main vascular component, granulation tissue like, with a myxoid background. The latter is scattered by myofibroblastic, repair type, cells and a more less abundant leucocytic infiltrate, with plasma cells and varying amounts of eosinophils.

      The myofibroblastic cells and eosinophils.

The mass is extending by its vascular component thru the muscularis propria and some inflammatory changes are noted on the serosa.

The mucosa distant to the lesion is unremakable, but on higher magnifications a moderate eosiphilic infiltrate is noted with few cryptic intraepithelial degranulation.

Diagnosis:

Inflammatory pseudotumor (Inflammatory fibroid polyp)

Comments: The histological pattern is reminiscent of a florid granulation tissue (pyogenic granuloma) or in some areas with abundant eosinophils, a "nasal inflammatory polyp".

Ackerman's Surgical Pathology: Inflammatory pseudotumor, Inflammatory fibroid polyp

The process occasionally extends to the entire thickness of the wall. Despite some similarities, this entity is probably unrelated to eosinophilic enterities....the principal mesenchymal cell has the features of the myofibroblast, but the immunohistochemical profile is more in keeping with a histiocytic/fibrohistiocytic nature. The lesion is benign and the pathogenesis is unknown....Obstruction and intusseption are two well-known complications of this entity.

The description of the inflammatory pseudo-tumor (no eosinophils) and its clinical setting (child, with a mass, fever, growth failure, weight loss, anemia, thrombocytosis, elevated ESR and polyclonal hypergammaglobulinemia, resolving after surgical removal of the mass) vary with the authors (see GastroIntestinal Pathology, 2nd Ed. Fenoglio-Preiser) and considered different from the inflammatory fibroid polyp, more common in the stomach.