Jejunal Intussusception Secondary to a Large Inflammatory Fibroid Polyp: A Case Report and Discussion of Differential Diagnosis

Abstract

Inflammatory fibroid polyp (IFP), initially considered a reactive process, is now recognized as a benign mesenchymal neoplasm of the gastrointestinal tract. We report a case of a 68-year-old woman with medically refractory Crohn disease that presented with intussusception requiring surgical intervention. The resection revealed a jejunal mass consisting of a submucosal proliferation of bland spindle cells in a fibrous stroma infiltrated by numerous eosinophils. By immunohistochemistry, the lesion was positive for vimentin and negative for desmin, smooth muscle actin (SMA), S-100, CD117, DOG1, ALK (D5F3), Melan-A, HMB-45, CD34, and STAT6. Ki-67 proliferative index was low (<1%). The mass was classified as IFP by its characteristic morphology and associated eosinophilia. IFP should be considered in the differential diagnosis of adults with intussusception or bowel obstruction. Definitive treatment typically requires surgical resection of the involved bowel segment.

Figure 1

Inflammatory fibroid polyp. (a, b) Low-power magnification showing a predominantly submucosal nodular proliferation with some extension into mucosa comprised of bland spindle-shaped mesenchymal cells, well-vascularized with concentric distribution of inflammatory infiltrate consisting mainly of eosinophils arranged around vessels. (c, d) High-power magnification showing bland spindle cells, small vessels, and eosinophil-rich mixed inflammatory infiltrate. (Hematoxylin and eosin stain: (a) original magnification ×2; (b) original magnification ×10; (c) original magnification ×20; and (d) original magnification ×60).

Figure 2

Immunohistochemical staining showed that the spindle-shaped mesenchymal cells were positive for vimentin (a) and negative for CD34 (b), CD117 (c), DOG1 (d), S-100 (e), SMA (f), STAT6 (g), and ALK (D5F3) (h) (original magnification: ×20).