Inflammatory myoglandular polyps causing hematochezia

Abstract

We report herein three cases of inflammatory myoglandular polyp (IMGP) presenting as hematochezia. The polyps had pedunculated, red, and smooth features, and were 12, 12, and 15 mm in diameter and located in the sigmoid colon, transverse colon, and rectum, respectively. Endoscopic polypectomies were performed. Histologic examination of the recovered specimens revealed inflammatory granulation in the lamina propria mucosa, proliferation of smooth muscle, and hyperplastic glands with cystic dilatation. The three colon polyps were finally diagnosed both clinically and histologically as IMGP. Endoscopists should bear in mind that a polyp featuring endoscopic findings of pedunculation or semipedunculation; a red, smooth, spherical, and hyperemic surface; and patchy mucosa exudation and erosion is likely to be an IMGP.

Keywords: Endoscopic polypectomy; Gastrointestinal hemorrhage; Inflammatory myoglandular polyp.

Fig. 1

Colonoscopic findings of the polyps. (A) A red, peduncular polyp with mucosal hyperemic changes in the sigmoid colon, about 12 mm in diameter (Case 1). (B) A brownish, smooth polyp with mucosal exudation in the transverse colon, about 12 mm in diameter (Case 2). (C) A pinkish polyp with surface erosions in the rectum, about 15 mm in diameter (Case 3).

Fig. 2

Microscopic findings of a polypectomy specimen. (A) Cross-section showing numerous cystically dilated glands (H&E stain, ×20). (B) Hyperplastic glands with variable cystic changes and inflammatory granulation tissue in the lamina propria (H&E stain, ×40). (C) Proliferation of smooth muscle (arrow), eosinophilic infiltration, and inflammatory granulation in the lamina propria (H&E stain, ×100).