Inflammatory myoglandular colorectal polyps: a series of seven cases and review of literature

Abstract

Introduction: Inflammatory myoglandular polyp is an unusual but distinct, non-neoplastic type of colorectal polyp, commonly with a distal localization at the recto-sigmoidian level. It was first described in 1992 by Nakamura and his colleagues and it is considered to have few particular histological features.

Material and methods: We report a series of seven cases (two male and five female patients) of myoglandular polyps with different localization from 15 to 40 cm from anus. Only four out of seven cases presented with rectal bleeding, the others polyps we incidentally discovered.

Results: The polyps varied between 4 and 30 mm in the maximum diameter. Grossly, they had firm consistency and smooth reddish surface. Histological examination of the specimens revealed hyperplastic glands with occasional cystic dilatation, proliferation of smooth muscle with no regular distribution, a variable amount of granulation tissue (usually minimal) and no evidence of epithelial dysplasia. All the lesions were removed endoscopically without any complications.

Conclusions: Inflammatory myoglandular polyps are distinct histopathological entities, with insufficiently investigated pathogenesis that can include local trauma, mucosal prolapse or ischemia. Being benign they can be removed endoscopically, surgical treatment being reserved in selected cases.