Inflammatory Myoglandular Colorectal Polyps: A Case Series of Nine Patients

Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Endoscopy (Impact Factor: 5.05). 05/2003; 35(4):363-5. DOI: 10.1055/s-2003-38138
Source: PubMed


Inflammatory myoglandular polyp is an uncommon benign colorectal polyp. We treated nine cases of histologically verified inflammatory myoglandular polyp. The polyps were identified as a pedunculated protrusion located in the distal part of the large intestine. On colonoscopy, eight polyps had a smooth, spherical, and hyperemic surface, accompanied by a patchy mucous exudate. Magnification endoscopy revealed a rugged surface composed of smooth nodules. These colonoscopic findings corresponded to hyperplastic glands with occasional cystic dilation and inflamed stroma with proliferation of smooth-muscle fibers. Inflammatory myoglandular polyp appears to be a distinctive clinical entity, with a unique appearance on colonoscopy.

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    • "Moriyama et al. reported magnifying endoscopic findings of 5 IMGPs in 2003 [9]. They described that magnifying observation revealed a slightly rugged surface consisting of aggregated smooth nodules with enlarged round or oval crypt openings. "
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    ABSTRACT: Inflammatory myoglandular polyp (IMGP) is a nonneoplastic colorectal polyp. Only a small number of cases have been reported, and the pathogenesis remains unclear. We analyzed colonoscopy and histologic findings in 4 patients with IMGP. Histologic confirmation of the inflammatory granulation tissue in the lamina propria, proliferation of smooth muscle, and hyperplastic glands with variable cystic changes formed the criteria for the selection of patients. We treated four cases of IMGP and reviewed the literature on this disease. Three cases were located in the sigmoid colon or descending colon. All 4 polyps were identified as red, pedunculated lesions. All 4 cases had no symptoms. In two cases, endoscopic findings of polyps were necessary to be differentiated from juvenile polyps. Pedunculated lesions are the main pattern of IMGP. An analysis of endoscopic and histologic features in IMGP of the colorectum revealed that colonic IMGPs resembled juvenile polyps. On colonoscopy, IMGP should generally be taken into consideration as a differential diagnosis of peduncular polyp.
    Full-text · Article · Apr 2010 · Gastroenterology Research and Practice
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    • "The final diagnosis of IMGP is achieved by histological examination through endoscopic mucosal resection (EMR) or polypectomy, whereas the simple biopsy alone is not enough for a correct diagnosis as in our case. Some authors [8,12] reported a correlation between the characteristic surface of the polyp under magnifying endoscopy and its histological features. As their experience is limited to 10 patients more cases should be studied. "
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    ABSTRACT: Inflammatory myoglandular polyp (IMGP) is a rare non-neoplastic polyp of the large bowel, commonly with a distal localization (rectosigmoid), obscure in its pathogenesis. Up till now, 60 cases of IMGP have been described in the literature, but none located in the cecum. We report a case of a 53-year-old man who was admitted to our hospital for further evaluation of positive fecal occult blood test associated to anemia. A colonoscopy identified a red, sessile, lobulated polyp of the cecum, 4.2 cm in diameter, partially ulcerated. The histological examination of the biopsy revealed the presence of inflammatory granulation tissue with lymphocytic and eosinophil infiltration associated to a fibrous stroma: it was diagnosed as inflammatory fibroid polyp. Considering the polyp's features (absence of a peduncle and size) that could increase the risk of a polypectomy, a surgical resection was performed. Histological examination of the specimen revealed inflammatory granulation tissue in the lamina propria, hyperplastic glands with cystic dilatations, proliferation of smooth muscle and multiple erosions on the polyp surface: this polyp was finally diagnosed as IMGP. There was also another little polyp next to the ileocecal valve, not revealed at the colonoscopy, 0.8 cm in diameter, diagnosed as tubulovillous adenoma with low grade dysplasia. This is the first case of IMGP of the cecum. It is a benign lesion of unknown pathogenesis and must be considered different from other non-neoplastic polyps of the large bowel such as inflammatory cap polyps (ICP), inflammatory cloacogenic polyps, juvenile polyps (JP), inflammatory fibroid polyps (IFP), polyps secondary to mucosal prolapse syndrome (MPS), polypoid prolapsing mucosal folds of diverticular disease. When symptomatic, IMGP should be removed endoscopically, whereas surgical resection is reserved only in selected patients as in our case.
    Full-text · Article · Jan 2010 · BMC Gastroenterology
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    ABSTRACT: The aim of this paper was to report another example of a rare type of colorectal polyps, the inflammatory myoglandular polyp, and to reaffirm this type of polyp as a distinct entity. This solitary pedunculated polyp was detected after a single episode of rectal bleeding. It was situated in the sigmoid colon, measured 2.5 cm in greatest diameter, and was composed almost exclusively of smooth muscles and hyperplastic glands. The patient had neither chronic colitis nor diverticula. Clinical presentation, localization, and histology give this type of polyp a unique appearance and justify its designation as a separate entity.
    No preview · Article · Feb 2003 · Pathology - Research and Practice
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