IMGP is characterized by inflammatory granulation tissue in the lamina propria, proliferation of smooth muscle, and hyperplastic glands with variable cystic change. Only a small number of cases have been reported and the pathogenesis and natural history remain unclear.
An article to be published on August 14, 2008 in the World Journal of Gastroenterology addresses this question. The research team led by Dr. Shoji Hirasaki from Sumitomo Besshi Hospital in Japan described a relatively rare case of loburated-type IMGP in the ascending colon causing hematochezia. They also report the magnifying endoscopy findings of this IMGP.
The patient was a 33-year-old man with hematochezia. A lobulated, peduncular polyp with bleeding, about 40 mm in diameter, was found in the ascending colon at colonoscopy. Endoscopic polypectomy was performed. The histopathology of the specimen showed an IMGP. Lobulated-type IMGP in the ascending colon is rare.
In the view of the authors, the main clinical feature of colorectal IMGPs is hematochezia and endoscopic or surgical treatment is necessary if gastrointestinal bleeding occur. In this case, magnifying observation was performed before polypectomy. Magnifying endoscopy revealed a red rugged surface component, and smooth white nodules with enlarged round or oval crypt openings.