Large Colonic Perineurioma Presenting During Evaluation of Chronic Abdominal Pain and Constipation.

Colonic perineuriomas (PNs), also known as fibroblastic polyps, are rare benign mesenchymal lesions. They are typically found in the distal colon, particularly in the rectosigmoid region. These lesions are usually asymptomatic and incidentally detected during routine screening colonoscopy. We present a 44-year-old woman with long-standing lower abdominal pain and constipation. Colonoscopy revealed a large (5 cm), multilobulated polyp, diagnosed as a colonic PN based on histopathologic and immunohistochemical findings.