Benign fibroblastic polyp of the colorectum

Goals: We present the clinicopathologic features, endoscopic appearance, and ultrastructure of a newly described mesenchymal polyp of the colorectum, termed benign fibroblastic polyp. Study: A total of 4 cases from our institution are analyzed using routine histopathology, immunohistochemistry, and electron microscopy, and compared with the original series of 14 cases previously described in the pathology literature. Results: Benign fibroblastic polyps appear endoscopically throughout the colorectum as submucosal lesions with a hyperplastic surface component. These lesions are histologically and ultrastructurally distinct, but overlap with other mesenchymal polyps warrants additional immunohistochemical studies for definitive classification. Conclusions: Benign fibroblastic polyps of the colorectum comprise a recently described distinct entity of mesenchymal polyps that appear to follow an indolent clinical course. Their etiology is uncertain but may be linked to an exuberant tissue response following mucosal injury. Gastroenterologists should be aware of this new entity that will be increasingly diagnosed by pathologists.