Case Report
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. May 14, 2009; 15(18): 2287-2289
Published online May 14, 2009. doi: 10.3748/wjg.15.2287
Mucosal Schwann cell “Hamartoma”: A new entity?
Paola Pasquini, Andrea Baiocchini, Laura Falasca, Dante Annibali, Guido Gimbo, Francesco Pace, Franca Del Nonno
Paola Pasquini, Francesco Pace, Department of Pathology, Policlinico Militare Celio, Rome 00184, Italy
Andrea Baiocchini, Franca Del Nonno, Department of Pathology, INMI-IRCCS “L. Spallanzani”, Rome 00149, Italy
Laura Falasca, Lab of Electron Microscopy, INMI-IRCCS “L. Spallanzani”, Rome 00149, Italy
Dante Annibali, Guido Gimbo, Digestive Endoscopy, Policlinico Militare Celio, Rome 00184, Italy
Author contributions: Annibali D and Gimbo G provided the patient; Pasquini P, Baiocchini A, and Del Nonno F performed the histological and immunohistochemical analyses; Pace F participated in acquisition of data; Falasca L and Del Nonno F carried out the design of the study; Falasca L, Del Nonno F and Baiocchini A drafted the manuscript.
Correspondence to: Laura Falasca, PhD, Lab of Electron Microscopy, INMI-IRCCS “L. Spallanzani”, via Portuense 292, Rome 00149, Italy.
Telephone: +39-6-55170403
Fax: +39-6-55170430
Received: February 13, 2009
Revised: April 10, 2009
Accepted: April 17, 2009
Published online: May 14, 2009

Schwannoma is a well-described, benign nerve sheath tumor of the soft tissue, but is rare in the gastrointestinal tract. Gastrointestinal schwannomas are often incidentally discovered as small polypoid intraluminal lesions. In this report, we describe the clinicopathologic and immunohistochemical features of a distinctive neural mucosal polyp composed of a diffuse cellular proliferation of uniform bland spindled cells in the lamina propria that entraps the colonic crypts. Immunohistochemical analysis revealed strong and diffuse positivity for the S-100 protein. To avoid confusion of these solitary colorectal polyps containing pure spindled Schwann cell proliferation in the lamina propria with neural lesions that have significant association with inherited syndromes, it is better to use the designation “mucosal Schwann hamartoma”.

Keywords: Nerve sheath tumors, Gastrointestinal Schwannoma, Hamartoma