Schwannoma of ascending colon treated by laparoscopic right hemicolectomy
© Kim et al.; licensee BioMed Central Ltd. 2012
Received: 27 January 2012
Accepted: 12 March 2012
Published: 15 May 2012
Schwannomas of the colon are rare and are difficult to diagnose preoperatively, since they often defy endoscopic and radiographic detection. Immunohistochemical stains are useful postoperatively to confirm this tumor, but more reliable diagnostic techniques (such as colonoscopic biopsy with immunohistochemistry) have emerged to enhance preoperative diagnostic accuracy. Here we report an instance of schwannoma arising in the ascending colon, where immunohistochemical staining of a preoperative biopsy facilitated diagnosis. After laparoscopic resection, histologic examination was confirmatory.
Schwannomas of the gastrointestinal tract are relatively uncommon and rarely involve the large intestine [1–3]. Although considered benign, they may recur locally (if incompletely excised), and malignant transformation is occasionally observed [4, 5]. Radical surgery is, therefore, the accepted standard of treatment.
While accurate diagnosis prior to surgical intervention can aid in therapeutic planning, limitations of conventional imaging and lack of sufficient biopsy material usually make this difficult. Recent improvements in colonoscopic techniques have led to use of endoscopic biopsy and immunohistochemistry in combination as a more reliable method for accurate preoperative assessment. We report here an instance of schwannoma of the ascending colon, confirmed by immunohistochemistry, for which laparoscopic right hemicolectomy was performed.
Schwannomas are uncommon neoplasms arising from Schwann cells of the neural sheath [2, 6]. They may occur anywhere in the body, but gastrointestinal sites are rare, especially the colon [1–3, 7–12]. Depending on tumor size and location, schwannomas of the colon may occasionally produce symptoms, such as constipation, bleeding, abdominal pain or discomfort, and anal pain [2, 10]. Intussuception is unusual . Most patients, however, have no symptoms, because these are inherently slow-growing neoplasms [9, 13]. In our patient, tumor discovery was incidental.
Preoperative diagnosis of schwannoma is difficult due to its tissue density and the tendency for ulceration . Biopsies are often nondiagnostic, and information gained by other means is limited. Colonoscopy, abdominal ultrasound (US), abdominal CT and abdominal magnetic resonance imaging (MRI) may aid in evaluating the contours of colorectal schwannomas and their relationship with surrounding organs, as well as tumor multiplicity or metastasis. Levy, et al.  described gastrointestinal schwannomas as homogeneously attenuated and well-defined mural masses on CT, noting that they were indistinguishable from gastrointestinal stromal tumors. Low-attenuation hemorrhage, necrosis and internal degeneration constituted shared CT features. Attributes signifying benign vs malignant behavior were not addressed [15, 16]. More recently, endoscopic ultrasonography (EUS) surpassed other imaging modalities in diagnostic accuracy but still will not differentiate a schwannoma from other gastrointestinal stromal tumors. EUS-guided fine needle aspiration or biopsy of submucosal tumors has been attempted [17–20].
Schwannoma of the colon usually is not diagnosable solely by routine histology. A newer, more reliable approach incorporates immunohistochemistry [2, 7]. Characteristically, these tumors are composed of spindle cells (much like neurofibromas, gastrointestinal stromal tumors and leiomyomas) [7, 21] that are 100% immunoreactive for S-100 protein. Cells of neurofibroma show less S-100 positivity (30% to 40%), while gastrointestinal stromal tumors are generally positive for CD117(c-kit) and CD34 (70%) and negative for S-100 protein. Leiomyomas similarly are devoid of S-100 protein, expressing smooth muscle actin and desmin instead [22, 23].
Because the prognosis for schwannoma differs from other gastrointestinal stromal tumors, a correct diagnosis is critical. Schwannomas overall are considered benign, but they may recur locally if excision is incomplete and in rare instances are capable of malignant transformation [4, 5]. Tozbikian et al.  found that gastric schwannomas on occasion could be aggressive, progressing rapidly and responding poorly to chemotherapy.
Standard treatment for schwannomas is complete surgical resection [4, 24]. The role of radiotherapy or chemotherapy to date remains unclear [4, 25]. Lymph node resection is not recommended, because the risk of malignant change is low [24, 26]. A minimally invasive procedure (in our case, laparoscopic surgery) is acceptable for schwannoma of the colon and rectum [8, 13, 27]. Our patient resumed oral feeding on the second postoperative day and after an uneventful stay, was discharged on the sixth postoperative day. In clinical follow-up, he has been well and problem-free.
In conclusion, schwannomas of the ascending colon are rare tumors dependent upon immunohistochemistry for definitive classification. Accurate preoperative diagnosis is essential for appropriate surgical management. While radical resection affords optimal outcomes, a laparoscopic approach may be used.
Written informed consent was obtained from the patient for publication of this report and any accompanying images.
- Abraham SC: Distinguishing gastrointestinal stromal tumors from their mimics: an update. Adv Anat Pathol. 2007, 14: 178-188. 10.1097/PAP.0b013e318050aa66.View ArticlePubMedGoogle Scholar
- Inagawa S, Hori M, Shimazaki J, Matsumoto S, Ishii H, Itabashi M, Adachi S, Kawamoto T, Fukao K: Solitary schwannoma of the colon: report of two cases. Surg Today. 2001, 31: 833-838. 10.1007/s005950170060.View ArticlePubMedGoogle Scholar
- Chetty R, Vajpeyi R, Penwick JL: Psammomatous melanotic schwannoma presenting as colonic polyps. Virchows Archiv. 2007, 451: 717-720. 10.1007/s00428-007-0453-0.View ArticlePubMedGoogle Scholar
- Fotiadis CI, Kouerinis IA, Papandreou I, Zografos GC, Agapitos G: Sigmoid schwannoma: a rare case. World J Gastroenterol. 2005, 11: 5079-5081.PubMed CentralView ArticlePubMedGoogle Scholar
- Tozbikian G, Shen R, Suster S: Signet ring cell gastric schwannoma: report of a new distinctive morphological variant. Ann Diagn Pathol. 2008, 12: 146-152. 10.1016/j.anndiagpath.2006.12.004.View ArticlePubMedGoogle Scholar
- Matsuki A, Kosugi S, Kanda T, Komukai S, Ohashi M, Umezu H, Mashima Y, Suzuki T, Hatakeyama K: Schwannoma of the esophagus: a case exhibiting high 18 F-fluorodeoxyglucose uptake in positron emission tomography imaging. Dis Esophagus. 2009, 22: E6-E10. 10.1111/j.1442-2050.2007.00712.x.View ArticlePubMedGoogle Scholar
- Hou YY, Tan YS, Xu JF, Wang XN, Lu SH, Ji Y, Wang J, Zhu XZ: Schwannoma of the gastrointestinal tract: a clinicopathological, immunohistochemical and ultrastructural study of 33 cases. Histopathology. 2006, 48: 536-545. 10.1111/j.1365-2559.2006.02370.x.View ArticlePubMedGoogle Scholar
- Park KJ, Kim KH, Roh YH, Kim SH, Lee JH, Rha SH, Choi HJ: Isolated primary schwannoma arising on the colon: report of two cases and review of the literature. J Korean Surg Soc. 2011, 80: 367-372. 10.4174/jkss.2011.80.5.367.PubMed CentralView ArticlePubMedGoogle Scholar
- Mysorekar VV, Rao SG, Jalihal U, Sridhar M: Schwannoma of the ascending colon. Indian J Pathol Microbiol. 2010, 53: 198-200. 10.4103/0377-4929.59241.View ArticlePubMedGoogle Scholar
- Min YW, Kim YH, Yun HS, Kil JS, Kim YC, Yun SH, Kim KM, Kim JJ: A case of benign schwannoma in the ascending colon. Korean J Gastroenterol. 2007, 50: 398-401.PubMedGoogle Scholar
- Ozawa T, Watanabe H, Okuyama Y, Okumura K, Tsuchiya T, Tanji N, Anzai Y, Unakami M: [A case of schwannoma of ascending colon.]. Nihon Shokakibyo Gakkai Zasshi. 2001, 98: 167-173.PubMedGoogle Scholar
- Wani HU, Al Omair A, Al Shakweer W, Ahmed B: Schwannoma of the ascending colon with ileocolic intussusception. Trop Gastroenterol. 2010, 31: 337-339.PubMedGoogle Scholar
- Suh SW, Park JM, Choi YS, Cha SJ, Chang IT, Kim BG: Laparoscopic approach to a case of appendicular schwannoma. J Korean Soc Coloproctol. 2010, 26: 302-306. 10.3393/jksc.2010.26.4.302.PubMed CentralView ArticlePubMedGoogle Scholar
- Levy AD, Quiles AM, Miettinen M, Sobin LH: Gastrointestinal schwannomas: CT features with clinicopathologic correlation. AJR Am J Roentgenol. 2005, 184: 797-802.View ArticlePubMedGoogle Scholar
- Quiroga S, Alvarez-Castells A, Pallisa E, Sebastia MC: Duodenal schwannoma causing gastrointestinal bleeding: helical CT findings. Abdom Imaging. 1997, 22: 154-155. 10.1007/s002619900160.View ArticlePubMedGoogle Scholar
- Rueda O, Escribano J, Vicente JM, Garcia F, Villeta R: Gastrointestinal autonomic nerve tumors (plexosarcomas). Is a radiological diagnosis possible?. Eur Radiol. 1998, 8: 458-460. 10.1007/s003300050413.View ArticlePubMedGoogle Scholar
- Okada N, Hirooka Y, Itoh A, Hashimoto S, Niwa K, Ishikawa H, Itoh T, Kawashima H, Goto H: Retroperitoneal neurilemoma diagnosed by EUS-guided FNA. Gastrointest Endosc. 2003, 57: 790-792. 10.1067/mge.2003.216.View ArticlePubMedGoogle Scholar
- Stelow EB, Lai R, Bardales RH, Linzie BM, Mallery S, Stanley MW: Endoscopic ultrasound-guided fine-needle aspiration cytology of peripheral nerve-sheath tumors. Diagn Cytopathol. 2004, 30: 172-177. 10.1002/dc.10274.View ArticlePubMedGoogle Scholar
- Larghi A, Noffsinger A, Dye CE, Hart J, Waxman I: EUS-guided fine needle tissue acquisition by using high negative pressure suction for the evaluation of solid masses: a pilot study. Gastrointest Endosc. 2005, 62: 768-774. 10.1016/j.gie.2005.05.014.View ArticlePubMedGoogle Scholar
- Larghi A, Verna EC, Ricci R, Seerden TC, Galasso D, Carnuccio A, Uchida N, Rindi G, Costamagna G: EUS-guided fine-needle tissue acquisition by using a 19-gauge needle in a selected patient population: a prospective study. Gastrointest Endosc. 2011, 74: 504-510. 10.1016/j.gie.2011.05.014.View ArticlePubMedGoogle Scholar
- Skopelitou AS, Mylonakis EP, Charchanti AV, Kappas AM: Cellular neurilemoma (schwannoma) of the descending colon mimicking carcinoma: report of a case. Dis Colon Rectum. 1998, 41: 1193-1196. 10.1007/BF02239444.View ArticlePubMedGoogle Scholar
- Miettinen M, Lasota J: Gastrointestinal stromal tumors–definition, clinical, histological, immunohistochemical, and molecular genetic features and differential diagnosis. Virchows Archiv. 2001, 438: 1-12. 10.1007/s004280000338.View ArticlePubMedGoogle Scholar
- Miettinen M, Shekitka KM, Sobin LH: Schwannomas in the colon and rectum: a clinicopathologic and immunohistochemical study of 20 cases. Am J Surg Pathol. 2001, 25: 846-855. 10.1097/00000478-200107000-00002.View ArticlePubMedGoogle Scholar
- Maciejewski A, Lange D, Wloch J: Case report of schwannoma of the rectum–clinical and pathological contribution. Med Sci Monit. 2000, 6: 779-782.PubMedGoogle Scholar
- Pollock J, Morgan D, Denobile J, Williams J: Adjuvant radiotherapy for gastrointestinal stromal tumor of the rectum. Dig Dis Sci. 2001, 46: 268-272. 10.1023/A:1005581000712.View ArticlePubMedGoogle Scholar
- Wilhelm D, von Delius S, Weber L, Meining A, Schneider A, Friess H, Schmid RM, Frimberger E, Feussner H: Combined laparoscopic-endoscopic resections of colorectal polyps: 10-year experience and follow-up. Surg Endosc. 2009, 23: 688-693. 10.1007/s00464-008-0282-5.View ArticlePubMedGoogle Scholar
- Teitelbaum EN, Nguyen SQ, Zhu H, Salky BA: Laparoscopic resection of a schwannoma of the ascending colon. Am Surg. 2010, 76: E97-E99.PubMedGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.