Spine Thoracic splenosis mimicking thoracic schwannoma: case report and review of the literature Ali M. Alaraj, MD a , Roukoz B. Chamoun, MD a , Nader S. Dahdaleh, MD a , Pierre M. Sfeir, MD b , Mohamad S. Miski,MD c ,Zaher K.Otrock,MD a , Ghassan S. Skaf,MD, FRCSC a, * a Division of Neurosurgery and b Division of Cardiothoracic Surgery, Department of Surgery and c Department of Pathology, American University of Beirut Medical Center, Beirut 1107 2020, Lebanon Received 16 June 2004; revised 4 October 2004; accepted 8 November 2004 Abstract Background: Thoracic splenosis is a rare entity. It occurs sometime after splenic and diaphragmatic injury,and it is rarely symptomatic. Case Description: We report a case of leftupperthoracic paraspinal splenosis 25 years after a thoracoabdominal penetrating trauma that required a splenectomy. The pathology was suspected on a routine chest x-ray and it mimicked a schwannoma on magnetic resonance imaging. Less than 40 cases of thoracic splenosis were described in the literature, butfew were misinterpreted as schwannoma. Conclusion:Alertness to the possibility of thoracic splenosis can lead to confirmation of the diagnosis with technetium Tc 99m–tagged red blood cell radionuclide scanning based on a previous history of traumatic splenectomy. D 2005 Elsevier Inc. All rights reserved. Keywords: Thoracic lesions; Splenosis; Schwannoma 1. Introduction Splenosis is a term used to describe autotransplantation of splenic tissues. It occurs usually in the abdominal cavity aftertraumatic ruptureof the spleen and isdiagnosed severalyearsafterthe trauma.Thoracicsplenosisis described less often and it occurs only when the splenic tissue migrates through an injured diaphragm. Usually, it is asymptomatic and is diagnosed on routine chest radiogra- phy.We reporta caseof thoracicsplenosisthatwas diagnosed on routine chest x-ray 25 years after a gunshot wound to the abdomen that resulted in a ruptured spleen and was misinterpreted as a thoracic schwannoma. Recent imaging techniques may allow a firm diagnosisto be reached by noninvasive methods. 2. Case presentation A 42-year-old male patient was referred to the Spine Section ofthe Division of Neurosurgery at the American University of Beirut Medical Center, Beirut, Lebanon, with a large left paraspinal upper thoracic mass discovered on routine chest x-ray as an ill-defined density over the left pulmonary apex (Fig. 1).Further evaluation with magnetic resonance imaging (MRI) revealed a mass that measured 6.5 5.5 2.5 cm nearthe neural foramen of T3. It showed high signal intensity on T2- and low on T1-weighted images (Figs. 2-4). The mass showed minim enhancement afterintravenous gadolinium administration and was interpreted as upper thoracic schwannoma with major extraforaminal component. In his pastsurgicalhistory,the patientsustained a gunshot wound to the left side ofthe upper abdomen 25 yearsearlier,which resulted in splenic rupture, colonic splenic flexure perforation, and gastric injury. A review of his old medicalrecordsshowedthathe underwent a splenectomyand colostomyfollowed by subsequent colostomy closure at a laterstage, butno detailed report 0090-3019/$ – see front matter D 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.surneu.2004.11.005 * Corresponding author. Division of Neurosurgery, Department of Surgery, American University of BeirutMedicalCenter,Riad El-Solh, Beirut1107 2020,PO Box 11-0236,Beirut-Lebanon. Tel.: +961 1 350000x5269; fax: +961 1 363291. E-mail address: gskaf@aub.edu.lb (G.S. Skaf). Surgical Neurology 64 (2005) 185 – 188 www.surgicalneurology-online.com