A 37-year-old woman with an incidentally found mediastinal nodule

Thoracic splenosis: know it--avoid unnecessary investigations, interventions, and thoracotomy

Thoracic splenosis (TS) is autoimplantation of ectopic splenic tissue in the thoracic cavity that occurs following splenic injury. Most cases of TS are asymptomatic and are diagnosed during the course of an evaluation of incidentally discovered pulmonary lesions. Some cases may be difficult to diagnose, especially if features suggesting TS are not recognized. This may lead to an extensive workup and unnecessary invasive diagnostic procedures including thoracotomy. Multiple, asymptomatic, left-sided pleura-based lesions associated with a history of thoracoabdominal injury and splenectomy are the key points that should alert one to suspect TS, which can then simply be confirmed with a (99m)Tcsulfa colloid radionuclide scan. If TS is suspected and radionuclide imaging studies are performed, further extensive investigations, such as bronchoscopy, biopsy, thoracoscopy, and thoracotomy, are not required as the radionuclide scan is definitive for diagnosis. Most cases are asymptomatic, so further treatment is rarely required; all cases are managed conservatively. We emphasize that all physicians, radiologists, pathologists, and interventionalists should recognize key features that suggest the diagnosis of TS, order appropriate imaging when it is suspected, and avoid unnecessary invasive diagnostic procedures including thoracotomy.