Thoracic splenosis: A diagnosis by history and imaging

Thoracic splenosis (TS) is autoimplantation of ectopic splenic tissue in the thoracic cavity that occurs following splenic injury. The majority of cases of TS are asymptomatic and are diagnosed in 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 work-up and unnecessary invasive diagnostic procedures including thoracotomy. This case report describes a 40-year-old man, who was diagnosed incidentally with TS, several years after the initial injury. Multiple, asymptomatic, left-sided pleural based lesions associated with a history of thoracoabdominal injury and splenectomy are the key points that should alert suspicion of TS, which can then simply be confirmed by a Tc-99m sulphur colloid radionuclide scan. Most patients are treated conservatively unless they are symptomatic. Physicians must recognize the key features suggesting a diagnosis of TS, order appropriate imaging studies and avoid unnecessary invasive diagnostic procedures.