Thoracic splenosis. Report of a case and review of the diagnostic workup

UNLABELLED: Splenosis is the autoimplantation of splenic tissue to ectopic sites after spleen injury. Although splenosis most commonly occurs in the abdomen, it may occur in the thorax in case of diaphragm rupture. Thoracic splenosis (TS) is often asymptomatic and is diagnosed incidentally in the course of chest examination. We describe the case of a man, with a history of thoracoabdominal trauma, undergoing routine chest radiography with the evidence of radio-opaque images close to the inferior left curvature of the cardiac shadow, which resulted to be nodules of TS at the contrast enhanced CT scan. CT scan or MRI and an accurate anamnesis are usually sufficient to diagnose TS, otherwise scintigraphy with 99mTc is needed. Imaging-guided biopsy and thoracoscopy should be performed if scintigraphy is unavailable or results are inconclusive. It is not usually necessary to remove the TS because the splenic tissue is slow growing, non-invasive and benign. Rarely surgery may be required for symptomatic TS (hemoptysis, cough or pleuritic chest pain). TS may be difficult to diagnose, especially if features suggesting TS are not recognized and the anamnesis in not known. This may lead to an extensive work-up and unnecessary invasive diagnostic procedures (including biopsy, thoracoscopy, up to thoracotomy). In the workup of thoracic nodules TS should be considered in patients with a history of trauma and spleen injury.KEY WORDS: Thoracic splenosis, Spleen, Mediastinal nodules, Thoracoabdominal trauma.