A case report: thoracic extramedullary hematopoiesis found by occurring spontaneous pneumothorax.

Extramedullary hematopoiesis (EMH) is a rare disease associated with hematologic disorders. This report describes a case of posterior mediastinal mass found by occurring spontaneous pneumothorax in a 48-year-old male. The intrathoracic mass resected using video-assisted thoracic surgery (VATS) was diagnosed thoracic EMH (TEMH). No disorders were found by hematologic exams before or after surgery. This report suggests that such lesions must therefore be considered in the differential diagnosis of posterior mediastinal tumors presenting with no hematologic disorders.