[Extramedullary hematopoiesis as differential mediastinal space-occupying lesion diagnosis].

Intrathoracic extramedullary hematopoiesis is a rare disease in the differential diagnosis of mediastinal masses. It is suggested that asymptomatic masses should not be treated. A correct diagnosis can thus help to avoid an operation. The aim of this case report is to draw attention to this phenomenon as a cause of mediastinal masses and to provide information about diagnostic facilities available. We report the case of a 53-year-old male patient with hereditary spherocytosis as well as the case of a 59-year-old male patient with pyruvate kinase deficiency who showed intrathoracic paravertebral masses, that were identified in the first case by video-assisted thoracoscopic intervention (VATS) and in the second case by thoracotomy as a region of extramedullary hematopoiesis.