Current Thoracic Surgery

Extramedullary hematopoiesis (EMH) is a condition that usually coexists with hematological disorders and rarely causes mass formation. It can occur anywhere in the body, but very rarely becomes a tumorlike mass in the posterior mediastinum and paravertebral region. A 41-year-old female patient presented with respiratory distress. Radiologically, multiple large mass lesions were detected in the posterior mediastinum, localized bilaterally at paravertebral regions. Diagnostic studies with transthoracic biopsy specimen were showed that the mass lesion was consisting of myelocytes, lymphocytes, erythrocytes and megakaryocytes, so the case was reported as EMH. The case was presented to make a differential diagnosis, because it mimics solid neoplasms at unusual localizations, and may accompany hematological disorders.