Extramedullary hematopoietic tumors of the posterior mediastinum related to asymptomatic refractory anemia.

Two asymptomatic paravertebral thoracic masses occurred in a 65-year-old patient with isolated macrocytosis. The largest one measured 8 cm and was surgically resected with a presumptive diagnosis of schwannoma. This thoracic mass was hemorrhagic, encapsulated, and composed of fat and hematopoietic tissue. While extramedullary hematopoietic tumors usually occur in patients with severe chronic hemolytic anemia, our report suggests that such lesions must be considered in the differential diagnosis of posterior mediastinal mass in patients without clinical evident anemia.