Fine needle aspiration diagnosis of extramedullary hematopoiesis resembling mediastinal and paravesical tumors. A report of 2 cases

BACKGROUND: Extramedullary hematopoiesis is a compensatory phenomenon that occurs when normal function of the bone marrow is disturbed. It is most often seen in patients with hematologic disorders. Although the sites most frequently involved are the spleen, liver and lymph nodes, other organs may be involved. We report on 2 cases of extra-medullary hematopoiesis mimicking posterior mediastinum and paravesical tumors and diagnosed by fine needle aspiration cytology. CASES: Two men, aged 72 and 82 years, with hemolytic anemia (thalassemia intermedia and idiopathic) presented with solid masses involving the posterior mediastinum and paravesical region. The patients underwent computed tomography-guided fine needle aspiration. The smears were composed of normal bone marrow elements. Both cases were diagnosed as extramedullary hematopoiesis. CONCLUSION: Fine needle aspiration cytology is an useful method of diagnosing extramedullary hematopoiesis and aids in planning treatment.