Intrathoracic extramedullary hematopoiesis in a case of hereditary spherocytosis

Abstract

A 62-year-old man with a history of hereditary spherocytosis had an abnormal shadow on a chest X-ray film, but the shadow was not examined further. The patient was admitted to our hospital because of severe anemia, multiple gallstones, and splenomegaly. Acute cholecystitis developed due to gallstones. A smear of peripheral blood showed spherocytosis, and the osmotic fragility as measured by Parpart's method was abnormally high. These findings are consistent with hereditary spherocytosis. Splenectomy and cholecystectomy were done. The chest X-ray film, CT scan, and MRI revealed multiple well-demarcatd paravertebral masses. A biopsy of a mediastinal mass was done with an ultrasonically guided needle, and hyperplasic erythroid hemopoietic tissue was obtained. This finding led to the diagnosis of extramedullary hematopoeisis. We think extramedullary hematopoeisis should be included in the differential diagnosis of posterior mediastinal masses.