Pancytopenia with Mediastinal Mass: Clinically Challenging at Times

Ineffective erythropoiesis (IE), occurring during chronic bone marrow failure (chronic hemolytic conditions or bone marrow infiltration by neoplastic or fibrotic tissue), results in several compensatory mechanisms, such as erythroid marrow expansion and extramedullary hematopoiesis (EMH). EMH can involve different body organs. We report on a 16-year-old male, previously known to have thalassemia minor, who was admitted with chest tightness and dry cough. He was found to have right-sided pleural effusion and hepatosplenomegaly. The full blood count demonstrated mild pancytopenia. Computed tomography (CT) scan demonstrated the presence of right-sided pleural effusion and a paramediastinal mass. The initial clinical impression was mainly lymphoma. CT-guided needle biopsy of the paramediastinal mass revealed trilineage hematopoiesis with marked erythroid hyperplasia, consistent with EMH. Hemoglobin electrophoresis was consistent with thalassemia intermedia. This illustrates how the presence of EMH can be clinically misleading.