Cytodiagnosis of extramedullary hematopoiesis in serous effusion: A rare presentation unfolding the underlying etiology

Extramedullary hematopoiesis (EMH) usually involves reticuloendothelial system. However, it rarely may be present in the serous body effusions. In our case, the fluid cytology of both peritoneal and pleural fluid was diagnostic of the EMH in a patient with an undiagnosed underlying etiology.