An unusual presentation of primary myelofibrosis.

Extramedullary hematopoisis (EMH) normally occurs in fetal life, but it is pathological in later life and most of the time because of underlying marrow diseases. Sometimes EMH tissue can present with large masses which can cause compressive and constitutional symptoms. They can be wrongly diagnosed as malignancy and pulmonary tuberculosis. Here in this case report we are reporting a case with mediastinal EMH because of underlying mylofibrosis.