TY - JOUR T1 - Unusual case of multiple pleural masses JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p2837 AU - Venu Sirpa AU - Parthipan Kanthapillai Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p2837.abstract N2 - A 80 year old lady was referred for evaluation of multiple pleural shadows. She was diagnosed to have myasthenia gravis 30 years ago and was treated with azathioprine until now. Six years ago she underwent bone marrow biopsy for investigation of anemia which revealed hypoplastic marrow with specific red cell aplasia including features consistent with azathioprine treatment.Her hemoglobin was 11.5gm/dl. CT scan of the chest revealed multiple pleural masses. CT guided biopsy of the pleura showed bone marrow with apparently normal granulocytes, normoblasts, megakaryocytes and other myeloid elements. There was no evidence of leukemia or malignancy noted. There was no pleural or pulmonary tissue identified in the biopsy and the features were consistent with extra medullary hemopoiesis (EMH).EMH is the proliferation of blood elements outside the bone marrow cavity. This mainly involves reticuloendothelial system (liver, spleen & lymph nodes) but is also known to occur in every organ of the body including thyroid, pericardium, kidney and lungs. Only a few cases of intra thoracic EMH have been reported in literature. These may manifest as paraosseus masses, pleural masses or haemothorax either alone or in combination. They occur characteristically either unilaterally or bilaterally in the posterior mediastinum. They present as rounded soft tissue opacities paravertebrally with a clear cut outline. Neither calcification nor bony erosion has been reported in these masses. EMH thus forms one of the important differential diagnoses of posterior mediastinal masses. This case illustrates the importance of considering EMH in the differential diagnosis of multiple pleural masses. ER -