Unusual presentation of myelofibrosis.

摘要

A 78-year-old man presented with a 4-month history of progressive fatigue and shortness of breath. There was no history of fever, chest pain or haemoptysis. His medical history was negative for tuberculosis, chronic obstructive pulmonary disease or any blood dyscrasias. He had a history of 24 pack-years of smoking, quitting 20 years ago. On presentation, he was tachypneic and had severe pallor. There was no significant lymph node enlargement. Examination of his chest showed absence of air entry in the middle and lower zones on the left side and showed dullness on percussion. His abdomen was soft with a palpablespleen 7 cm below the left costal margin. Laboratory tests showed haemoglobin to be 60 g/L and a white blood cell count of 21.5 x 10~9/L with differential count of myelocytes5%, metamyelocytes 14%, band forms 22%, neutrophils35%, lymphocytes 18% and eosinophils 6%. Platelet count was 30 x 10~9/L. Peripheral blood smear showed a leucoerythroblastic picture (teardrop cells, anisocytes,polychromasiaand nucleated red blood cells). His serum lactate dehydrogenase was 2450 U/L (normal range 110-230 U/L). Chest radiograph showed a left-sided pleuraleffusion extending up to mid-zone. He underwent thoracocentesis, which yielded haemorrhagic fluid.Laboratory findings were consistent with exudative pleuraleffusion, with initial exfoliate cytology showing atypical cells. There was a strong suspicion of carcinoma of lung with metastasis to bone marrow. Subsequently, he underwent pleural biopsy, which showed a dense infiltrate of lymphocytes, immature granulocytes, neutrophils, histiocytesand many eosinophils with occasional megakaryocytes.A bone marrow aspirate yielded a dry tap and trephine biopsy showed medullary fibrosis, dysplastic-megakaryocyte hyperpfasia and osteosclerosis suggestive of myelofibrosis. A silver staining of bone marrow showed moderate to severe collagen fibrosis. He was started on 500 mg b.i.d. On hydroxyurea, he required repeated thoracocentesisfor symptomatic pleural effusion. His anaemia was refractory to treatment requiring blood transfusion every 3-4 weeks. The patient died 30 months after the initial diagnosis.