Bilateral Interstitial Pneumonic Shadows Caused by Perivascular Fibrosis and Extramedullary Megakaryopoiesis of the Lung in a Case of Advanced Agnogenic Myeloid Metaplasia and Myelofibrosis

A 59-year-old man with progressive and advanced agnogenic myeloid metaplasia, also called idiopathic myelofibrosis, had complications showing bilateral interstitial pneumonic shadows. Pathological assessment of transbronchial biopsy revealed pulmonary perivascular fibrosis and infiltration of megakaryocytes. Autopsy 3 months later showed extramedullary megakaryopoiesis and fibrosis in lung, pleura, kidney, liver and spleen. Histopathological analysis for platelet-derived growth factor (PDGF) and PDGF-receptor revealed an abnormally high expression of the PDGF-receptor-(beta) gene in pulmonary fibroblasts. This is the first description of an association between pulmonary fibrosis and PDGF in idiopathic myelofibrosis.