Idiopathic myelofibrosis associated with classic polyarteritis nodosa.

A woman with scleroderma and classic polyarteritis nodosa (PAN) who developed idiopathic myelofibrosis (IM) is reported. The patient presented with a one-year history of weakness, polyarthritis, Raynaud phenomenon, dry cough, and epigastralgia. The diagnosis of scleroderma with visceral involvement was made and treatment with prednisone subsequently started, with good clinical response. Six years later, fever, weight loss, livedo reticularis, and dysesthesias developed. Electromyographic studies were consistent with sensory neuropathy and a sural nerve biopsy yielded the diagnosis of PAN. The patient received cyclophosphamide plus prednisone with a favorable response, but 11 years later she was admitted because of weakness, constitutional symptoms, and abdominal pain due to spleen infarcts. Marked anemia, with aniso-poikilocytosis, tear-drop cells, immature myeloid precursors in the peripheral blood, and an increased serum LDH, was observed and the diagnosis of IM established by bone marrow biopsy. This case represents a new association between IM and an autoimmune disease and supports the hypothesis of an immune basis of IM in some patients.