Pulmonary Leukocytoclastic Vasculitis as an Initial Presentation of Myelodysplastic Syndrome.

Systemic vasculitis involving the lung is a rare manifestation of myelodysplastic syndrome (MDS), and secondary vasculitis is considered to have poor prognosis. A 44-year-old man presented with fever and dyspnea of 1 month duration. A chest radiograph revealed bilateral multiple wedge shaped consolidations. In addition, the results of a percutaneous needle biopsy for non-resolving pneumonia were compatible with pulmonary vasculitis. Bone marrow biopsy was performed due to the persistence of unexplained anemia and the patient was diagnosed with MDS. We reported a case of secondary vasculitis presenting as non-resolving pneumonia, later diagnosed as paraneoplastic syndrome of undiagnosed MDS. The cytopenia and vasculitis improved after a short course of glucocorticoid treatment, and there was no recurrence despite the progression of underlying MDS.