The Pulmonary Complications of Paraneoplastic Autoimmune Vasculitis in a Patient With Myelodysplastic Syndrome.

Paraneoplastic autoimmune phenomena may occur in up to 30% of patients with myelodysplastic syndrome (MDS). We present the case of a patient with MDS who developed diffuse alveolar hemorrhage due to paraneoplastic autoimmune vasculitis. The patient was a 55-year-old male who had been referred for outpatient hematology/oncology evaluation by his primary care physician for incidentally discovered thrombocytopenia. When he presented to the clinic, he reported new-onset chills, weakness, and night sweats. He endorsed a 20-pound weight loss over two months as well as two weeks of fatigue, exertional dyspnea, and epistaxis. He was noted to be ill-appearing and had bilateral pitting edema to the knees. Vital signs revealed a temperature of 102.3 °F, oxygen saturation of 84% on room air, and tachycardia to the 90s. Labs showed hemoglobin of 5.7 g/dL, hematocrit of 17.2 g/dL, and platelet count of 27 kµL. He was admitted to the hospital for blood and platelet transfusions, empiric antibiotics, and further diagnostic studies. The peripheral blood smear showed 4% blasts and frequent dyspoietic granulocytes. Bone marrow biopsy (BMB) was performed to differentiate between acute leukemia and myelodysplasia. BMB revealed myelodysplasia with excess blasts and erythroid predominance.During hospitalization, the patient developed acute hypoxemic respiratory failure due to bronchoscopy-confirmed diffuse alveolar hemorrhage from thrombocytopenia. His platelet count was 12 kµL. High-dose corticosteroids (2 mg/kg prednisone) were initiated for suspected paraneoplastic autoimmune vasculitis, pending BMB results. The patient steadily improved, was extubated, and had reduced oxygen and transfusion requirements.High-dose steroids were stopped, and the patient was started on decitabine chemotherapy with the ultimate goal of bone marrow transplantation. On day five of decitabine, the patient developed acute hypoxic respiratory failure requiring intubation as well as hypotension requiring vasopressors. Given that recurrent diffuse alveolar hemorrhage was again suspected, high-dose steroids were resumed upon transfer to the ICU. He continued to decompensate and ultimately experienced ventricular tachycardia requiring three separate episodes of cardiopulmonary resuscitation. Per the family's wishes, he was palliatively extubated, and he expired an hour later. Diffuse alveolar hemorrhage is a rare but potentially deadly pulmonary complication of MDS, stemming from a paraneoplastic autoimmune vasculitis. Patients who initially present with atypical autoimmune phenomena should raise suspicion for an underlying MDS, the presence of which can guide the promptness, extent, and duration of immunosuppressive therapy. Failure to expeditiously treat these patients with corticosteroids can lead to serious complications and death.