A case of myelodysplastic syndrome complicated by pulmonary alveolar proteinosis with a high serum KL-6 level

Serious hematological diseases often cause respiratory disorders. Because t hese are related to the Prognoses of patients with hematological diseases, their early diagnosis is necessary. This study describes a 6-year-old girl with myelodysplastic syndrome complicated by pulmonary alveolar proteinosis who showed a remarkable increase in her serum KL-6 level. Three years and 2 months after the end of therapy for neonatal melanoma, a diagnosis of mye lodysplastic syndrome with leukemic change was made. Ten months after the o nset of leukemia, she had respiratory distress with an increased serum KL-6 level of 75,000 U/mL (reference range; <500 U/mL). Despite various treatme nts for pulmonary complications, she died 3 months after developing respira tory distress. A diagnosis of pul,nonary alveolar proteinosis was made at a utopsy. Earlier treatment of respiratory distress could be achieved if seru m KL-6 levels were examined earlier.