Mycobacterium avium Complex Pulmonary Disease as a Clinical Signal of Host Vulnerability in Advanced Myelofibrosis.

An 82-year-old woman with JAK2-mutated myelofibrosis who developed hemoptysis after initiation of ruxolitinib. She presented with anemia and ground-glass opacities and was treated with antibiotics. She was readmitted with worsening respiratory symptoms. Sputum cultures yielded Mycobacterium avium. Her clinical course was complicated by leukocytosis with blasts prior to death.