Diffuse Alveolar Hemorrhage Leading to Respiratory Failure in Mixed Phenotype Acute Leukemia: A Fatal Pulmonary Complication.

Mixed phenotype acute leukemia (MPAL) is a rare and diagnostically challenging hematologic malignancy characterized by the co-expression of myeloid and lymphoid lineage markers. We present the case of a 61-year-old woman with newly diagnosed MPAL who developed diffuse alveolar hemorrhage (DAH) shortly after induction chemotherapy. Despite aggressive supportive care, including bronchoscopy-guided diagnosis, high-dose corticosteroids, antifibrinolytics, and lung-protective ventilation with prone positioning, her condition rapidly deteriorated into multi-organ failure and death. This case highlights the need for early recognition of pulmonary complications in high-risk leukemias and underscores the limitations of current management strategies in the setting of DAH complicating MPAL.