Cerebral embolism through hematogenous dissemination of pulmonary mucormycosis complicating relapsed leukemia

Invasive mucormycosis in patients with hematological diseases mostly occurs in the lungs. Invasive mucormycosis of other anatomical sites is relatively infrequent and its pathogenesis has not so far been well elucidated. Here, we describe an autopsy case of pulmonary invasive mucormycosis complicated by cerebral embolism with infarct. A 77-year-old Japanese woman with relapsed acute myeloid leukemia complained of left visual disturbance and weakness of the lower limbs. The diagnosis of leukemic infiltration to the central nervous system was made. Repeated intrathecal injection of methotrexate plus cytarabine resulted in partial amelioration of the neurologic symptoms. However, the patient then developed fever, dyspnea, and subsequent right hemiparesis. A computed tomography (CT) scan showed a consolidative shadow with halo sign in the left lung field, which was compatible with either invasive pulmonary aspergillosis or mucormycosis. These findings accounted for fever and dyspnea, but not hemiparesis. Despite antifungal therapy, the patient succumbed to death after two weeks. Autopsy revealed pulmonary invasive mucormycosis with a fungal ball in the lumina of the adjacent ascending aorta. Intriguingly, autopsy and postmortem CT scan identified left cerebral infarct due to mucormycosis, which accounted for the right hemiparesis. It is likely that the fungal ball caused the cerebral embolism through hematogenous dissemination. We should suspect hematogenous dissemination when we see a patient with pulmonary invasive mucormycosis developing neurologic symptoms.