The relapse of acute lymphoblastic leukemia (ALL) usually involves the bone marrow, with the central nervous system being the most frequent extramedullary site. The relapse of ALL in the female genital organs, particularly the uterus, is markedly rare. We report such a patient who developed relapse in the bone marrow and uterus. The uterine lesion, which presented as abnormal uterine bleeding, consisted of a mass on MRI and proliferation of ALL cells on histology. MRI revealed a heterogeneous high-intensity mass (T2-WI/D-WI) with a diameter of 6.8 cm, a notable decrease in the apparent diffusion coefficient (ADC), and mild enhancement by contrast enhancement study. Histological findings of the uterine cervix demonstrated the infiltration of ALL. The patient achieved remission by allogeneic haplo-identical hematopoietic stem-cell transplantation, but died of complications of the transplantation. This case suggested that attention should be paid to the uterus as a site of extramedullary relapse. In addition, abnormal uterine bleeding, which is a common sign of hormonal imbalance and hormone replacement therapy after chemotherapy, may be an initial sign of extramedullary recurrence. To confirm uterine relapse as an intractable disease, the accumulation of more cases is required.
Keywords: MRI features; Philadelphia-negative B-ALL; refractory clinical course; uterine relapse.