Multifocal Extramedullary Relapse With Neuroleukemiosis in a Case of Early T-Cell Precursor ALL: 18F-FDG PET/CT Findings.

ABSTRACT: Early T-cell precursor ALL (acute lymphoblastic leukemia) is a rare type of childhood and adult T-cell ALL. Disease recurrence is common within 2 years from the time of initial diagnosis. Outcomes of relapse have been characterized through risk stratification schemes, and one of the major determinants of overall survival is the overall tumor burden and sites of relapse. Although testicular recurrence is common; Peripheral nerve as a site of recurrence is relatively rare. We present a case of early T-cell ALL on maintenance therapy with multifocal relapse on FDG PET/CT in the cervical lymph nodes, the testis, and the left sciatic nerve. Bone marrow and flow cytometry confirmed the relapse.