26. An ATIC::ALK fusion created by balanced insertion rather than inversion of chromosome 2 in an ALK+ anaplastic large cell lymphoma

ALK+ anaplastic large cell lymphoma (ALCL) is a mature T-cell lymphoma with NPM1::ALK fusion or a variant ALK rearrangement. Immunophenotyping including ALK, morphology, and clinical studies including imaging, are generally considered adequate for diagnosis. While specific ALK fusion partners do not appear to have prognostic significance, they may influence the efficacy of ALK inhibitor therapies. We report a case of an 18-year-old male with a right cranio-orbital bone mass. The CD30/CD4/CD45 positive pleomorphic neoplastic cells expressed diffuse cytoplasmic ALK, overall consistent with an ALK+ ALCL, most likely with non-NPM1 partner.