An unusual case of anaplastic lymphoma kinase-positive large B-cell lymphoma in an elderly patient: A case report and discussion.

We present an unusual case of anaplastic lymphoma kinase (ALK)-positive large B-cell lymphoma, with rapid clinical progression, which occurred in a 90-year-old male patient. The patient presented with numerous enlarged lymph nodes in the neck and mediastinum. Histopathological analysis of a single lymph node detected diffuse large immunoblastic- or plasmablastic-like tumor cells, which were strongly immunoreactive for ALK in a granular cytoplasmic distribution, but negative for the expression of CD20 and CD79a. In addition, polymerase chain reaction assays were unable to detect clonal rearrangements of the T cell receptor-γ and immunoglobulin heavy chain genes in the tumor lesion, and in situ hybridization tested negative for infection with Epstein-Barr virus. The patient underwent a single cycle of chemotherapy using the cyclophosphamide, doxorubicin, vincristine, prednisone, and etoposide (E-CHOP) regimen; however, the patient developed pleural effusions with respiratory distress, associated with clinical deterioration. The patient succumbed to the disease within 4 months of initial presentation. To the best of our knowledge, this is the eldest patient with this type of lymphoma to be reported in the literature.