Abstract
Primary central nervous system (CNS) ALK-negative anaplastic large cell lymphoma (ALCL) is a rare and enigmatic disease, with limited data available in the literature. This case report adds to the existing body of knowledge by describing a unique case of a 68-year-old, immunocompetent male who presented with a single ring-enhancing lesion, which upon further analysis proved to be an ALK-negative ALCL that was primary to the CNS. A comprehensive review of the existing literature is provided, highlighting the genetic characteristics and diverse neuroimaging findings of this disease entity. This report adds valuable information to the understanding of this rare disorder, and highlights the need for further research in the field of primary CNS ALK-negative ALCL.