Primary renal lymphoma: a comprehensive review of the pathophysiology, clinical presentation, imaging features, management and prognosis.

Primary renal lymphoma (PRL) is defined as a non-Hodgkin's lymphoma restricted to kidneys with the absence of extensive nodal disease. It is an exceedingly rare clinicopathological entity, accounting for 0.7% of extranodal lymphomas. Published medical literature regarding the natural history and clinical outcomes of PRL remains limited. We describe a case of a young patient who presented with left shoulder pain, continuous fever, and unexplained weight loss as atypical initial manifestations of bilateral PRL, confirmed with the standard set of investigations. Furthermore, this article reviews the literature and discusses various aspects of PRL, including pathophysiology, presentation patterns, imaging and pathological characteristics, management, and prognosis. This paper serves to provide an update and aims to enhance the understanding of PRL. Timely diagnosis and treatment are imperative to achieve improved outcomes. Clinicians should maintain a high index of suspicion in order to prevent morbidity and mortality associated with this serious disease. © BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.