Delayed diagnosis of a high-grade B-cell non-Hodgkin's lymphoma presenting as an obstructing rectal mass.

This case describes a 54-year-old man who presented to the surgical triage unit and was found to have a rare underlying rectal lymphoma. The patient had previously sought medical advice on multiple occasions, reporting a chronic inability to open his bowels. This case report aims to highlight the importance of thorough history taking and examination, in order to reduce delaying the diagnosis of significant pathology.