Diffuse large B-cell lymphoma arising primarily at the stoma after bladder reconstruction using ileal conduit.

A 76-year-old man suffered from swelling stoma for several weeks. A biopsy sample revealed the diffuse infiltration of large lymphoid cells which were positive for CD20, bcl-6, and MUM1. The patient was diagnosed with diffuse large B-cell lymphoma, with a non-germinal center B-cell pattern. A whole-body PET-CT scan revealed that the lymphoma was restricted to the stomal site. Bladder reconstruction was undertaken using the ileal conduit: this is the first reported case of lymphoma that developed primarily at the stoma. During the long-term maintenance after bladder reconstruction, clinicians should consider the possibility of lymphoma at the stomal site.