Bowel perforation from occult ileal involvement after diagnosis in a case of primary mediastinal large B-cell lymphoma.

Primary mediastinal large B-cell lymphoma (PMBCL) is confined to the mediastinum or contiguous nodal areas in most cases. Extramediastinal and abdominal involvement, especially at diagnosis, is extremely rare. Our case describes the first case of histologically proven ileal involvement of PMBCL at diagnosis that led to ileal perforation. Positron emission tomography CT could increase the sensitivity of staging by detecting unusual sites of disease localisation, and could impact clinical management.