Primary peripheral T-cell lymphoma of the colon mimics inflammatory bowel disease: a potential pitfall with F-18 FDG PET/CT imaging.

We present a case of a woman with ulcerative colitis who was referred for an F-18 FDG PET/CT after a suspicious colonoscopy and biopsy. PET/CT showed multiple elongated foci of intense FDG uptake in the colon, a pattern commonly reported with inflammatory bowel disease; however, the possibility of lymphoma was raised. Reevaluation of the biopsies with immunohistochemistry and molecular studies revealed a peripheral T-cell lymphoma and the patient was treated with a total colectomy. In this case, F-18 FDG PET/CT was very useful in determining the extent of the disease. This case also highlights a potential pitfall whereby the tubular and multifocal appearance of this lymphoma subtype can mimic the appearance of bowel involved by inflammatory bowel disease especially on novel techniques such as PET/CT enterography and PET/CT colonography.