The Ottawa Hospital, University of Ottawa Faculty of Medicine, Ottawa, Ontario Correspondence: Dr Tushar Shukla, University of Ottawa, Faculty of Medicine, 451 Smyth Road, Ottawa, Ontario K1H 8L6. Telephone 613-737-8899, fax 613-737-8599, e-mail tshuk078@uottawa.ca Received for publication October 5, 2013. Accepted October 10, 2013 Case Presentation A 57-year-old woman, with colonic Crohn disease (CD) diagnosed four years previously, presented to the emergency department with a six-week history of severe abdominal pain. She did not have diarrhea. She had inactive perianal fistulas. Laboratory tests at presentation showed an elevated C-reactive protein level of 103 mg/L, and low albumin of 24 g/L. Other bloodwork was unremarkable. Stool testing was negative for Clostridium difficile, and culture and sensitivity. Her medical history was significant for rheumatoid arthritis (RA). She had been receiving infliximab and methotrexate for RA and CD. A computed tomography scan revealed wall thickening in the ascending, transverse and descending colon. No lymphadenopathy was present. Pericolonic inflammatory changes were apparent. No obstruction was present. Colonoscopy at the time of admission, to confirm what appeared to be a CD flare, revealed a benign-appearing ulcerated stricture at 40 cm from the anal verge (Figure 1). The colonoscope could not pass the stricture. There was no active CD in the colon distal to the stricture. The stricture was biopsied. The patient was treated with intravenous solumedrol and, subsequently, prednisone for a presumed CD flare. Steroids led to resolution of her pain. Biopsies of the stricture unexpectedly revealed an anaplastic large cell lymphoma (ALCL) (Figure 2). Infliximab and methotrexate were discontinued. A bone marrow biopsy was negative for lymphoma and computed tomography enterography showed a normal small bowel. The patient successfully completed six cycles of CHOP (cyclophosphamide, hydroxy doxorubicin, vincristine, prednisone) chemotherapy. Repeat biopsies of the stricture postchemotherapy showed no lymphoma, but atypical cells were present (Figure 3). A tattoo was used to mark the location of the stricture. The stricture was balloon-dilated to allow visualization of the proximal colon. There was only a single, discrete patch of ulceration in the ascending colon. Biopsies here were consistent with CD. It was believed that her risk of lymphoma recurrence was high. She was referred for surgical intervention and underwent a left hemicolectomy. Total proctocolectomy and ileostomy were considered. Total proctocolectomy would have reduced the risk of recurrent CD, which would be difficult to manage given uncertainties about reinitiating immunomodulators or biologics in a patient with treated lymphoma. The patient believed she would not be able to manage a stoma due to debility from RA. Subtotal colectomy and ileorectal anastomosis was considered, but the concern was that this might worsen her perianal disease due to looser bowel movements. Pathology of the resected colon showed the ulcerated stricture, but no lymphoma or malignancy. Thirty-one lymph nodes were negative for malignancy. The patient is well, and not taking biologics and immunomodulators eight months postoperatively. Colonoscopy eight months postoperatively revealed a patch of mild ulceration at 50 cm from the anal verge. Biopsies were consistent with CD. There is no evidence of lymphoma recurrence.