Primary colonic Hodgkin’s lymphoma masquerading as Crohn’s disease

Abstract

Primary gastrointestinal (GI) Hodgkin's disease (HD) is rare, representing less than 0.5% of cases of HD. This is a case of primary colonic HD that was treated as Crohn's disease (CD) for 3 years until the diagnosis of lymphoma was made. A 32 year-old man presented in 1999 with diarrhea and melena. He was diagnosed with CD based on colonoscopy with biopsies. He was managed medically, and did well for a year when he had increased diarrhea. Colonoscopy showed worsened colitis. The patient did not tolerate immunosuppressants, and on Pentasa, his diarrhea improved. In early 2002, he complained of fatigue, abdominal distention and anorexia. CT scan demonstrated small bowel and colonic wall thickening. He was treated for iron and B12 deficient anemia. In June 2002, his symptoms worsened and he was referred to our institution. Exam revealed a cachectic, afebrile male with marked abdominal distention and a large tender palpable mass in the mid abdomen. There was no lymphadenopathy. Laboratory data included WBC 20, HCT 16.6, Platelets 680, albumin <1, and normal liver enzymes. Bone marrow biopsy was negative for lymphoma, and HIV test was negative. CT showed a large mass defining the wall of the ascending colon and terminal ileum with bulky mesenteric lymphadenopathy. Colonoscopy revealed a normal left colon and a 20cm long area in the right colon that was markedly dilated with irregular, erythematous mucosa with ulceration and areas of necrosis. Biopsies demonstrated numerous large, atypical cells, and scattered Reed-Sternberg cells, staining positive for CD 15 and 30. The diagnosis of Hodgkin's lymphoma was made. The patient underwent hemicolectomy and was found to have a mass involving the terminal ileum and right colon. The mesentery was replaced completely by tumor. Pleural fluid contained Reed-Sternberg cells and he was treated for stage IV HD with chemotherapy. He never achieved complete remission, and 8 months after diagnosis was found to have progression of disease. Retrospective review of biopsies from the patient's initial colonoscopies shows nonspecific colitis with mild chronic changes. Deeper sections show rare Reed-Sternberg cells, making HD the patient's primary diagnosis. There are few reports in the literature of primary HD mimicking inflammatory bowel disease (IBD). In our case, we were able to demonstrate that HD was present all along. Primary colonic lymphoma is rare, but should be considered in the differential of IBD, especially with atypical or refractory behavior.