A case of diverticular colitis with lesions resembling ulcerative colitis and correlation of tumor necrosis factor-alpha staining with clinical manifestations.

A 45-year-old male with a 3-month history of abdominal pain and melena underwent colonoscopy (CS) at our hospital in May 2009. He was diagnosed with diverticular colitis based on findings of redness around diverticula in the sigmoid colon and biopsy findings of non-specific inflammation. The second CS, which was performed in July 2009 to investigate relapse, showed diffuse redness around diverticula in the sigmoid colon. As seen in active ulcerative colitis (UC), the formation of crypt abscesses was observed in the biopsy. Although the patient was making satisfactory progress after administration of oral mesalazine, CS was performed again in September 2011 because of recurrence of melena, which revealed redness and erosion around diverticula in the ascending and sigmoid colon. Biopsy findings were similar to those of active UC. Immunohistochemical staining of the biopsy specimen with anti-tumor necrosis factor (TNF)-a antibody showed 80 % of lymphocytes were positive for TNF-a compared with 20 % at the first biopsy. The patient's symptoms subsided with an increase in the dose of mesalazine and concurrent administration of prednisolone at 10 mg. He has remained on oral mesalazine and is currently asymptomatic. The findings of this study suggested a correlation between clinical manifestations and the proportion of TNF-a-positive lymphocytes.