Mesalazine-Induced Temporary Remission of Colonic Ulcers in Primary Intestinal NK/T-Cell Lymphoma: A Case Report and Literature Review

Abstract Purpose We present a rare case of short-term healing of colonic ulcers caused by Primary Intestinal NK/T-cell Lymphoma following mesalazine treatment. Methods Clinical, endoscopic, and pathological data from a patient treated at the Second Hospital of Lanzhou University were retrospectively analyzed. Literature on mesalazine was reviewed to explore potential mechanisms underlying ulcer healing in Primary Intestinal NK/T-cell Lymphoma. Clinical trial number: not applicable. Results A 21-year-old female presented with recurrent fever and colonic ulcers, pathologically confirmed as Primary Intestinal NK/T-cell Lymphoma. After six months of oral mesalazine (4 g/day), colonoscopy revealed ulcer healing, accompanied by resolution of abdominal pain and fever. The patient’s family declined further chemotherapy. Unfortunately, 1 year later, she was hospitalized for colonic perforation, underwent emergency surgery, and received postoperative chemotherapy.The patient died 2 years after the surgery. Conclusion This case suggests that mesalazine may induce transient mucosal healing in Primary Intestinal NK/T-cell Lymphoma-associated ulcers, potentially masking disease progression. Clinicians should remain vigilant and conduct long-term follow-up even if mesalazine treatment is effective for colonic ulcers.