[Sustained remission over 10 years after rituximab-monotherapy in a patient with primary duodenal follicular lymphoma].

A 79-year-old man received gastrointestinal endoscopy for reexamination of a gastric submucosal tumor in May 2002 and whitish granular mucosa was found near the ampulla of Vater of the duodenum, though biopsy specimens showed only lymphocyte infiltrations. In December 2002, a second gastrointestinal endoscopy revealed an irregular granular elevated lesion around the ampulla of Vater and biopsy specimens showed pathological findings of follicular lymphoma. No other abnormal findings raising suspicion of tumor formation were observed on systemic examinations and the diagnosis of duodenal follicular lymphoma was confirmed. Systemic chemotherapy using rituximab at 375 mg/m(2) weekly for 4 consecutive weeks was started in January 2003. Six months later, endoscopic findings of the lesions revealed nearly normal mucosa around the ampulla of Vater, though histologically the biopsy specimens showed residual lymphoma cells. The same rituximab therapy as before was started in November. There has been no evidence of recurrence and a prolonged, more than 10 years, complete remission has been achieved.