Primary duodenal lymphoma: successful rituximab treatment and evaluation by FDG-PET.

A 68-year-old woman has been suffering from chronic inactive hepatitis with hepatitis C virus. Upper endoscopic and pathological findings revealed the typical features of duodenal follicular lymphoma and Helicobacter pylori (H. pylori) infection with her stomach was confirmed by the histological and cultural examinations. No other abnormal findings suspicious for tumor formation were observed by the various examinations such as computed tomography, abdominal ultrasonography and 67Ga-citrate scintigraphy. Primary duodenal follicular lymphoma: stage I according to the Modified Ann Arbor classification was diagnosed by these procedures. The eradication therapy was effective for the withdrawal of H. pylori but not for lymphoma. Four months later, abdominal ultrasonography and magnetic resonance imaging showed the progression of abdominal lymph nodes. Positron emission tomography (PET) with 18F-fluorodeoxyglucose showed radioactive uptake in mesenteric lymph nodes. Systemic chemotherapy using rituximab was started, since these findings suggested the clinical progression from stage I to II2. After 2 courses of the therapy, endoscopic and histological improvement of duodenal lymphoma and lower uptake in mesenteric lymph nodes suggested us complete remission. Rituximab may be useful for duodenal follicular lymphoma and PET with 18F-fluorodeoxyglucose has a potential value for the evaluation of mesenteric lymph nodes spread.