AIM:To investigate the feasibility of double-balloon endoscopy(DBE) to detect jejunoileal lymphoma,compared with fluorodeoxyglucose positron emission tomography(FDG-PET).METHODS:Between March 2004 and January 2011,we histologically confirmed involvement of malignant lymphoma of the jejunoileum in 31 patients by DBE and biopsy.In 20 patients of them,we performed with FDGPET.We retrospectively reviewed the records of these 20 patients.Their median age was 64 years(range 50-81).In the 20 patients,the pathological diagnosis of underlying non-Hodgkin’s lymphoma(NHL) comprised follicular lymphoma(FL,n = 12),diffuse large B cell lymphoma(DLBCL,n = 4),mantle cell lymphoma(MCL,n = 2),enteropathy associated T cell lymphoma(ETL,n = 1) and anaplastic large cell lymphoma(ALCL,n = 1).RESULTS:Ten cases showed accumulation by FDGPET(50%).FDG-PET was positive in 3 of 12 FL cases(25%) while in 7 of 8 non-FL cases(88%,P < 0.05).Intestinal FL showed a significantly lower rate of positive FDG-PET,in comparison with other types of lymphoma.Cases with endoscopically elevated lesions(n = 10) showed positive FDG-PET in 2(20%),but those with other type NHL did in 8 of 10(80%,P < 0.05).When the cases having elevated type was compared with those not having elevated type lesion,the number of cases that showed accumulation of FDG was significantly smaller in the former than in the latter.CONCLUSION:In a significant proportion,small intestinal involvement cannot be pointed out by FDG-PET.Especially,FL is difficult to evaluate by FDG-PET but essentially requires DBE. To investigate the feasibility of double-balloon endoscopy (DBE) to detect jejunoileal lymphoma, compared with fluorodeoxyglucose positron emission tomography (FDG-PET). METHODS: Between March 2004 and January 2011, we histologically confirmed involvement of the malignant lymphoma of the jejunoileum in 31 patients by DBE and biopsy. In 20 patients of them, we performed with FDG PET. We retrospectively reviewed the records of these 20 patients. The median length was 64 years (range 50-81). In the 20 patients, the pathological diagnosis of underlying non-Hodgkin’s lymphoma (NHL) follicular lymphoma (FL, n = 12), diffuse large B cell lymphoma (DLBCL, n = 4), mantle cell lymphoma ETL, n = 1) and anaplastic large cell lymphoma (ALCL, n = 1) .RESULTS: Ten cases showed accumulation by FDG PET (50%). FDG-PET was positive in 3 of 12 FL cases (25%) while in 7 of 8 non-FL cases (88%, P <0.05) .Intestinal FL showed a significantly lower rate of positive FDG-PET, in compar ison with other types of lymphoma. Cases with endoscopically elevated lesions (n ​​= 10) showed positive FDG-PET in 2 (20%), but those with other type NHL did in 8 of 10 the cases having elevated type was compared with those not having elevated type lesion, the number of cases that showed accumulation of FDG was significantly smaller in the former than in the latter. CONCLUSION: In a significant proportion, small intestinal involvement can not be pointed out by FDG-PET.Especially, FL is difficult to evaluate by FDG-PET but essentially requires DBE.