Abstract: Primary Renal Lymphoma:A Report of 7 Cases and Literature ReviewWeiwei YU, HuaqingWANG, Xianming LIU, Zhengzi QIAN, Huilai ZHANG, Lihua QIU, Xishan HAOCorrespondence to: HuaqingWANG, E-mail: huaqingw@163.comDepartment of Lymphoma, Tianjin Medical University Cancer Institute and Hospital, Sino-US Center for Lymphoma and Leukemia,Tianjin Key Laboratory of Cancer Prevention and Therapy, Tianjin 300060, ChinaAbstract Objective: To explore the incidence rate, clinical characteristics, metastasis, treatment and prognosis of primary renallymphoma ( PRL ). Methods: Clinical data of 7 patients with PRL treated between January 2000 and January 2009 were retrospectivelyanalyzed with complete follow-up data. The clinical data included sex, age, symptoms, signs, pathological type, renal B ultrasound, CTand PET-CT imaging. Results: The incidence rate of PRL in Tianjin city was 6.58 per 10 million between January 2000 and January2009. Of the 7 patients in this study, there were 3 males and 4 females. The age at the onset of the disease ranged from 10 to 72 years,with an average of 55.5. Patients presented with unilateral renal masses. Four patients complained of lumbodynia or hematuria; two pa-tients had incidentally detected renal masses during routine physical examinations; one patient complained of fever and night sweats.All patients underwent nephrectomy and three patients underwent renal biopsy. All cases were identified as non-Hodgkin lymphomathrough histopathological examination with 6 tumors originating from B-cells and one originating from T-cells. All patients receivedCHOP or CHOP-like chemotherapy. The mean survival time for males and females was 9 and 19.5 months, respectively; the mean sur-vival time on the International prognostic index ( IPI ) ( 0, 1, 2 ) was 30.5, 10.5 and 7.7 months, respectively; the mean survival time forchemotherapy and nephrectomy combined with chemotherapy groups was 8.7 and 19.8 months, respectively. Conclusion: PRL is a rareextranodal lymphoma. It is easily misdiagnosed due to its nonspecific clinical manifestations and imaging features. The diagnosis ofPRL is confirmed through histopathological examination. Nephrectomy combined with chemotherapy can improve the prognosis. How-ever, the prognosis is still rather poor. It is most likely associated with gender, tumor size, IPI, and mode of treatment.Keywords Primary renal lymphoma; Incidence rate; Clinical characteristics; Treatment; Prognosis