[Clinicopathological Observation of Primary Renal Non-Hodgkin's Lymphoma--A Report of Two Cases].

Objective: To investigate the clinicopathological and immunohistochemical features as well as diagnosis, differential diagnosis,treatment and prognosis of patients with primary renal non-hodgkin's lymphoma (PRNHL).

Methods: Clinical data of 2 patients with PRNHL from January 2013 to October 2017 were retrospectively analyzed.

Results: One of the two male patients PRNHL aged 51 years old, admitted to hospital for swelling and pain in the right waist, B-ultra sonic examination showed a very solid upper right renal space occupying lesion. CT showed the soft tissue mass of the right kidney about 10.5 cmx 8.6 cm. Preoperative diagnosis was a right kidney cancer subjected to radical surgery, and the postoperative pathological diagnosis was a right renal diffuse large B cell lymphoma (DLBCL). Expression of CD20, CD79a, Mum-1, BCL-2, BCL-6 in tumor cells was identified by inmmunohistochemistry, and Ki-67 proliferation index was 90%. Six courses of chemotherapy with R-CHOPE regimen were carried out supplemented local radiotherapy. The patients were followed up for 32 months, which were generally in good condition and stable. The another patient was 65 years old, no without obvious clinical symptoms, B-ultrasonic examination found a space occupying lesion in the left kidney. Abdomind CT scan plus enhancement showed the left kidneydisplayed uneven enhanced lesions of size 9 cm x 5 cm, the preoperative diagnosis was left kidney cancer, the pathological diagnosis was diagnosed as mall B cell lymphoma of the left kidney after the radical operation. Immunohistochemistry determined expression of CD20, CD79a, pax-5, BCL-2 in tumor cells and Ki-67 proliferation index 10%. 6 courses of chemotherapy with CHOPE regimen had been performed and followed up for 20 months, the conditions were generally good and stable.

Conclusion: PRNHL is a rare extranodal non-Hodgkin lymphoma with atypical clinical symptoms characterized by lumbar swelling pain. It is easy to be misdiagnosed as renal cell carcinoma before operation. The diagnosis depends on pathology and immunohisto-chemistry. The prognosis of 2 patients was relatively good. PRNHL should be differetiated with renal sarcomatoid cancer, nephroblastoma and other diseases. Surgical resection plus chemotherapy is recommended.