patient aged 64 was admitted to the county hospital urology ward in september 2010 and diagnosed with tumor of the left kidney . ultrasonographic exam revealed the structure with a diameter of 45 mm in the central field of the left kidney . ct showed a solid focal lesion of the left kidney ( 30 x 40 x 32 mm ) located below the renal stalk and covering the renal pelvis and the paranephric section of the left ureter , apart from that no changes were observed ( figure 1 ) . radiological image of the chest did not reveal any pathological changes . in order to make the results of pre  operational diagnosis sided ureterorenoscopy was conducted and a urine sample was taken for cytology to exclude epithelial nature of the tumor . after undergoing the above  mentioned test , the patient was qualified for transperitoneal radical nephrectomy . with general anesthesia applied , the left kidney was removed through an incision below the left costal margin . during the operation , a significant peripheral infiltration was discovered which hindered access to the renal stalk of the left kidney . operative course passed without complications and the patient was discharged in good general condition 8 days after the surgery . left kidney tumor in ct exam . on pathological examination ( samples no 12399241239928 ) in all samples after detailed hematological work  up which did not show any other tumors , the patient was qualified for radiation treatment and currently remains under permanent oncological supervision . medical records and literature mention several cases of malignant kidney lymphoma [ 1 , 2 ] . some authors claim that this entity accounts for 3% of all solid renal tumors among adults . lymphomatous renal involvement can have three different causes : most commonly it appears along with the generalized disease and enlarged lymph nodes . renal involvement develops without any symptoms then.it may be related to organ transplantation and infection with epstein such cases are rare and difficult to diagnose which may lead to mistakes in treatment . such cases are rare and difficult to diagnose which may lead to mistakes in treatment . the case presented in the report illustrates diagnostic and therapeutic difficulties that a urologist might encounter during treatment of patients with possible renal tumor . results provided by clinical imaging of focal lesions are inconsistent . what must always be taken into account is an atypical tumorous process , autoimmunological disorders as well as inflammatory condition . in this particular case control appointments in the department of hematology have been scheduled to take place every four months and the prognosis for the patient has been described as good . they develop from lymphocytes and , depending on the variety of b and t lymphocytes , those processes can have different clinical outcome . some of them are located solely within the lymph nodes or tissues and internal organs , while others are accompanied by leukemia . it might seem that when it comes to lymphomas , the pathogens initiating the course of the disease could be both , the epstein  barr viruses which attack the b  lymphocytes , and by htlv1 viruses dwelling in t  lymphocytes and causing a subacute form of leukemia among adults . there can also be some co  factors of environmental character : chloro  organic compounds , ionization energy , benzene  like substances , states of immunosuppression and autoimmunological diseases . the malignant lymphoma morbidity rate can also be increased by extensive exposition to herbicides , and is even 35 times higher among patients with a kidney transplant . it usually dwells within the lymphoid tissue of waldeyer 's ring , spleen and thymus . extranodal lymphomas can most often be found in the gastrointestinal tract , other types can be located in skin , bones , eye kidney might be at the stage of involvement which spreads through lymphatic system from the nodes in retro peritoneum . if the renal involvement occurs at an advanced stage of the disease , as yet another location of it , it is relatively easy to diagnose . once a patient is diagnosed with lymphoma of kidney , further examinations are required in order to rule out a systemic disease . the necessary test in such cases include : blood tests , bone marrow biopsy , radiological examination , pathomorphological evaluation and histo  immunological evaluation of enlarged lymph nodes . the malignant types , however , build up rapidly , are resistant to treatment and show no signs of improvement within a short period of time . how long the patient will live depends on the histopathological diagnosis of the tumor and its stage of development . non  hodgkin lymphomas are treated with chemotherapy , radiation , and , in some cases , surgeries . low  malignant , originally extranodal , tumors are usually surgically removed and treated with radiotherapy . cell lymphoma associated with chronic inflammation arising in a renal pseudocyst with barely noticeable clinical symptoms . publications in english present several cases of spontaneous rupture of the ureter as primary symptom of malignant lymphoma . risk of their occurrence increases from 1.2% in 5 years after the operation , to 6.8% in 20 years after the transplantation , which is related to epstein barr virus infections . some authors also report on cases of co  existence of inflammatory intestines disease , including the crohn disease , and malignant lymphomas but then changes can most frequently be located in the vicinity of intestines or other adjacent sections of the digestive tract . the presented case leads to a conclusion that each focal lesion of unclear etiology found on imagining studies should be treated as a possible malignant lymphoma and ought to be histopathologically verified as quickly as possible .
we present a 64year  old patient suffering from extranodal malignant lymphoma . 
 the patient was admitted to the county hospital urology ward with suspicion of the left kidney tumor . as part of pre 
 operational diagnosis , ultrasonographic examination and computed tomography of kidneys were conducted . 
 the results confirmed the initial diagnosis . after undergoing radical surgical treatment , the patient is currently under the care of hematology ward of oncology centre .