a case of malign hemorrhagic renal cyst in a 32  year  old woman is reported . the patient was admitted to our hospital for further evaluation of right upper abdominal mass . the characteristic findings were thick and irregular wall and heterogeneous contents of the cystic mass . the presence of a malignant tumor in the cyst wall was suspected and nephrectomy was performed . the specimen measured 10 x 6 x 4 cm . renal cysts , in general , may be classified as  simple  or  complex  . the difficulty arises when cysts do not meet the rigid characteristics of the  simple  definition . therefore , clinicians need to rely on a rapid , safe and accurate system to identify benign versus malignant masses and ultimately have the guidance on nonsurgical or surgical treatment options . are prescribed as 0.5 - 1% of all renal cysts ( 1 , 2 ) . their clinical symptoms are not specific and are mainly similar to the symptomatology of tumors and simple renal cysts ( 3 , 8) . ivu , ultrasonic sonography , computed tomography - ct , magnetic resonance imaging - mri , diagnostic punction of cysts and renal arteriography can rare determine the diagnosis ( 4 , 5 ) . the diagnosis based on bosniak classification : bosniak 1 , bosniak 2 , bosniak 2f , bosniak 3 and bosniak 4 . therefore the diagnosis is mostly determined by surgical intervention ( 6 , 7 ) . in this study , the authors have presented their case of hemorrhagic malignant renal cyst , which is treated by surgical intervention  nephrectomy . we are going to present the case of a female patient referred to our clinic with the initial ultrasound diagnosis of right giant renal cyst about 10 cm . given the result of the ultrasound ( thick walls and small irregularities ) and the possibility of a complicated cyst , we decided to investigate the matter further , and programmed the patient for an enhanced abdominal computer tomography with intravenous contrast . the enhanced ct images revealed a right kidney cystic mass , with a 10 cm diameter , thick irregular walls with contrast enhancement , hyperdense content , and no pathological lymph nodes or distant metastases . the albanian urological association guidelines committee has reviewed the literature using a medline search of the english language . patient : xh.b , female 32 years old . symptoms : pain and feeling heaviness below right rib arch and right flank , for a long time intermittently and now more frequently . no hematuria noted elevated blood pressure laboratory assessment : esr : 10 ; glucose : 4.32 ; urea : 6.30 ; creatinine : 63.2 ; hgb : 127 ; rbc : 3.73 ; wbc : 7.6l ; hct : 0.36 . there is a large well defined formation that occupies about upper two  thirds of the right kidney . ( a.b ) : ct of the right kidney ; radiologist`s comment : very large renal mass lesion that occupies about upper two  thirds of right kidney . echotomografic findings : there is a large well defined formation that occupies about upper two -three of the right kidney sized 10 x 6 x 4 cm hypoechogenic with hyperechogenic walls . diagnosis is mainly based on histopathological features such as a well - developed capsule , fibrous stromata , multiple epithelial lining septa . according to bosniak the cyst is filled with fluid and can cause local tissue destruction as it enlarged . although the exact cause is unknown , cysts are considered structural defect that occurs prenatally . diagnosis of a simple renal cyst involves intravenous urography , echosonogarphy , diagnostic puncture , ct , mri . echosonogarphy is the most commonly applied method because it reveals some features of cysts of suggesting malignancy : irregular walls , internal echoes inside the walls and the cysts , lack of characteristic potentiation of ultrasound beam ( f).this indicate diagnostic punction and analysis cyst contents . if the aspirate is bloody there is ( tomas 2010 ) a 28 - 50 % chance of malignancy . a , 3b and 3c . surgical finding : there is an a large cystic formation that incorporate upper pole and middle area of the right kidney with thick and calcified capsule filled with hemorrhagic fluid and masse of loose costs . minimally complex : a few thin < 1 mm septa or thin calcifications ( thickness not measurable ) ; non - enhancing high - attenuation ( due to proteinaceous or hemorrhagic contents ) renal lesions of less than 3 cm are also included in this category ; these lesions are generally well marginated . minimally complex : increased number of septal , minimally thickened with nodular or thick calcifications . hyperdense cyst > 3 cm diameter , mostly intrarenal ( less than 25% of wall visible ) ; no enhancement . requiring follow - up : needs ultrasound . ct of follow up - no strict rules on the time frame but reasonable at 6 months . indeterminate : thick , nodular multiple septa or wall with measurable enhancement , hyperdense on ct ( see 2f ) . treatment / work - up : partial nephrectomy or radio - frequency ablation in elderly or poor surgical candidates . identifications of malignant cells established the definite diagnosis , while hemorrhagic contents , high lipid contention and lactate dehydrogenase - ldh are suggestive of malignancy . after pathological confirmation for malignant kidney cyst and adequate treatment , on these patients is likely to achieve long - term survival . the characteristic findings were thick and irregular wall and heterogeneous contents of the cystic mass . pathohistological examination showed evidence of malignant hemorrhagic renal cyst . which is treated by surgical intervention and usually nephrotomy .