multicystic dysplastic kidney ( mcdk ) is a congenital anomaly that is the result of abnormal interaction between the ureteric bud and metanephric mesenchyme , early ureteral obstruction , or ureteral atresia . mcdk is usually presented as the formation consisted of multiple cysts of varying sizes , without normal renal parenchyma . the significant number of mcdks involute and disappear during the fetal period and the early childhood . a relatively rare associated anomaly is the presence of ipsilateral refluxing blind megaureter , which is the result of abnormal development of the vesicoureteral junction ; it is usually presented as elongated tubular pseudo - intestinal cystic structure . refluxing blind megaureter a 23year  old woman from a small village was sent to the urologist from the gynecologist , due to solitary right kidney , cystic mass on the left side of the urinary bladder and the presence of chronic pain and urinary infection . girl 's mother stated that fetal ultrasonography ( usg ) in 9 gestational month revealed a cystic left kidney . at the age of two , abdominal usg revealed 22 mm large cystic formation in the position of the left kidney . intravenous urography ( ivu ) and renal scintigraphy revealed normal right kidney and the absence of the left kidney . during the next years , the girl was admitted several times to regional hospital , due to recurrent urinary infections and febrile episodes . at the age of 14 , cystography revealed vesicoureteral reflux ( vur ) grade ii on the right side and vur grade i in the blind megaureter . after that , there were no more urinary infections and vur spontaneously disappeared on the both sides . the young lady refrained from medical controls until she was married . at the age of 23 , she visited gynecologist , due to chronic pelvic pain and inability to stay pregnant . the gynecological examination revealed bizarre cystic mass in the pelvis , caudal and left to the urinary bladder . a computerized tomography ( ct ) scan revealed the presence of the 15-cm - long pseudo - cystic mass in the pelvis . the left kidney was absent while the right kidney was hypertrophic ( figure 1 ) . ct showing pseudocystic formation on the left and beneath the urinary bladder . at the admission on urology , cystoscopy revealed clear urine , normal bladder capacity , symmetric trigone , normal right orifice , while the left orifice could not be identified . transvaginal ultrasonography revealed the presence of 15 cm long gut - like pseudocystic formation on the left side and beneath the urinary bladder . the patient underwent ureterectomy of the blind megaureter , through the left oblique pelvic incision . the ureter was 24 cm long and 4 cm wide , with the 5 - 7 mm thick wall . pathological diagnosis revealed megaureter and fibroproductive chronic ureteritis ( figure 2 ) . removed blind - ended megaureter . unfortunately , one year after the surgery , she developed hyperthyreosis , complicated with exophthalmos . at the last visit , the explanation of the association of mcdk and the primary megaureter ( pm ) is that both anomalies are the consequence of the abnormal development of the ureter ; both anomalies are more often on the left side and boys are more commonly affected . generally , pm is the result of abnormal development of the vesicoureteral junction ; distal ureteral segment can be aperistaltic and fibrotic ( obstructed pm ) , or short , with decreased amount of smooth muscle ( refluxing pm ) . in 10 - 15% of cases of pm , contralateral kidney is absent or dysplastic . in about 60% of the cases of the unilateral mcdk , the ipsilateral ureter is completely absent . the most commonly associated anomaly is contralateral vur , in almost 20% , while the incidence of ipsilateral vur is relatively low , about 4% [ 4 , 5 ] . mcdk can be associated with the malformations of the vagina , uterine horn , fallopian tube or ovary in female , or with the absence of the ipsilateral testis , vas deferens , or seminiferous tubules in male [ 6 , 7 ] . in 93 patients with mcdk , merrot found six cases with vanishing mcdk and cystic masses close to the urinary bladder . in addition , he found that 15% of patients had malformations of the ipsilateral genitalia . in a child with involuted mcdk , vur into the blind megaureter may cause abdominal or pelvic pain and chronic urinary infection . abdominal ultrasonography ( us ) usually shows multiple cysts without renal parenchyma , or the absence of the kidney . computerized tomography urography ( ctu ) or magnetic resonance urography ( mru ) , are sometimes necessary to confirm the diagnosis and to estimate the status of ipsilateral kidney . the treatment of mdck is usually conservative , as the majority of mcdks spontaneously disappear during childhood . however , these conditions sometimes require conservative treatment , due to urinary infection ; nephrectomy is indicated very rarely . the treatment of pm is indicated in the cases of renal involvement , chronic urinary infection and calculosis , while in adult age pm is usually asymptomatic and requires only conservative treatment [ 9 , 10 ] . in the presented case , left mcdk was discovered prenatally and the ipsilateral blind refluxing pm , at the age of two . the girl was followed - up due to recurrent urinary infections , but later , she was asymptomatic and no medical controls . the last cystography failed to detect vur in the right ureter and the left blind ureter as well . it is interesting that with time , massive blind megaureter become completely occluded at the level of orifice . we can speculate that vur in the megaureter existed for a long time , which caused its marked dilatation and tortuosity . it is likely that chronic urinary infection and fibrosis lead to gradual narrowing of the refluxing orifice and , at last , to its closure . later on , large pseudocystic formation became the cause of chronic abdominal and pelvic pain and the chronic urinary infection . the patients with involuted mcdk and ipsilateral blind megaureter should have long term follow - up due to possible complications . complete resection of blind megaureter should be performed in cases of chronic urinary infection and chronic abdominal or pelvic pain .
multicystic dysplastic kidney ( mcdk ) is a congenital anomaly as the result of abnormal interaction between the ureteric bud and metanephric mesenchyme . 
 unilateral mcdk can be associated with other anomalies of the genitourinary tract . relatively rare 
 associated anomaly is the presence of ipsilateral refluxing blind megaureter.the patient reported herein is a 23years  old woman with involuted mcdk and ipsilateral blind megaureter causing chronic urinary infection and chronic abdominal pain . 
 preoperative and intraoperative examination failed to detect the communication between megaureter and the urinary bladder .