Renal cysts represent notably dilated nephrons or collecting ducts. A cystic kidney is a kidney with three or more cysts. The accuracy of CT diagnosis of typical simple renal cyst approaches 100% but many renal cysts do not fulfill the criteria for simple renal cyst, such lesions vary from simple renal cysts which do not require surgery to renal neoplasms with cystic component that need surgical resection. Contrast-enhanced helical CT scanning has 96% sensitivity and 95% specificity in detecting carcinoma in acquired renal cystic diseases.
AIM OF STUDY:
To confirm the sensitivity, specificity and performance of the spiral computed tomography (CT) in diagnosis and evaluation of the renal cysts and to study the CT criteria which categorize and separate the renal cystic lesions that require surgery (malignant neoplasm) from those that do not.
Fifty patients were scanned with spiral CT, 22 of them were males and 28 were females, their ages ranging from 20-70 years with mean age 50 yeas old, these patients undergo CT examinations with and without contrast enhancing material. All the patients were proved to have renal cysts radiologically and symptomatically.
The patients presented with cortical simple renal cysts were 16 patients (32% of all the cases). Medullary simple renal cyst were found in 9 patients (18% of the total number of cases). 3 patients presented with autosomal recessive and dominant poly cystic kidney disease (8% of total cases). 1 case found with cystic kidney associated with tuberous sclerosis (2% of total cases). Para-pelvic renal cysts are seen in 7 patients (14% of total cases). Cystic angiomyolipoma (fat density) are seen in 3 patients (6% of total cases). Acquired renal cystic disease is found in 1 patient (2% of total cases). Complicated renal cysts (hemorrhagic) are seen in 2 patients (4% of total cases). Medullary cystic diseases were found in 2 patients ( 4% of total cases). Multicystic dysplastic kidney was found in 1 patient (2% of total cases). Malignant Cystic kidney lesion (cystic renal cell carcinoma) was found in 1 patient (2% of total cases). Females are more affected than the male, 28 females (56%) while the affected males were 22 (44%). The more involved age group was between 50-59 years old, they were 15 patients (9males and 6 females). The left kidney (34%) is more involved than the right kidney (32%), while both kidneys were involved in (34%) of the cases.
The spiral CT scan is the most sensitive imaging modality useful in diagnosis of cystic kidney and it is of valuable importance in evaluation and categorization of cystic renal masses in attempt to separate the lesions that require surgical resection from those do not