Cystic nephroma overview

# Overview
Cystic nephroma is a type of rare benign kidney tumor. On gross pathology, large, unilateral, multiloculated, and well-encapsulated cystic tumor is the characteristic finding of cystic nephroma. On microscopic histopathological analysis, cysts lined by a simple epithelium with a hobnail morphology and ovarian-like stroma are characteristic findings of cystic nephroma. Cystic nephroma is caused by mutations in the DICER1 gene. Cystic nephroma must be differentiated from Wilm's tumor, renal cell carcinoma, cystic mesoblastic nephroma, and autosomal recessive polycystic kidney disease. 
Cystic nephroma is a rare disease that tends to affect paediatric population and individuals in the 5th - 6th decades. In paediatric population, males are more commonly affected with cystic nephroma than females. In later life, females are more commonly affected with cystic nephroma than males. Cystic nephromas are often asymptomatic. Possible symptoms of cystic nephroma include hematuria, urinary frequency, and dysuria. Biopsy is helpful in the diagnosis of cystic nephroma. Surgery is the mainstay of treatment for cystic nephroma. Common complications of cystic nephroma include infection, urinary tract obstruction, hemorrhage, and rupture. Prognosis is generally excellent.

# Classification
There is no classification system established for cystic nephroma.

# Pathophysiology
On gross pathology, large, unilateral, multiloculated, and well-encapsulated cystic tumor is the characteristic finding of cystic nephroma. On microscopic histopathological analysis, cysts lined by a simple epithelium with a hobnail morphology and ovarian-like stroma are characteristic findings of cystic nephroma.

# Causes
Cystic nephroma is caused by mutations in the DICER1 gene.

# Differential diagnosis
Cystic nephroma must be differentiated from Wilm's tumor, renal cell carcinoma, cystic mesoblastic nephroma, and autosomal recessive polycystic kidney disease.

# Epidemiology and Demographics
Cystic nephroma is a rare disease that tends to affect paediatric population and individuals in the 5th - 6th decades. In paediatric population, males are more commonly affected with cystic nephroma than females. In later life, females are more commonly affected with cystic nephroma than males.

# Risk Factors
There are no established risk factors for cystic nephroma.

# Screening
According to the the U.S. Preventive Service Task Force (USPSTF), there is insufficient evidence to recommend routine screening for cystic nephroma.

# Complications and Prognosis
Common complications of cystic nephroma include infection, urinary tract obstruction, hemorrhage, and rupture. Prognosis is generally excellent.

# Diagnosis

## Staging
There is no established system for the staging of cystic nephroma.

## History and Symptoms
Cystic nephromas are often asymptomatic. Possible symptoms of cystic nephroma include hematuria, urinary frequency, and dysuria.

## Physical Examination
Physical examination of patients with cystic nephroma is usually remarkable for a palpable abdominal mass.

## Laboratory Findings
There are no laboratory findings associated with cystic nephroma.

## X Ray
Abdominal X-ray may be helpful in the diagnosis of cystic nephroma. Findings on X-ray suggestive of cystic nephroma is a large abdominal mass displacing and effacing adjacent bowel loops.

## CT
CT scan may be helpful in the diagnosis of cystic nephroma. Findings on CT scan suggestive of cystic nephroma include large multilocular encapsulated cystic mass, herniation into the renal pelvis, variable septal enhancement, and associated streakiness in perirenal fat.

## MRI
MRI may be helpful in the diagnosis of cystic nephroma.

## Ultrasound
Ultrasound may be helpful in the diagnosis of cystic nephroma. Findings on ultrasound suggestive of cystic nephroma is a renal mass with multiple circumscribed sonolucent areas.

## Other Imaging Findings
There are no other imaging findings associated with cystic nephroma.

## Other Diagnostic Studies
There are no other diagnostic study findings associated with cystic nephroma.

## Biopsy
Biopsy is helpful in the diagnosis of cystic nephroma.

# Treatment

## Medical Therapy
The mainstay of therapy for cystic nephroma is surgery.

## Surgery
Surgery is the mainstay of treatment for cystic nephroma.

## Primary Prevention
There is no established method for prevention of cystic nephroma.

## Secondary Prevention
There are no secondary preventive measures available for cystic nephroma.