Cysts are abnormal, closed, sac-like structures that are filled with a solid, fluid, or semifluid material. In cystic diseases of the kidney, the size of the organ is increased, but the amount of functional renal tissue is decreased.

Many cystic conditions are inherited disorders or occur secondary to infection. Major cystic diseases of the kidney include polycystic kidney disease, medullary cystic disease, and medullary sponge disease.

Manifestations of the major groups of cystic diseases of the kidneys are as follows:

• Polycystic kidney disease - The condition is a very slow, progressive disease with onset seen in early or mid-adult life. The cysts produce the symptoms of back pain, blood in the urine, infection of the urinary system, kidney stones, or uremic symptoms from loss of kidney function. Asymptomatic cysts may be present in the liver. Over 50% of patients have hypertension, and about 10% of the older population have intracranial aneurysms (abnormal dilation of an arterial wall). Mitral valve prolapse of the heart occurs in a third of the patients, and antimicrobial therapy as well as a valve replacement may be required.

• Medullary cystic disease - Between the ages of 20 and 50 years of age, end-stage renal disease appears. The first symptom is polyuria (excessive secretion of urine), and loss of sodium is severe enough to require replacement. Finally, uremic symptoms appear.

• Medullary sponge kidney - The condition is often asymptomatic until renal colic (pain) from stones, hematuria (blood in urine) and urinary tract infection (UTI) appear.

Diagnostic measures for the major groups of cystic diseases of the kidneys are as follows:

• Polycystic kidney disease - The kidneys become very large and palpable. Pus, blood, and protein are found on urinalysis, and the urine is grossly bloody when a cyst ruptures. Ultrasound and computed tomography (CT) scan show irregular outlines and a moth-eaten appearance due to cysts.

• Medullary cystic disease - The serum chemistry signifies chronic renal failure. Since cysts may be small, a special thin-section CT scan may be needed for visualization.

• Medullary sponge kidney - Radiography of the urinary tract (urography) is used to differentiate this condition from others. The kidney pyramid cavities are shown to be filled with contrast material resembling a bunch of carnation flowers.

Treatment measures for the major groups of cystic diseases of the kidneys are as follows:

• Polycystic kidney disease - Eventually a kidney transplant or dialysis is needed to preserve life. Medical management of secondary high blood pressure and UTIs will prolong life significantly.

• Medullary cystic disease - With progression of the disease, treatment for chronic renal failure becomes necessary. There is a high success rate for transplantation.

• Medullary sponge kidney - Antimicrobial therapy for UTIs and recurrent stones is necessary. There is no specific treatment for stone formation, but a high-fluid intake may deter stone formation or obstruction or both.

Hereditary diseases require genetic counseling. Transplantation from family members is not practical. Total renal failure will require lifelong dialysis or renal transplant, which would require taking transplant-rejection medications for life.

• This disease, (condition), only in its active form , has a 3 year presumptive period and shall be granted service connection although not otherwise established as incurred in or aggravated by service if manifested to a compensable degree within the applicable time limits under 38 CFR 3.307 following service in a period of war or following peacetime service on or after January 1, 1947, provided the rebuttable presumption provisions of 38 CFR 3.307 are also satisfied. [38 CFR 3.309 [Disease subject to presumptive service connection], 38 CFR 3.309(a). [chronic disease].

• May be entitled to special monthly compensation where the Veteran has a single service-connected disability rated as 100% with additional service-connected disability or disabilities independently ratable at 60% or more, which are separate and distinct from the 100% service-connected disability and involves different anatomical segments or bodily systems. See  38 CFR 3.350(i)(1) – Special Monthly Compensation (SMC).

• The new criteria for the Genitourinary Disease and Conditions body system became effective November 14, 2021.  Review both current and historic criteria prior to any reduction for disabilities established before that date.  38 CFR 3.951(a)

• When evaluating any claim involving loss or loss of use of one or more creative organs, refer to 38 CFR 3.350 of this chapter to determine whether the Veteran may be entitled to special monthly compensation. Footnotes in the schedule indicate conditions which potentially establish entitlement to special monthly compensation; however, there are other conditions in this section which under certain circumstances also establish entitlement to special monthly compensation.

• Cystic diseases of the kidneys include, but are not limited to, polycystic disease, uremic medullary cystic disease, medullary sponge kidney, and similar conditions such as Alport's syndrome, cystinosis, primary oxalosis, and Fabry's disease.

• GFR, estimated GFR (eGFR), and creatinine-based approximations of GFR will be accepted for evaluation purposes when determined to be appropriate and calculated by a medical professional.