Cyst is a sac filled with fluid. Renal Cyst is a kidney disease caused by solitary (single) or multiple cysts that is filled with fluid situated at the surface or within the kidney tissue. The renal cyst is a fluid filled pouches in the kidney that may or may not cause symptoms. Disease associated with multiple renal cysts is also known as cystic kidney disease or polycystic kidney disease. In this article, we will read in detail about the various causes, symptoms, risk factors, and treatment for Renal Cysts.
How Do We Define Renal Cyst?
- Kidney Cysts-
- Cyst often lies near the surface of the kidney. The shape of the cyst is round with regular or irregular circumference or border. Fluid filled within the cyst is serous fluid, looks clear or mild yellowish in color.
- Solitary Cyst-
- Solitary kidney cysts are simple cysts, which rarely causes any complication.
- Usually, there is only single small cyst, which lies on the surface of the kidney.
- Large and Multiple Cysts-
- Large or multiple kidney cysts may be associated with potentially serious medical conditions, which may affect the function of the kidneys.
- The large cyst may cause end stage renal disease.
- Multiple Renal Cyst may be observed in both kidneys.
- Origin of Cyst-
- It is not clear as to how exactly Renal Cysts originate.
- Asymptomatic Solitary Renal Cysts-
- Single asymptomatic renal cyst is diagnosed during image study.
- Image study is often done for diagnosis of abdominal pain or abdominal diseases.
- Solitary asymptomatic renal cyst is not aggressively treated.
Causes of Renal Cysts
As stated above, Renal Cysts do not have a clear cut cause. One assumption is that Renal Cysts develop when the top layer of the kidney becomes weak resulting in formation of a pouch which then gets filled with fluid resulting in the formation of a Renal Cyst.
Risk Factors For Renal Cysts
Renal Cyst Risk Factors Are As Follows-
- Age- Elderly patients
- Blunt trauma
Symptoms Of Renal Cysts
Non-Infected Renal (Kidney) Cyst
- Pain
- Flank- dull to severe pain over the flank, may radiate to lower back.
- Abdomen- Pain is localized over upper abdomen either right or left side depending on side of kidney with renal cyst.
Infected Renal (Kidney) Cyst-1
- Fever With Chills
- Infected cyst may present with fever of unknown origin. Fever is often associated with chills. Fever often does not respond to anti fever medications like Tylenol.
- Pain
- Flank– Pain is often moderate to severe in intensity. Examination of flank is often associated with tenderness and increased pain on examination and palpation.
- Abdomen– Pain is localized over upper abdomen either right or left side depending on side of kidney with renal cyst. Pain is increased following examination.
Renal Cyst: End Stage Renal Disease (Very Rare)
- Low urine output
- Weakness and fatigue
- Loss of weight
- Nausea and vomiting
- Dry skin and itching
- Confusion and change in mental status
Diagnosis of Renal Cysts
Diagnosis of Non Infected Renal Cyst
- Ultrasound
- CT Scan
- MRI
Diagnosis of Infected Renal Cyst
- Blood Examination
- Complete Blood Count
- Increased white blood cell count
- Increased Erythrocyte Sedimentation Rate.
- Complete Blood Count
- Ultrasound
- CT Scan
- MRI
End Stage Renal Disease
- Urine Examination
- Proteinuria
- Low Urine Output
- Hematuria
- Blood Examination
- Elevated Blood Urea Nitrogen
- Elevated Serum Creatinine
- Image Studies
- Ultrasound
- CT Scan
- MRI
Treatment For Renal Cysts
Treatment For Non Infected Renal Cyst
- Solitary or Multiple Asymptomatic Renal Cyst-
- No Treatment
- Periodic Image study to observe the growth of the cyst
- Solitary (Single) or Multiple Symptomatic Cyst
- Pain Medications-
- NSAIDS– Motrin, Tylenol or Celebrex
- Percutaneous Drainage of the Tube-
- Drainage of the Cyst: This is done by draining the fluid filled in the cyst and then filling it with alcohol to prevent it from recurring but in most cases the cyst formation recurs even after the procedure and hence this sort of procedure is reserved only for certain situations.
- Percutaneous CT Guided Sclerotherapy of Cyst-2
- Needle is inserted under CT guidance. Once needle is placed within the cyst, dye is injected to confirm the position of the needle.
- Following the dye study, ethanol is injected in the cyst. Ethanol causes inflammation and scarring, which closes the cystic space.
- Surgical Exploration and Removal of Cyst
- Surgery For Removal of Renal Cyst: An enlarged Renal Cyst or a cyst that becomes symptomatic can be treated by surgical removal of the cyst.
- Pain Medications-
Infected Solitary or Multiple Renal Cyst
- Antibiotics
- Pain Medications
- Surgical Treatments-
- Percutaneous drainage of the tube
- Surgical exploration and removal of cyst
- Endoscopic deroofing of the cyst.3
Complications Of Renal Cysts
Renal Cyst Complications Include-
- Infection of the Cyst: In this case, the individual may experience pain and fever.
- Rupture of the Cyst: In this case, there may be excruciating pain in the back or the sides.
- Obstruction of Urine Flow: In this case, there may be formation of a medical condition called hydronephrosis.
References:
1. Infection of a renal cyst, a rare complication of bronchopneumonia
Manenti A1, Boticelli A, Gibertini G, Zanni G.,
Acta Urol Belg. 1990;58(3):145-9.
2. CT-guided sclerotherapy for simple renal cysts: value of ethanol concentration monitoring.
Yu JH1, Du Y2, Li Y2, Yang HF2, Xu XX2, Zheng HJ2.
Korean J Radiol. 2014 Jan-Feb;15(1):80-6. doi: 10.3348/kjr.2014.15.1.80. Epub 2014 Jan 8.
3. Retroperitoneoscopic deroofing of a giant renal cyst in a solitary functioning hydronephrotic kidney with a 3-port technique.
Singh I1, Sharma D, Singh N.
Surg Laparosc Endosc Percutan Tech. 2003 Dec;13(6):404-8.
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