Any anomaly concerning the kidney and the urinary system is termed as a renal concern. The Renal cyst is one such condition. Small fluid-filled pockets (which are better known as cysts) located inside the kidneys, which cause the kidneys to enlarge, are known as renal cysts. Sometimes, these cysts also contain a yellowish fluid mixed with blood. If the cyst is complex in nature, with solid material contained inside, it may be an indication to development of kidney cancer. These cysts, depending on the complication, lead to cystic disease. However, this disorder has a spectrum of reasons to occur, pertaining to the hereditary, developmental, or acquired conditions. In cases where there are many cysts (malign) in the kidneys, the condition is often termed as polycystic kidney disease.
Acquired Renal Cystic Disease (ARCD)
Also known as acquired cystic kidney disease, (ACKD) is a polycystic and bilateral condition, where there are many fluid-filled cysts in the kidneys. This condition has been diagnosed most, in people with absolutely no history of cystic diseases. In the early stages, when this condition has just set in, there are not any noticeable symptoms, until the abdominal pain starts showing up. In many patients, this condition has been discovered in abdominal imaging procedures.
Acquired cysts are round and are defined by sharp boundaries. They could be single or multiple. An Isolated cyst is not detectable in the initial stage unless, it has been discovered accidentally in some medical examination. Multiple cysts can also occur, and their cause is believed to be due to hyperplasia of residually functioning nephrons. Many a time, these cysts are asymptomatic except in certain cases, where patients may develop hematuria or renal hemorrhage. Other complications that may rise in this condition, are renal cell carcinoma (kidney cancer, being the major complication, which causes severe kidney pain) and precursor lesions in the epithelial proliferation in complex kidney cysts.
As per medical science, this disease is also closely associated with hemodialysis done for people, who have been suffering from kidney failure for a prolonged period. Hemodialysis is a medical procedure, in which, the blood is removed and then filtered to get rid of the waste products before being transfused back into the body. Many patients who undergo hemodialysis have higher chances of developing ARCD. In the general population, this disease is more common in men than in women.
Unilateral Renal Cystic Disease (URCD)
It is not a common condition and should not be confused with autosomal dominant polycystic kidney disease (ADPKD). This is because, the segmental cystic abnormality in the kidney is quite similar to autosomal dominant adult form of polycystic kidney disease. ADPKD is a genetic disorder of renal cyst formation in both kidneys, eventually leading to renal failure. Although, URCD is a multicystic disease, characterized by a number of cysts scattered over inside the kidney, its cause is not yet known. Neither is it hereditary nor does it lead to progressive deterioration in renal function.
Distinguishing this disease from ADPKD can be done by checking with the degree of confinement of the cystic disease. Cyst formation in one kidney, with an absence of the cysts in other organs (like pancreas and liver), and the absence intervening normal renal parenchyma between cysts can distinguish well between URCD and ADPKD.
The treatment of this disease starts with a diagnosis, wherein, a CT or an MRI scan is done to determine whether the cyst is malign or benign. Then the cysts are punctured and drained out to prevent further cyst formation. The above two diseases do not have any tangible causes, but can be a reverberation of certain forms of kidney cancer and other disorders.