Brief Answer: Need to monitor Detailed Answer: Hello Mr XXXXXXX Thank you for sending in your query. A renal cyst is a fluid filled cavity in the kidney. The exact reason why it forms is not known. From your description you appear to have a simple renal cyst. Simple renal cysts are observed frequently in normal kidneys. Their prevalence increases with age. As many as 20% of the individuals above the age of 60 may show a renal cyst. Majority of the simple renal cysts are asymptomatic. In very rare cases they may rupture and produce abdominal pain or bleeding from urine. Your cyst is 18 mm; it is too small to produce any signs or symptoms. There is no medical treatment available or required for your current problem. However what is required is periodic monitoring. We should repeat an ultrasound in a year or so to see the status of the cyst. I hope this was helpful. Feel free to contact me if you have more questions. Regards Dr. Aditya Bhabhe

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