I had a ct scan and informed i have a 6mm "low density" lesion that the radiologist is calling a cyst. i am 35 years old and freaking out. i had 2 ct and 1 ultrasound. ultrasound saw nothing. are lesions in kidney common? are kidney cysts common?

There may be an association between renal cysts and pulmonary cysts. The negative renal ultrasound is reassuring but should be interpreted in the context of symptoms. The reason for the Chest CT and any pulmonary symptoms is not presented. Do you smoke? Have you been exposed to Histoplasmosis or TB- recommend screening for both. A risk assessment may include a family history, size, location.

At your age, one simple renal cyst of 0.6 cm is relatively common and renal ultrasound may miss this tiny cyst. You should not lose your sleep with this finding.