I am 35 & was told on a ct scan that i have a retroperitoneal 13mm lymph node & 6mm "low density" lesion they think is a cyst. i had 2 ct scan 5 months apart & the node remained the same. i am scared. how serious is this? help!?

If the lesion has not gotten bigger in 5 months it is more than likely benign. You may choose to watch and wait. If you get bigger nodes in the neck, axilla, or groin, lose weight, get fever, see a doctor.

You are safe with these facts: retroperitoneal lymph node size can be in the range 0.7 -1.5 cm and the unchanged finding after 5 months rules out serious conditions. A 6 mm low density in the kidney (likely a cyst) is not uncommon at all at 35 years old and you are also reassured because this low density lesion, which should be read as a simple cyst, has not changed after 5 months.