My CT scan says: 1. ...There is a well-defined 1.5 cm lucent lesion in the posterior left ilium at the sacroiliac joint, which may represent a degenerative cyst . 2. Subcentimeter periaortic lymph nodes at the level of the renal arteries. 3. Tiny nonenhancing cyst is present in the right posterior kidney measuring 5 cm. Would you, please, give me some ideas? Thank you in advance.