Thanks for your query.I will try to answer your query from point to point.
1) Your ultrasound
scan shows cortical cyst2-3 cms in size in your Rt kidney This may be accidental finding and seen in so many people.You do not need any treatment for the same as this is symptom less.
2)You are having increase frequency of urination this is due to combination of Diabetis and Prostatomegally.IS your diabetis well controlled?.If nor consult diabetologist
or Physicinan for proper medicines and dosage schedule
3).As regards your prostatomegaly
is 45 gm with postvoid urine of 50 cc which is significant.For this pl consult Urologist
.Since you are 55years old you can certainly try medicines You may start Tab Urimax -D once a day at night a.This will relieve your symptoms and improve the flow of urine and repeat Ultrasound scanning every 3 months to see the size and post void residue.Have a good luck .