Kidney Simple Cyst Bosniak I

A 62-year-old woman undergoes routine abdominal ultrasound for evaluation of vague right upper quadrant discomfort. She is a well-controlled type 2 diabetic with normal renal function (eGFR >60 mL/min/1.73 m²), clear urine dipstick, and no urinary symptoms. Ultrasound reveals a well-circumscribed, round, anechoic lesion measuring 32 mm in the right renal cortex (marked **A** in the diagram). The lesion demonstrates a hairline-thin wall without septations, no internal echoes, no mural nodules, and strong posterior acoustic enhancement. There is no internal color Doppler flow. Based on these imaging characteristics, what is the most appropriate management of the structure marked **A**?