Renal sonogram of kidney for high bp showed no stenosis but showed a 4mm angiomyolipoma in the upper pole of kidney. should i see a nephrologist?

Not necessary: Angiomyolipomas are benign, it is small, and doing something about it would only cause problems when it is not causing any.

Angiomyolipomas : Although angiomyolipomas are benign lesions, i don't feel that that diagnosis can be conclusively reached by ultrasound alone. I would recommend that you have a contrast enhanced ct or mri.

Angiomyolipoma: A small angiomyolipoma of 4 mm does not require special care by a nephrologist. See a urologist. Be followed with ultrasound every 6 months to determine if it grows. An interventional radiologist can perform cryoablation of these or they can be removed surgically.