A middle aged woman underwent ultrasound examination for vague low abdominal / pelvic pain.
The right kidney is normal. Superior to the kidney and inferior to the liver is a bilobed, echogenic mass which does not demonstrate any doppler flow. The position is suggestive of an adrenal mass.
There is a round, hetrogenous mass in the lower pole of the left kidney, suspicious of a renal cell carcinoma or metastases.
There was an incidental, small left ovarian dermoid (not shown).
Adrenal masses are not uncommon (1-2% of the population). Approximately 2/3 are benign, although benign lesions may still be important if they are functional (e.g. pheochromocytoma or adenoma causing Cushing's or Conn's syndromes).
The finding of the left renal mass made the diagnosis of metastatic disease almost certain in this case. No other abnormality was found on scanning the rest of the abdomen. Subsequent investigation confirmed the diagnosis of renal cell carcinoma with adrenal metastases.
When scanning for pelvic pain, referred pain from the kidneys should always be considered (although it was uncertain in this case whether these lesions caused the patient's symptoms).