A 33-year-old Hispanic female was admitted for left flank pain and presumed “pyelonephritis.” The patient had been healthy until two weeks prior to admission, when she noticed her left flank pain. The pain had been present since. The pain seemed to worsen with certain body movements. The patient did not complain of fever, nausea, or vomiting and she had no weight loss. She stated that she felt fine otherwise. The physical examination was completely normal except for mild to moderate left flank pain. Urinalysis, CBC, and routine chemistries were completely normal. Ultrasound images from the left kidney are shown below.
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Adrenal masses may be noted during ultrasonography of the kidney. In the present case, an ultrasound revealed a cystic mass clearly separated from the upper pole of the kidney. Lymphangiectatic cysts or cystic lymphangiomas are among the more common cystic adrenal tumors. Other cystic masses include pseudocysts and seromas secondary to hemorrhage. These cystic adrenal masses appear rather similar on ultrasound. The cystic lymphangioma in the present case is benign and surgical resection was indicated due to the patient’s complaint of flank pain.
Among the differential diagnoses given, an RCC is ruled out since the mass does not arise from the left kidney. Adrenal hematoma is unlikely because after two weeks it should show a partial seroma perhaps with some echogenic material. The mass lacks any characteristics of a large cyst ruling out a pedunculated renal cyst. An adrenal carcinoma is a viable differential diagnosis based on the ultrasound images.
This case was prepared by Raimund Hirschberg, MD, and Kamyar Kalantar-Zadeh, MD, PhD, of the Division of Nephrology & Hypertension, Harbor-UCLA Medical Center.