Cortical adenoma in adrenohepatic fusion tissue: clue to making a correct diagnosis at preoperative computed tomography examination.

A 45-yr-old woman was admitted to excise a solid hepatic tumor which was incidentally detected at ultrasound examination for an unrelated reason. Preoperative differential diagnoses included primary or secondary malignant hepatic tumors or adrenal cortical carcinoma due to aggressive imaging features. The patient underwent adrenalectomy and partial hepatectomy. The tumor proved to be an adrenal cortical adenoma arising from the adrenohepatic fusion tissue and consisted of adenoma cells with lipid-rich cytoplasm. Retrospective review of preoperative computed tomography (CT) images demonstrated that the tumor measured 6 Hounsfield units in mean CT number and was continuous with a medial limb of the right adrenal gland.