Hepatic adrenal rest tumor presenting as a giant cystic lesion with regular wall nodule

Adrenal rest tumors are rare tumors at extra-adrenal sites that are derived from the heterotopic adrenocortical tissue. The frequency of hepatic adrenal rest tumors (HARTs) is exceedingly rare. Most reported HARTs are located under the capsule of segment VII and appear as a small well-circumscribed solid round mass with hypervascularity, a fatty component, and foci of calcification [1-7]. HARTs may be indistinguishable from hepatocellular carcinoma on imaging studies, which makes accurate preoperative diagnosis difficult.

A 56-year-old woman presented with an 8-month history of right upper abdomen distension and discomfort. She had no history of malignancy or chronic liver disease. Hepatitis viral markers were negative, and serum concentrations of alpha fetoprotein were within normal range. CT images showed a giant cystic lesion in the right lobe of the liver (Figure 1). A regular oval wall nodule had spotty calcifications along its anterior edge. The right adrenal gland was displaced and clearly demarcated from the tumor. The cyst wall and wall nodule demonstrated contrast enhancement. A right hemihepatectomy was performed. Immunohistochemical staining was positive for the adrenal cortical cell markers CD56, steroid growth factor-1, and inhibin-α; staining for chromogranin A was negative. The final histopathologic diagnosis was HART [1, 3, 8].

We report a rare atypical HART that differed from previously reported cases in terms of associated symptoms, size, and imaging characteristics [1-7]. Despite its rarity, this case highlights that HART should be considered in the differential diagnosis when a giant cystic liver lesion with regular wall nodule is encountered in the right lobe, especially in a patient with normal alpha-fetoprotein concentration.

Yu Liu: Writing - original draft (lead); resources (equal). Donghua Sun: Writing - original draft (equal). Heng Liu: Resources (equal); writing - review & editing (lead).

The authors declare no conflict of interest.

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