Adrenal Cortical Adenoma Developed in Adrenohepatic Fusion, a Mimicry of Hepatocellular Carcinoma - A Case Report -

Sun A Kim, Young-Joo Lee, Kyoung Won Kim, Gyungyub Gong
2011 The Korean Journal of Pathology  
Adrenohepatic fusion is characterized by the presence of a fragmented capsule or complete absence of capsular elements, allowing admixture of the parenchyma of the liver and adrenal gland. 1 The pathogenesis of adrenohepatic fusion could be either a developmental defect in formation of the periadrenal capsule, 2 or an acquired capsular defect from unknown causes. This is not an uncommon anatomic condition according to a large autopsy study. 3 However, an adrenal cortical adenoma in
more » ... oma in adrenohepatic fusion tissue has been encountered rarely and there are only a few reports that describe its clinicopathologic features. 4 Awareness of intrahepatic adrenocortical adenoma is important because radiologically and pathologically, it mimics hepatocellular carcinoma. Here we report a case of intrahepatic adrenal cortical adenoma arising in adrenohepatic fusion tissue, and we discuss its clinical implications. CASE REPORT A 59-year-old man was referred to our institute due to a hepatic mass discovered by computed tomography (CT) at an outside hospital during his regular medical check-up. He was pre-viously healthy without any symptoms. Laboratory investigations were unremarkable. Hepatitis B virus antigen and antihepatitis C virus antibody were all negative. The alpha-fetoprotein level (3.9 ng/mL) was within normal limits (normal value <20 ng/mL). Serum hormone levels were not checked because he had no hormone-related symptoms. Transabdominal ultrasonography revealed a bulging, low echoic mass at the posterior segment of the right hepatic lobe. On abdominal multiphasic dynamic CT with contrast enhancement, the mass showed slight hyperattenuation during arterial phase (Fig. 1A) and early washout during portal phase (Fig. 1B) . Based on this dynamic enhancement pattern, hepatocellular carcinoma was the primary suspect. Ultrasonography-guided needle biopsy of the mass followed. Polygonal cells with a clear microvesicular cytoplasm and a trabecular growth pattern suggested the diagnosis of a clear cell variant of hepatocellular carcinoma. The patient underwent right posterior segmentectomy of the liver. During the operation, the right adrenal gland was found to be adherent to the mass and the adjacent liver. Therefore, a part of the right adrenal gland was excised with the hepatic segment because it could not be separated from the liver by blunt dissection. The resected hepatic segment exhibited a well-de-Adrenohepatic fusion is the union of the liver and adrenal gland with close intermingling of their respective parenchymal cells. Adrenal cortical adenoma arising in adrenohepatic fusion tissue is extremely rare, although adrenohepatic fusion itself is relatively common. Here we report a case of a 59-year-old man with a mass in the right lobe of his liver. The mass showed slight hyperattenuation during arterial phase and hypoattenuation during portal phase on dynamic computed tomography with contrast enhancement. On pathology, the mass consisted of round to polygonal cells with clear microvesicular or eosinophilic cytoplasm, arranged in nests or in a trabecular pattern. The tumor cells were positive for inhibin and melan-A, but negative for Hep Par-1. In the periphery of the mass, adrenohepatic fusion was identified between the liver and adrenal gland, and was simultaneously resected with the mass. We report this rare case, and discuss its clinical implications, especially the differential diagnosis with hepatocellular carcinoma.
doi:10.4132/koreanjpathol.2011.45.2.196 fatcat:pyfixnc3oveg5p2r3gqvxzocfm