Diagnostic challenges associated with adrenocortical neoplasms arising from adreno-hepatic fusion: a case report of two patients and a literature review.

Background: A right adrenal gland may present in the form of adreno-hepatic fusion (AHF), in which the adrenal cells are interspersed among the hepatocytes without septation. This rare, naturally-occurring phenomenon may be associated with preoperative misdiagnosis. We present two cases of adrenal tumor in patients with AHF that were misdiagnosed, despite thorough preoperative work-ups. The findings emphasize the importance of suspecting adrenal tumor arising in AHF for lesions at the periphery of liver segment 7, even when located inside the liver. In addition, AHF can resemble malignant invasion on preoperative images, which further complicates the initial diagnosis.

Case Description: A 44-year-old woman presented with a 3-cm fat-enriched intrahepatic tumor at the periphery of segment 7. Preoperative biopsy revealed a possible angiomyolipoma or epithelioid cell neoplasm that was negative for arginase-1 and hepatocyte markers and positive for smooth muscle actin (SMA). During liver tumorectomy, a severe adhesion to the right adrenal gland was identified. The final diagnosis was an adrenocortical neoplasm with Weiss score 2 that had arisen in AHF. A second patient, a 67-year-old man had a hypoattenuating 4-cm lesion of his right adrenal gland with irregular borders to the liver, suggesting liver invasion on computed tomography. Positron emission tomography (PET) showed a mild hypermetabolic nodule, but did not suggest malignancy. However, because adrenocortical carcinoma was suspected due invasive features, right adrenalectomy with liver tumorectomy was performed as an resection. The final diagnosis was an adrenocortical neoplasm with Weiss score 2 that had arisen in AHF. Both patients showed no further evidence of disease ≥1 year of following surgery.

Conclusions: AHF-related adrenal lesions are often associated with diagnostic challenges, potentially resulting in misdiagnosis. We presented for the first time that adrenal lesions can be SMA-positive, which complicated the initial diagnosis of the first patient. Moreover, PET scans may help differentiate such lesions from malignancy, especially when invasive features are suspected. Alongside a review of 16 similar cases in the literature, our experience with these patients underscores the importance of initially considering AHF in the differential diagnosis of adrenal tumor adjacent to the liver.