Hepatocellular adenomatosis is a rare entity that may mimic other hepatocellular lesions

A 14-year-old girl presented to her pediatrician with right lower quadrant pain that progressed to right upper quadrant pain with radiation to her back. Her past medical history included mitral valve prolapse, and she had no history of oral contraceptive use. Abdominal computed tomography revealed a liver mass and multiple smaller areas of low attenuation, too small to characterize. The clinical and radiographic features were suggestive of hepatocellular adenoma, and she underwent a left hepatic lobectomy. The liver contained one 4.2 cm nodule and multiple (10 to 20) smaller nodules that were well-demarcated from the adjacent liver parenchyma. All lesions were histologically hepatocellular adenomas and, therefore, she was diagnosed with hepatocellular adenomatosis. This case is unique because of the small number of cases of hepatocellular adenomatosis diagnosed in teenagers, and little long-term follow-up.