What do you notice about the two halves of this liver specimen? On the left, there’s normal parenchyma. A portal triad is seen in the middle, towards the bottom; the bile duct is at 11 o’clock. What’s seen in the right side is nothing but sheets of hepatocytes. This is typical of an adenoma.
Adenomas are associated with the use of oral contraceptives, so this patient should be advised to discontinue them. These lesions are also prone to growth, rupture and even transformation into hepatocellular carcinoma. Therefore, interval imaging is appropriate to delineate the growth trajectory. Lobectomy is indicated if the lesion grows beyond, say, 5 cm, or shows atypical enhancement patterns worrysome for malignant transformation.
The major differential diagnosis is focal nodular hyperplasia (FNH). A MRI with special contrast like Eovist or Multihance differentiates one from the next, with adenomas being hypointense in late phases and FNH being hyper or isointense on late phases.