Adenomatose der Leber

Hepatic adenomatosis is the presence of numerous, more than 10 and up to 50, hepatic adenomas. It is a rare disorder, best characterized with MRI.

Epidemiology

Patients with hepatic adenomatosis do not necessarily have the classic risk factors associated with the development of hepatic adenomas, such as steroid or oral contraceptive use, or the presence of a glycogen storage disease. It has been reported to be more common in women .

Clinical presentation

Many patients are asymptomatic and the condition is discovered incidentally , but may present with abdominal pain from intraperitoneal hemorrhage.

Pathology

Gross pathology demonstrates multiple bulging nodules with prominent surface vascularity. The nodules are circumscribed but not encapsulated. Histology is similar to that of typical hepatic adenomas, with bland hepatocytes arranged in nodules that compress the adjacent normal parenchyma, extensive sinusoids and feeding vessels, and lack of biliary ductules.

Some have speculated that the development of adenomatosis may be associated with abnormal vascularization of the liver .

Radiographic features

The adenomas in adenomatosis may display imaging features differing from each other.

CT

• noncontrast: variable attenuation (increased attenuation with hemorrhage)
• arterial phase: variable enhancement, most sensitive postcontrast phase
• portal venous phase: variable enhancement, may be isoattenuating
• delayed phase: hypo- to isoenhancing
• intratumoral fat may be seen in some lesions
• coarse calcifications are possible (<5%), perhaps related to prior hemorrhage

MRI

• T1: isointense or hyperintense relative to liver
• T2: hyperintense
• T1 C+ (extracellular Gd):
  • arterial phase enhancement
  • variable portal venous and delayed enhancement, depending on the histologic type of adenoma
• T1 C+ (Eovist):
  • little to no delayed enhancement

Treatment and prognosis

Patients may have a progressive development of further adenomas. The adenomas are at risk of hemorrhage and are at risk for malignant degeneration of the adenomas into hepatocellular carcinoma.

There is no definitive therapy for adenomatosis and treatment depends on symptoms, imaging findings, and the number of adenomas. Symptomatic adenomas may be surgically resected or percutaneously ablated. Although it would often be inappropriate to resect/ablate every adenoma, liver transplantation has been performed for some patients with symptomatic widespread disease . The percentage of transplanted patients who unknowingly harbored hepatocellular carcinoma has been reported at 6% (2/32 patients) .

Differential diagnosis

• well-differentiated hepatocellular carcinoma with multiple intrahepatic metastases
• hepatic metastases
• hepatic epithelioid hemangioendothelioma (tends to be more confluent)

Siehe auch:

• Leberadenom
• adenomatöse Hyperplasie Leber

und weiter:

• Adenomatose