Hepatic Adenomatosis with Liver Steatosis

Hepatic adenomatosis is a rare disorder consists of multiple adenomas in the liver defined as separate clinical entity from hepatic adenoma. The number of adenoma is usually more than 10. Hepatic adenomatosis is not associated with intake of oral contraceptives, glycogen storage disease or anabolic steroid as the case with hepatic adenoma. What leads to its predisposition is not well understood and incompletely defined as most of the patients are asymptomatic. Some relate it to the hepatic vasculature abnormality (congenital or acquired). Patient may occasionally present with abdominal pain, increased liver size and slight elevation of serum alkaline phosphatase levels. Some patients with hepatic adenomatosis is found to have mutation in transcription factor 1 gene (TCF1) associated with MODY. Patients with multiple adenomas have frequently higher signs of fatty liver than single adenoma. Also, liver steatosis may play a key role in the development of these adenomas. One possible hypothesis is hyperplastic reaction of the hepatocyte and hepatic adenomas formation as a result of increase in the intracellular lipid component. Radiological appearance of hepatic adenomatosis is based on the size measurements and presence of hemorrhage, fat or water component. On sonography, smaller lesions are homogeneously hyperechoic and larger ones show mixed signal attenuation. CT scan shows hypodense lesions with peripheral enhancement on contrast administration. MRI often helps in the detection, characterization and differentiating various forms of hepatic adenomatosis. Hepatic adenomatosis exits in three forms, steatotic, peliotic and mixed. Each has different characteristics based on their morphology, histology and signal alterations on MRI. Steatotic form is slightly hyperintense on T2-weighted image, while iso-hyperintense on T1-weighted. They contain intralesional fat seen as signal dropout on opposed phase and on fat suppressed T-weighted image. These multiple lesions show arterial enhancement on gadolinium enhanced MRI with no persistent signal enhancement on delayed phase. Peliotic form which represent sinusoidal dilation are much larger, shows no signal dropout on fat suppression. The enhancement in arterial phase remains persistent on delayed phase as well. Mixed form is again much larger than its two forms. The T1-weighted signal intensity is variable (combined imaging features of above two forms). Contrast enhancement in mixed form is similar to peliotic. Differential diagnosis includes FNH, metastasis, multicenteric HCC. Each one has its own characteristic feature. However, imaging alone can’t differentiate hepatic adenomatosis. Biochemical and histopathology correlation is often required. Hepatic adenomatosis have higher incidence of hemorrhage and malignant degeneration. In consideration, surgical resection is recommended in a solitary lesion which is large > 5cm, exophytic and hemorrhagic. Continuous monitoring and follow up is advised in cases of multifocal adenomas where surgery intervention is not possible. Patient with life-threatening bleeding can be the suitable candidate for embolization. Genetic testing and counseling can be performed in case of family history of diabetes.