Malignant Transformation of Liver Adenoma: An Analysis of the Literature

Abstract

As adenoma in other locations, hepatic adenoma (HA) may transform into hepatocellular carcinoma (HCC) and hepatocyte dysplasia is most probably the intermediate step between both conditions. Malignant HA may appear as microscopic or macroscopic areas of HCC within the HA. These areas are typically well differentiated and without vascular extension or satellite nodules. AFP measurements are not reliable as they are usually normal. The risk of malignant transformation of HA cannot be reliably quantified yet. Several series are concordant to show that approximately 5% of patients whose HA have been resected had pathological evidence of HCC within their HA. This figure however does not take into account fully transformed HA where evidence of the preexisting benign lesion might have disappeared. The risk of malignant transformation is correlated with the diameter of the HA and it is very unusual when it is <5 cm and the same holds true for patients with multiple HA. These results suggest that small HA could be safely observed as they are also at low risk of bleeding. These conclusions might not apply to male patients who are at lower risk of HA, except in specific conditions, but appear to be at a much higher risk of malignant changes.

Synchronous giant hepatic adenoma in siblings-A case report and brief literature review

“…The main complications of HA are rupture, hemorrhage and malignant transformation, the incidence of which increase with increasing adenoma size. 8,9 For giant HAs, surgical excision at an experienced liver surgery unit is the gold standard treatment option. 1 Our literature review also indicates that this is the first report of HA in siblings.…”

Primary and Metastatic Tumours of the Liver: Expanding Scope of Morphological and Immunohistochemical Details in the Biopsy

“…Rupture and bleeding (40%) represent dangerous complications [27,[29][30][31]; the risk of these events is increased in pregnant ladies affected by liver cell adenoma due to prior use of hormonal contraceptives. Risk of malignant transformation also is recognised [29,32]. By literature analysis, Farges and Dokmak concluded that 5% of resected hepatic adenomas bear HCC foci [32].…”

“…Risk of malignant transformation also is recognised [29,32]. By literature analysis, Farges and Dokmak concluded that 5% of resected hepatic adenomas bear HCC foci [32]. The risk of malignant transformation is higher in adenomas exceeding the size of 5 cm irrespectively of the number of adenomas as well as in males.…”

Extrahepatic Metastasis of Hepatocellular Carcinoma Arising from a Hepatic Adenoma without Concurrent Intrahepatic Recurrence

“…Hepatic adenomas are benign neoplasms of the liver that lack normal hepatic architecture 1 . They are usually rare in men, primarily affecting women of reproductive age who have a history of oral contraceptive pill use and people with exposure to androgens or anabolic steroids 2 .…”

“…Compared with intrahepatic recurrence, extrahepatic metastasis is relatively low in incidence, but has a worse prognosis 1 .The most common sites of extrahepatic metastasis are lungs, lymph nodes, bones, and adrenal glands. When hcc metastasizes to bone, it most commonly involves the vertebrae, ribs, and long bones.…”