Type:
Educational Exhibit
Keywords:
Education and training, Imaging sequences, Biopsy, MR-Diffusion/Perfusion, MR, CT, Liver, Abdomen
Authors:
J. Niza1, M. Palmeiro2, E. M. Abreu3, A. Loureiro1, C. Oliveira3; 1Lisboa/PT, 2Queluz/PT, 3Lisbon/PT
DOI:
10.1594/ecr2013/C-2620
Background
Hepatocellular adenomas are rare,
benign tumors of cells closely resembling to normal hepatocytes.
These tumors are seen predominantly in young women,
especially when using oral contraceptive pills.
They can be located in the right or left hepatic lobe,
and are typically solitary (70-80%).
(3) Multiple adenomas have been described in patients with prolonged contraceptive use and glycogen storage diseases (GSD),
in which case we speak of hepatocellular adenomatosis.
(1) Hepatocellular adenoma can also be found in men who are receiving anabolic steroid therapy.
(2)
The close relationship between oral contraceptive medication and HCA has been described the first time in 1973 by Baum.
This casual relationship appears to be proportional to the hormonal dose and duration of medication and is highest in women over 30 years of age after using oral contraceptives for more than 24 months.(1) In women who have never used oral contraceptives,
the annual incidence of hepatic adenoma is about 1 per million.
It increases to 30–40 per million in long-term users of oral contraceptives.
(3)
Hepatocellular adenoma can reach up to 30 cm in diameter.
The clinical presentation of the HCA usually includes
abdominal pain,
hepatomegaly and abnormal liver functions.(2)
Pathologically speaking the HCA usually appears as a smooth,
well circumscribed mass that has a fleshy appearance.
Having large blood vessels on the surface they sometimes outgrow their arterial blood supply causing necrosis within the lesion.
The most common complication of HCA is intratumoral or intraperitoneal hemorrhage,
which occurs in 50-60% of patients.
Besides,
there is also the risk of malignant transformation that can be as high as 13%.
(3) Due to this and to the fact that this lesion may be difficult to distinguish from other benign or malignant hepatic tumors it is extremely important to the physicians to have a good characterization of these tumors through the correlation of imaging features and histopathology.