Hepatocellular adenomas (HCAs) are rare benign liver tumours. Predisposing factors and complication rates appear to differ among children and adults. In the present study, we aimed to systematically characterise paediatric HCAs and determine their course, complications, and management. Medical history, clinical symptoms, imaging, histopathology, and genetics of children with HCAs were collected through a systematic and comprehensive review of the published literature. A total of 316 children with HCAs were included in the present study. HCAs were diagnosed primarily in girls (59.3%) and at a mean age of 11.5 (range 0-17.7) years. The majority (83.6%) of HCAs occurred in children with predisposing diseases, of which glycogen storage disease was the most common, followed by portosystemic shunts and MODY3 (maturity-onset diabetes of the young type 3). Each of these diseases leads to a well-defined HCA molecular pattern. A significant number of HCAs either bled (24.7%) or transformed (14.8%) over time. HCA transformation was significantly more frequent in children with portosystemic shunts and in β-catenin-mutated HCAs, while haemorrhages were more frequent in children exposed to hormones and those with larger lesions. Management was primarily guided by any predisposing conditions and the number of lesions. Therefore, vascular shunts were closed when possible, while complicated lesions were resected. Liver transplantation has made it possible to treat adenomatosis, as well as any underlying diseases. Progress in understanding genetic and/or malformative contributions, which appear to be significant in paediatric HCAs, have provided insights into tumour pathogenesis and will further guide patient surveillance and management.

OBJECTIVE: To explore the role of progestins as potential contributing factors for the development of hepatocellular adenoma (HA) METHODS: We describe 3 cases of adolescents and young adults who developed HA while on norethindrone (NET), as well as their management. In addition, we provide a comprehensive literature review on the association between progestins and HA.
RESULTS: Since 1983, 16 cases of HA in patients on progestins have been reported. Ten patients were on NET and 5 on a prodrug of NET (4 on norethindrone acetate [NETA] and 1 on lynestrenol). One individual had a norgestrel implant. Eight subsequently ceased all hormones: 4 experienced a size reduction, and 3 had complete resolution of their HA. Among our patients, 1 ceased NET and instead had a levonorgestrel intrauterine device inserted, and another swapped from NET to oral medroxyprogesterone acetate. Both experienced complete resolution of their HA. The third ceased NET and underwent a hysterectomy, with size reduction of her HA.
CONCLUSIONS: These cases and the literature review suggest an association between progestin exposure, in particular NET and its prodrugs, and the development of HA. The pathophysiology is unknown but may include peripheral conversion of NET and NETA to ethinyl estradiol or a specific action of 19-nortestosterone derivatives on hepatocytes, especially those with higher systemic doses compared with the levonorgestrel intrauterine device. There are no case reports relating to other forms of progestins, such as 17-hydroxyprogesterone, which may be important when considering alternative therapeutic options in females requiring effective menstrual management who have comorbidities.