Hepatocellular adenoma in the paediatric population: Molecular classification and clinical associations

Hepatocellular adenomas (HCAs) represent rare, benign liver tumours occurring predominantly in females taking oral contraceptives. In children, HCAs comprise less than 5% of hepatic tumours and demonstrate association with various conditions. The contemporary classification of HCAs, based on their distinctive genotypes and clinical phenotypes, includes hepatocyte nuclear factor 1 homeobox alpha-inactivated HCAs, beta-catenin-mutated HCAs, inflammatory HCAs, combined beta-catenin-mutated and inflammatory HCAs, sonic hedgehog-activated HCAs, and unclassified HCAs. In children, there is a lack of literature on the characteristics and distribution of HCA subtypes. In this review, we summarized different HCA subtypes and the clinicopathologic spectrum of HCAs in the paediatric population.

Men with biopsy-confirmed hepatocellular adenoma have a high risk of progression to hepatocellular carcinoma: A nationwide population-based study

BACKGROUND & AIMS

Hepatocellular adenoma is a benign liver tumour that may transform to hepatocellular carcinoma (HCC). We used data from Danish nationwide healthcare registries to investigate the incidence and prognosis of hepatocellular adenoma.

METHODS

We included all patients with a hospital discharge diagnosis for benign liver tumour (ICD-10: D13.4) in 1997-2012 and a liver biopsy confirming the hepatocellular adenoma diagnosis. Follow-up began 1 year after adenoma diagnosis, to minimise the possibility that the tumour was a misdiagnosed HCC. All patients were age- and gender-matched with 50 random controls from the Danish population. We followed patients and controls with respect to HCC development, adenoma resection, and death without HCC (ie, death without having been diagnosed with HCC) through 2013. HCC diagnoses were identified in the Danish Cancer Registry.

RESULTS

We included 67 patients with hepatocellular adenoma, and 58 (87%) were women. The overall incidence rate of histologically verified hepatocellular adenoma in the Danish general population was 0.07 (95% CI: 0.06-0.09) per 100 000 population per year. Fifteen patients had their adenoma resected before follow-up began, leaving 52 patients for follow-up. Men with biopsy-confirmed hepatocellular adenoma had a 10-year cumulative HCC risk as high as 60.0% (95% CI: 15.3%-87.0%). All men who developed HCC were older than 50 years at adenoma diagnosis. By contrast, none of the 44 women in the follow-up analysis developed HCC.

CONCLUSION

Histologically verified hepatocellular adenoma is rare in Denmark. It is a minor concern for women, but men have a very high risk of progression to HCC.

European experience of 573 liver resections for hepatocellular adenoma: a cross-sectional study by the AFC-HCA-2013 study group

BACKGROUND

Hepatocellular adenoma (HCA) is a benign hepatic lesion that may be complicated by bleeding and malignant transformation. The aim of the present study is to report on large series of liver resections for HCA and assess the incidence of hemorrhage and malignant transformation.

METHODS

A retrospective cross-sectional study, from 27 European high-volume HPB units.

RESULTS

573 patients were analyzed. The female: male gender ratio was 8:2, mean age: 37 ± 10 years. Of the 84 (14%) patients whose initial presentation was hemorrhagic shock (Hemorrhagic HCAs), hemostatic intervention was urgently required in 25 (30%) patients. No patients died after intervention. Tumor size was >5 cm in 74% in hemorrhagic HCAs and 64% in non-hemorrhagic HCAs (p < 0.001). In non-hemorrhagic HCAs (n = 489), 5% presented with malignant transformation. Male status and tumor size >10 cm were the two predictive factors. Liver resections included major hepatectomy in 25% and a laparoscopic approach in 37% of the patients. In non-hemorrhagic HCAs, there was no mortality and major complications occurred in 9% of patients.

DISCUSSION

Liver resection for HCA is safe. Presentation with hemorrhage was associated with larger tumor size. In males with a HCA >10 cm, a HCC should be suspected. In such situation, a preoperative biopsy is preferable and an oncological liver resection should be considered.

A biological effects monitoring survey of Cardigan Bay using flatfish histopathology, cellular biomarkers and sediment bioassays: findings of the Prince Madog Prize 2003

Cardigan Bay on the western coast of the UK is considered a pristine location with much of its coastal and marine habitats protected under various national and EC Directives. Despite this, populations of the flatfish dab (Limanda limanda) captured from Cardigan Bay display elevated levels of liver tumours relative to the background prevalence of the disease. This study describes the findings of a research cruise that took place during November 2003 to assess the prevalence of tumours in dab from selected sites in and around Cardigan Bay. In addition, potential causative mechanisms were investigated via measurement of a range of end points (including composition and abundance of benthic and phytoplankton communities, sediment toxicity and cellular biomarkers of genotoxicity) from sediment, water and biota samples. Fish captured from South Cardigan Bay displayed a relatively higher prevalence of liver tumours compared to those captured from Red Wharf Bay. Hepatocellular adenoma (8% and 2%, respectively) and hepatocellular foci of cell alteration (18% and 6%, respectively) were most prevalent in South Cardigan Bay. Analysis of the sediment failed to distinguish any differences in toxicity between the two sampling sites. However, DNA strand breaks in red blood cells of dab were significantly higher (p < 0.05) in fish collected from Red Warf Bay compared with those sampled at Cardigan Bay. The alignment of biological effects measures via such integrated cruise programs are discussed. This work was partly funded under the auspices of the 2003 Prince Madog Prize.

Body weight considerations in the B6C3F1 mouse and the use of dietary control to standardize background tumor incidence in chronic bioassays

In B6C3F1 mice, the rate of body growth influences susceptibility to liver neoplasia and large variations in body weight can complicate the interpretation of bioassay data. The relationship between body weight and liver tumor incidence was calculated for historical control populations of male and female ad libitum-fed mice (approx. 2,750 and 2,300 animals, respectively) and in populations of male and female mice which had been subjected to forced body weight reduction due to either dietary restriction or exposure to noncarcinogenic chemicals (approx. 1,600 and 1,700, respectively). Resulting tumor risk data were then used to construct idealized weight curves for male and female B6C3F1 mice; these curves predict a terminal background liver tumor incidence of 15-20%. Use of dietary control to manipulate body growth of male B6C3F1 mice to fit the idealized weight curve was evaluated in a 2-year bioassay of chloral hydrate. Cohorts of mice were successfully maintained at weights approximating their idealized target weights throughout the study. These mice exhibited less body weight variation than their ad libitum-fed counterparts (e.g., standard deviations of body weight were 1.4 and 3.4 g for respective control groups at 36 weeks). Historical control body weight and tumor risk data from the two male mouse populations were utilized to predict background liver tumor rates for each experimental group of the chloral hydrate study. The predicted background tumor rates closely matched the observed rates for both the dietary controlled and ad libitum-fed chloral hydrate control groups when each mouse was evaluated according to either its weekly food consumption or its weekly change in body weight.

Hepatoblastomas in mice in the US National Toxicology Program (NTP) studies

Over the last 8 years, a 5-fold increase in the incidence of mice with spontaneous hepatoblastomas and a moderate increase in the incidence of chemically induced hepatoblastomas in B6C3F1 mice occurred in 2-year NTP studies compared to the previous 7 years. There was a positive association between an increased incidence of mice with hepatoblastoma and an increased incidence of mice with hepatocellular tumors in the treated mice. The rate of pulmonary metastases for hepatoblastoma was similar to that of pulmonary metastasis for hepatocellular carcinomas. Although a variety of chemicals caused an increased incidence of mice with hepatoblastoma, there was no apparent association between a specific chemical structure or a biological class of compounds and their capacity to induce hepatoblastomas. Hepatoblastomas frequently arose within hepatocellular carcinomas or adenomas and were induced by the same compounds that induced hepatocellular neoplasms. Therefore, it seems reasonable to combine the incidence of mice with hepatoblastomas and the incidence of mice with hepatocellular carcinomas in hazard identification studies.

Comparative prevalence, multiplicity, and progression of spontaneous and vinyl carbamate-induced liver lesions in five strains of male mice

The overall and age-specific prevalences and multiplicities of spontaneous and chemically induced hepatocellular neoplasia were compared among male B6D2F1, B6C3F1, C3H (C3H/HeNCr1 MTV-), B6CF1, and C57BL/6 (C57BL/6NCr1) mice following a single intraperitoneal injection of 0.03 microM vinyl carbamate (VC)/g body weight or vehicle alone at 15 days of age. Additional groups of B6C3F1, C3H, and C57BL/6 males received 0.15 microM VC/g body weight at 15 days of age. For male B6D2F1, B6C3F1, C3H, B6CF1, and C57BL/6 mice, the estimated overall prevalences (and multiplicities) of hepatocellular adenomas or carcinomas in vehicle controls were 14.1% (0.19), 12.3% (0.15), 8.2% (0.10), 7.2% (0.09), and 2.4% (0.02), respectively. The analogous estimates in the low-dose group were 59.2% (1.19), 72.9% (4.07), 48.6% (1.99), 22.8% (0.29), and 43.9% (0.82). Analogous estimates for B6C3F1, C3H, and C57BL/6 mice in the high-dose group were 45.3% (4.29), 59.7% (6.63), and 46.8% (1.74), respectively. Age-specific multiplicity estimates suggested a progression from altered hepatocellular foci (AHF) to hepatocellular neoplasms. Further evidence of progression was provided by the temporal occurrence of hepatocellular adenomas before carcinomas, and the apparent origination of carcinomas within adenomas. Pulmonary metastases were observed in many of the mice with hepatocellular carcinomas. These findings confirm previous observations of strain differences in liver neoplasm response, suggest a progressive development from AHF to adenomas, and ultimately to carcinomas, and show sensitivity to VC-induced hepatocarcinogenesis in all 5 strains.

Benign and solid tumors of the liver: relationship to sex, age, size of tumors, and outcome

From 1983 through 1997, our center diagnosed 130 cases of benign neoplasms: 27 with focal nodular hyperplasia (FNH), 25 with hepatic adenoma, 71 with cavernous hemangioma, and seven with mixed tumors of different diagnoses. Most often these lesions were seen in females [female-to-male ratio (f/m): 5.5/1]. Hepatic adenomas and mixed tumors were seen exclusively in females and FNH predominantly in females (f/m: 26/1). Hemangiomas, however, were not uncommon in men (f/m: 52/19) relative to the other tumors (P < 0.001). Furthermore patients with hemangioma were older (mean age: 49 years) whereas patients with hepatic adenoma, FNH, and mixed tumors were often younger (mean age: 33, 35, and 44 years respectively; P < 0.004). Oral contraceptive steroid use was related by 21 of 25 patients (84%) with hepatic adenoma, 22 of 26 (85%) females with FNH, five of seven (71%) females with mixed tumors, and 10 of 52 (19%) patients with hemangioma. Ninety-five of the 130 patients (73%) had one or more symptoms. There was no statistically significant correlation between symptoms and the size of the lesion, the final diagnosis, and whether there were solitary or multiple masses. Three of 25 (12%) with hepatic adenoma presented with rupture, and one of 27 (4%) with FNH had such a consequence. None of the hemangiomas presented with rupture or progressed to such a state. One patient with hepatic adenoma (4%) had a focus of malignancy. Surgical removal of benign tumors was performed in 82 of 130 patients (63%), and there was one operative mortality (1.2%) in a patient who had a caudate lobe FNH. The types of surgical procedures included segmentectomy (62%), lobectomy (34%), and trisegmentectomy (4%). In two of 84 patients who had undergone laparotomy resection was not technically possible. Resection is recommended in all cases of hepatic adenoma because of fear of rupture or associated focus of malignancy. FNH was not observed to undergo a malignant transformation and will rarely rupture. Surgery is only recommended for symptomatic hemangioma, and size of the lesion is not a criterion for excision.

Calculation of the cumulative distribution function of the time to a small observable tumor

Multistage mathematical models of carcinogenesis (when applied to tumor incidence data) have historically assumed that the growth kinetics of cells in the malignant state are disregarded and the formation of a single malignant cell is equated with the emergence of a detectable tumor. The justification of this simplification is, from a mathematical point of view, to make the estimation of tumor incidence rates tractable. However, analytical forms are not mandatory in the estimation of tumor incidence rates. Portier et al.(1996b, Math. Biosci. 135, 129-146) have demonstrated the utility of the Kolmogorov backward equations in numerically calculating tumor incidence. By extending their results, the cumulative distribution function of the time to a small observable tumor may be numerically obtained.

A case of hepatocellular adenomatosis with a follow-up of 11 years

Hepatocellular adenomatosis is characterized by the presence of numerous (arbitrarily > 10) adenomas within an otherwise normal liver without a history of glycogen storage disease or steroid hormone therapy. Although the disease is rare, its importance lies in its tendency to produce symptoms such as abdominal pain and its potential for abdominal hemorrhages. However, the prognosis of hepatocellular adenomatosis remains uncertain. Here we describe the case of a 40-yr-old female with hepatocellular adenomatosis without evidence of serious complications, who was observed over a period of 11 yr.

Nonlymphomatous hepatobiliary masses in cats: 41 cases (1972 to 1991)

The medical and necropsy records of 41 cats diagnosed with nonlymphomatous hepatobiliary (NLHB) masses, including neoplasia and cysts, were reviewed. Overall, benign masses (n = 27) were more common than malignant ones (n = 14). The single most common malignancy was cholangiocellular carcinoma. The median age at diagnosis was significantly lower (P < .01) for cats with malignant rather than benign disease. Clinical signs associated with hepatobiliary neoplasia were usually vague and included lethargy, vomiting, and anorexia, often present for at least 2 weeks before presentation. Benign masses were an incidental finding in significantly more (P < .01) of the cases than were malignant masses. Median values for alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin were significantly higher (P < .05) in cats with malignant versus benign masses. The prognosis for malignant disease was poor, with 86% of the cats dying or being euthanatized during hospitalization. Cats with benign disease that underwent exploratory celiotomy were more likely to recover and warranted a more favorable prognosis than cats with malignant tumors. Factors associated with malignancy included age at presentation, presence of clinical signs at presentation, and specific serum chemistry changes.

Hepatic adenoma: report of three cases and review of the literature

Pathologically confirmed hepatic adenoma (HA) was observed in two women who were not using contraceptives and one 60-year-old man. All three cases had a mass in the right lobe of the liver and almost normal laboratory results. One case that had a movable pedunculated mass mimicked an extrahepatic tumor preoperatively, and two cases associated with acute abdominal pain resulting from intratumor hemorrhage were misdiagnosed as hepatoma and given interventional therapy prior to liver biopsy. In hepatic arterial DSA of two cases, the tumor appeared as hypervascular with peripheral blood supply and regularly parallel branches coursing centrally. On CT scans, the tumor appeared to be surrounded by a low-density ring in two cases, and an intratumor hyperdense area of fresh blood was noted in one case. Analysis of the three cases in this series and a review of the literature indicated that if the DSA and CT findings described above were revealed in a patient, particularly a young woman, with a mass of the right lobe of the liver (with or without acute abdominal pain) and normal laboratory results, HA should be strongly suspected, and CT-guided biopsy should be performed for pathological diagnosis, particularly when an equivocal diagnosis is made.

Hepatic adenoma: MR characteristics and correlation with pathologic findings

OBJECTIVE

The purpose of this study was to describe the MR appearance of hepatic adenomas and correlate the MR imaging features with pathologic findings.

MATERIALS AND METHODS

MR examinations were performed in 14 patients with 66 hepatic adenomas. The diagnosis of hepatic adenoma was proved pathologically in nine patients (22 lesions). In five other patients (44 lesions), who had type I glycogen storage disease and were known to be at risk for hepatic adenomas, the diagnosis was established by repeated sonographic examinations that showed stability, reduction, or resolution of hepatic tumors. T1- and T2-weighted spin-echo MR images obtained at 1.5 T were retrospectively reviewed for the signal intensity of the lesions relative to liver, the signal pattern, the presence of a capsule, and the presence of hemorrhage. Histopathologic specimens (22 lesions) were reviewed for fat content (graded 0-3), the presence of a capsule, and the presence of hemorrhage.

RESULTS

On T1-weighted images, 51 (77%) of 66 lesions were hyperintense, 11 (17%) were hypointense, and four (6%) were isointense with respect to liver. On T2-weighted images, 49 (74%) of 66 lesions were hyperintense, 12 (18%) were isointense, and five (8%) were hypointense. Sixty-one (92%) of 66 lesions were heterogeneous. Eleven (17%) of 66 lesions were hemorrhagic. Of the 22 lesions reviewed histopathologically, 17 were hyperintense on T1-weighted images; 15 of these had a fat content of grade 2 or 3 and two had hemorrhage. All 15 lesions that had a fat content of grade 2 or 3 were hyperintense on T1-weighted images.

CONCLUSION

Hepatic adenomas have a variable MR appearance but most often are hyperintense with respect to liver on T1- and T2-weighted images. The high signal intensity often relates to the increased fat content of these lesions.

Hepatocellular adenoma: color Doppler US and pathologic correlations

PURPOSE

To describe the color Doppler ultrasound (US) features of hepatocellular adenoma (HA) and correlate these findings with pathologic findings, with special emphasis on the blood vessels.

MATERIALS AND METHODS

Color Doppler US was prospectively performed in eight patients with histologic proof of HA. Eleven lesions were studied.

RESULTS

In seven lesions, color Doppler US demonstrated central color flow. In six of these lesions, pulse-wave Doppler US demonstrated a continuous and flat venous spectrum with frequency shifts of 0.20-0.60 kHz (mean, 0.37 kHz), which corresponded to pathologic findings of intratumoral veins 1-5 mm in diameter. The other lesion with central color flow demonstrated a triphasic venous waveform with 1.20-kHz frequency shift, which corresponded pathologically to a central vein 10 mm in diameter. In these seven lesions, color Doppler examination demonstrated both venous and arterial peritumoral flow.

CONCLUSION

Color Doppler US enables detection of intratumoral veins associated with peritumoral veins and arteries in patients with HA; these findings correlate well with pathologic data. These results might help in the differential diagnosis of HA and focal nodular hyperplasia.

Promotion of hepatocellular foci and adenomas by di(2-ethylhexyl) phthalate and phenobarbital in C3H/HeNCr mice following exposure to N-nitrosodiethylamine at 15 days of age

Previous studies have shown that phenobarbital (PB), as well as another known liver tumor promoter, alpha-hexachlorocyclohexane (HCH), inhibits hepatic tumor formation in infant N-nitrosodiethylamine (NDEA)-initiated C57BL/6 x C3H/He (B6C3F1) male mice. These inconsistencies in detecting PB and HCH as tumor promoters have raised important questions on the mechanism of tumor promotion in mice, as well as the reliability of the infant B6C3F1 mouse as an initiation model in two-stage carcinogenesis experiments. Therefore, in an effort to avoid the inconsistencies associated with the B6C3F1 mouse, the present study evaluated the ability of two known hepatic liver tumor promoters, di(2-ethylhexyl)phthalate (DEHP), a peroxisome proliferator, and phenobarbital (PB), a barbiturate, to promote hepatocellular tumorigenesis in mice of the C3H/HeNCr strain initiated during infancy. At 15 days of age, male and female C3H/HeNCr mice received either a single ip injection of NDEA (5 micrograms/g body weight) or saline. At weaning (4 weeks of age), mice were divided into 3 groups and treated with either DEHP in the diet (12,000 ppm), PB in the drinking water (500 ppm), or control drinking water and diet for 24 weeks. All mice were killed at 28 weeks of age and the number and size of hepatic foci and adenomas were evaluated. Mice exposed to NDEA+DEHP or NDEA+PB showed significant increases in the number and size of hepatic tumors compared to those receiving NDEA alone. DEHP treatment in males yielded larger adenomas than those seen in PB-treated males.(ABSTRACT TRUNCATED AT 250 WORDS)