Suspected focal nodular hyperplasia in male adults: 10-year experience from a large liver centre.

PURPOSE: Focal nodular hyperplasia (FNH) is commonly found in females of reproductive age. In males, the diagnosis is made more cautiously due to its lower incidence and higher incidence of hepatocellular carcinoma, which can have overlapping imaging features. Follow-up or biopsy is sometimes required. This retrospective study aims to assess management of suspected FNH in male adult patients at our institution over a 10-year period. METHODS: Male adults (≥ 18 years) suspected of having FNH from January 2010-June 2020 were identified using a departmental radiology information system search. Data was collected from radiology reports and patient pathway manager. RESULTS: Of 342 patients with suspected FNH, 62 were male (18.1%; F:M of 4.5:1). We only included patients investigated and followed up by MRI, total of 57 patients. Median age was 40 years (range 18-74 years). Background liver disease present in 21/57 (36.8%), majority with hepatic steatosis. Average number of lesions per patient 1.7. 22/57 (38.6%) had at least one MRI follow-up using liver-specific contrast with 7 lesions demonstrating variation in size (range growth: -3.27 mm/year to + 4 mm/year). In 7 cases, MRI was not definitive; 6 required biopsy and 1 resection. Only 2/7 demonstrated malignancy. Of the total 57 patients, 6 have deceased and none due to a misdiagnosed or mismanaged hepatic lesion. CONCLUSION: FNH is relatively uncommon in males, however, our data suggests that lesions with typical MRI characteristics do not require follow-up and diagnosis can be made confidently, similar to females. Any atypical features should prompt a biopsy.

Management of focal nodular hyperplasia of the liver: Experience of 50 pediatric patients in a tertiary center.

BACKGROUND: Focal nodular hyperplasia (FNH) is a rare benign hepatic lesion in children. No management guidelines for pediatric population exist because of limited evidence. OBJECTIVE: To review the experience of a large tertiary liver center, providing additional clinical data to help formulate management guidelines for FNH in the pediatric population. METHODS: We analyzed data of children <18 years diagnosed with FNH from 1996 to 2018 at our hospital, detailing management and long-term clinical outcome. RESULTS: 50 patients were identified. The median age was 10 years old (range 0.75-15.5 years old). The mean diameter of FNH was 5.9 cm (±3.1 cm). 10 patients had multiple lesions. First-line management: watchful waiting with serial checks (n = 37), surgery (n = 13). Of the watchful waiting patients, 10 required eventual second-line surgery. After a median follow-up of 4.7 years (range 0.5-20 years), 46 patients were asymptomatic, with no significant difference in clinical outcome (p = 0.962) between the two first-line management approaches. Lesions demonstrated growth in 13 cases: 5 of these required second-line surgery. In these patients, there was no significant difference in clinical outcome (p = 0.188) compared to nonoperative patients. Considering all surgically treated patients, there was no significant difference between first-line and second-line surgery for clinical outcome (p = 0.846), hospital stay (p = 0.410), complications (p = 0.510) and severe complications (p = 0.385). CONCLUSIONS: Our data support the hypothesis that watchful waiting is a safe initial approach to pediatric FNH management in patients with no major symptoms or complications. Surgery should be reserved for patients with diagnostic doubt, persistent symptoms and/or biological or significant anatomical abnormalities. FNH growth alone should not be considered as an indication for surgery. TYPE OF STUDY: Therapeutic study. LEVEL OF EVIDENCE: Level III.

Growth of hepatocellular adenoma during pregnancy: A prospective study.

BACKGROUND & AIMS: The presence of hepatocellular adenoma (HCA) in pregnant women requires special consideration, as it has been reported to carry the risk of growth and clinically significant haemorrhage. In this prospective study we assessed aspects of growth of HCA <5 cm during pregnancy. METHODS: This was a multicentre prospective cohort study in pregnant women with suspected HCA <5 cm on imaging. Definitive HCA diagnosis was established by MRI with hepatobiliary contrast agents (LCE-MRI), preferably before pregnancy. If at study inclusion a definitive diagnosis was lacking, LCE-MRI was performed after giving birth. Growth of the adenoma (defined as an increase of >20%) was closely monitored with ultrasound examinations throughout pregnancy. RESULTS: Of the 66 women included, 18 were excluded from analysis because postpartum LCE-MRI did not confirm the diagnosis of HCA and showed the lesion to be focal nodular hyperplasia. The remaining 48 women, with an HCA confirmed by LCE-MRI, were followed during 51 pregnancies. Median age was 30 years (IQR 27-33) and median body mass index 31.9 kg/m2 (IQR 26.3-36.6). Growth of HCA was seen in 13 of the pregnancies (25.5%); the median increase was 14 mm (IQR 8-19). One woman whose HCA grew to >70 mm successfully underwent transarterial embolization at week 26 of pregnancy to prevent further growth. The other 50 pregnancies proceeded without complications. CONCLUSION: This study suggests that an HCA <5 cm confers minimal risk to a pregnant woman and none to her child. HCA increased in size during a quarter of pregnancies, so we recommend close monitoring with ultrasound examinations, enabling intervention if needed. In light of the large proportion of misdiagnosed HCA, LCE-MRI should be performed to prevent unnecessary anxiety in women with a benign liver lesion. LAY SUMMARY: The presence of hepatocellular adenoma in pregnant women requires special consideration, as it carries the risk of growth and haemorrhage. In this study we followed 48 patients with hepatocellular adenoma <5 cm during 51 pregnancies and found that a hepatocellular adenoma during pregnancy confers minimal risk to the pregnant woman and none to her child.

Nodular Regenerative Hyperplasia of the Liver in Patients with IBD Treated with Allopurinol-Thiopurine Combination Therapy.

BACKGROUND: Thiopurine therapy, particularly thioguanine, has been associated with nodular regenerative hyperplasia (NRH) of the liver. Combination therapy of allopurinol and an adapted low-dose thiopurine leads to a pharmacokinetic profile that has similarities to that of thioguanine. Therefore, allopurinol-thiopurine combination therapy may also be associated with NRH of the liver. We assessed the prevalence of NRH in patients with inflammatory bowel disease (IBD) treated with allopurinol-thiopurine combination therapy by liver biopsy specimen examination. METHODS: An observational, cross-sectional study was conducted in a Dutch IBD-referral center. Adult patients with IBD, treated for at least 1 year with allopurinol-thiopurine combination therapy were eligible. All patients underwent a liver biopsy, after standard laboratory and thiopurine metabolite concentration assessments. Histopathology was assessed by an experienced liver pathologist. RESULTS: Twenty-two patients with IBD were included. The mean duration of combination therapy at the time of the liver biopsy was 24.7 months (SD 5.7). NRH was observed in one of the biopsies (4.8%), any grade of nodularity was observed in 3 biopsy specimens (14%). Other findings included phlebosclerosis (24%), perisinusoidal fibrosis (81%), sinusoidal dilatation (43%), perivenular fibrosis (14%), and periportal fibrosis (29%). Around the time of biopsy, the median 6-thioguanine nucleotide and 6-methylmercaptopurine ribonucleotide concentrations were 705 pmol × 10 red blood cells (RBC) (interquartile range 498-915) and 355 pmol × 10 RBC (interquartile range 225-670). CONCLUSIONS: The prevalence of histologically assessed NRH in patients with IBD, who were treated with allopurinol-thiopurine combination therapy, was 5%. This percentage is in line with thiopurine-naive and thioguanine-using patients with IBD. None of the included patients had clinical symptoms or signs suggestive of (noncirrhotic) portal hypertension.

Focal nodular hyperplasia: our experience of 53 Japanese cases.

PURPOSE: Contrast-enhanced ultrasound (CEUS) is a very sensitive diagnostic tool in characterizing liver tumors. It is especially useful in the diagnosis of focal nodular hyperplasia (FNH) of the liver. According to the previous reports, FNH is common in young women, and it is usually diagnosed by MRI. The majority of the previous reports come from European countries, and a very few studies of large series designed to describe the clinical features in Japanese patients have been reported. The aim of this study was to (a) describe the clinical features in 53 patients (59 lesions) diagnosed with CEUS and (b) compare the data with those from the previous reports. METHODS: The medical data from 53 patients diagnosed on the basis of typical CEUS findings at our institution and affiliated hospitals were reviewed, and their clinical data were analyzed. RESULTS: (1) The medical data from 53 cases showed a slight male predilection, with 30 male cases (57 %) and 23 female cases (43 %), although the occurrence in both sexes was equal. FNH cases were distributed throughout all generations in both sexes, mostly concentrated in the age of 30-60 years old, and metabolic cases were more common in men than in women (4 vs 0). (2) The lesions were small (mean: 23 mm) and distributed throughout the whole liver. (3) Lesion size was not influenced by age in either sex. (4) A rapid draining to the hepatic vein was recognized in five out of 59 lesions (8 %). CONCLUSIONS: Our data indicate that FNH occurs slightly more frequently in men than in women in Japan. It occurs also at any age in both sexes, but the mean lesion size was smaller in our series than in the previous reports. Metabolic disease was seen only in male FNH patients. A direct communication between the FNH lesion and the hepatic vein is diagnostically worth noting.

The Prevalence of Nodular Regenerative Hyperplasia in Inflammatory Bowel Disease Patients Treated with Thioguanine Is Not Associated with Clinically Significant Liver Disease.

BACKGROUND: Nodular regenerative hyperplasia (NRH) of the liver is associated with inflammatory-mediated diseases and certain drugs. There is conflicting data on the prevalence of NRH and its clinical implications in inflammatory bowel disease (IBD) patients treated with thioguanine. METHODS: A retrospective cohort study involving 7 Dutch centers comprised all IBD patients who were being treated with thioguanine and underwent a liver biopsy as part of the standard toxicity screening. Liver biopsy specimens were reviewed by 2 experienced liver pathologists. Clinical data as well as liver chemistry, blood counts, and abdominal imaging were collected. RESULTS: One hundred eleven IBD patients who submitted to liver biopsy were treated with thioguanine in a daily dose of 0.3 mg/kg for a median duration of 20 (4-64) months. NRH was detected in 6% of patients (7; 95% confidence interval, 3-14 patients). Older age (P = 0.02), elevated gamma-glutamyl transferase (P = 0.01) and alkaline phosphatase (P = 0.01) levels, a higher mean corpuscular volume (P = 0.02), and a lower platelet or leukocyte count (P < 0.01 and P = 0.02, respectively) were associated with NRH. Three of the 7 patients with NRH did not have any associated clinical symptoms or signs. The other 4 had minor biochemical abnormalities only. Ultrasonography revealed splenomegaly in 3 of the 78 patients (4%; 95% confidence interval, 0%-9%), only one of whom had NRH. There was no clinically overt portal hypertension. CONCLUSIONS: The prevalence of NRH was 6% in liver biopsies obtained from IBD patients treated with thioguanine. Histopathological irregularities including NRH were not associated with clinically significant findings over the period of observation.

Prevalence and clinical significance of nodular regenerative hyperplasia in liver biopsies.

BACKGROUND: Nodular regenerative hyperplasia (NRH) is a rare histological disorder associated with a wide variety of systemic diseases. AIMS: We aimed (i) to report the prevalence of NRH in a database of liver biopsies (LBs) and the frequency of portal hypertension (PHT) at diagnosis, and (ii) to investigate whether associated diseases and/or specific histological lesions, including abnormalities of the microvasculature, were related to PHT. METHODS: Patients with a histological diagnosis of NRH, referred by seven clinical departments, were retrospectively selected. Clinical, biological, radiological, haemodynamic and endoscopic data at diagnosis were recorded. LBs were reassessed for microvascular abnormalities. RESULTS: NRH was diagnosed in 4.4% of LBs (n = 159, male: 52%, mean age: 54). Among patients referred for unexplained liver enzyme abnormalities, 15% had NRH. PHT was present at diagnosis in 45 patients (38%), including 13 with portal thrombosis; 65% of patients had an associated disorder. Obliteration of portal vein branches, observed in the LBs of 17 patients (11%), was significantly associated with PHT (P = 0.02). Periportal angiomatosis, observed in 101 patients (63%), was associated with the absence of PHT (P < 10(-4) ). CONCLUSION: We suggest that NRH is a frequent histological lesion in the setting of unexplained liver enzyme abnormalities. PHT is present at the time of diagnosis in 1/3 of patients regardless of the presence of associated disease. The frequency of periportal angiomatosis in NRH without obliteration of portal vein branches, and its association with the absence of PHT suggest that obstructive portal venopathy would not represent the most frequent mechanism involved in NRH.

Lesiones hepáticas ocupantes de espacio / A hepatic space-occupying lesion

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Review article: the association between nodular regenerative hyperplasia, inflammatory bowel disease and thiopurine therapy.

BACKGROUND: Nodular regenerative hyperplasia (NRH) is increasingly being recognised in patients with inflammatory bowel disease (IBD). However, the pathogenesis and incidence of NRH in IBD, and the putative roles played by azathioprine (AZA), mercaptopurine (MP), or tioguanine (TG) remain unclear. AIMS: To summarise the data on the association between NRH and thiopurine therapy in patients with IBD. METHODS: A literature search was performed in PubMed and MEDLINE databases using the keywords 'nodular regenerative hyperplasia AND (inflammatory bowel disease OR Crohn's disease OR ulcerative colitis) AND (azathioprine OR mercaptopurine OR tioguanine OR thioguanine).' No time limit was placed on studies included. RESULTS: Inflammatory bowel disease patients treated with AZA have a cumulative incidence of NRH of approximately 0.6% and 1.28% at 5 and 10 years, respectively, whereas those treated with high-dose TG (>40 mg/day) have a frequency of NRH of up to 62%, which is higher in patients with elevated liver enzymes and/or thrombocytopaenia than those without these abnormalities (frequency 76% vs. 33%). Conversely, low-dose TG therapy (<20 mg/day) is relatively safe, with no cases of NRH observed. NRH has also been found in 6% of operated thiopurine-naïve IBD patients. Male gender, older age, and stricturing disease/small bowel resection have been consistently identified as high-risk factors for NRH. CONCLUSIONS: The pathogenesis of nodular regenerative hyperplasia in patients with IBD is complex and multifactorial involving disease-specific, genetic and iatrogenic risk factors. Clinicians should maintain a high index of suspicion for diagnosing nodular regenerative hyperplasia, especially in IBD patients with high-risk factors on thiopurine therapy, regardless of the presence of laboratory abnormalities.

Nodular regenerative hyperplasia in common variable immunodeficiency.

PURPOSE: Patients with Common Variable Immunodeficiency (CVID) are subject to the development of a liver disease syndrome known as nodular regenerative hyperplasia (NRH). The purpose of this study was to define the characteristics and course of this complication of CVID. METHODS: CVID patients were evaluated by retrospective and prospective clinical course review. Liver biopsy specimens were evaluated for evidence of NRH and studied via RT-PCR for cytokine analysis. RESULTS: NRH in our CVID patient population occurred in approximately 5 % of the 261 patients in our total CVID study group, initially presenting in most cases with an elevated alkaline phosphatase level. While in some patients the disease remained static, in a larger proportion a more severe disease developed characterized by portal hypertension, the latter leading to hypersplenism with neutropenia and thrombocytopenia and, in some cases, to ascites. In addition, a substantial proportion of patients either developed or presented initially with an autoimmune hepatitis-like (AIH-like) liver disease that resulted in severe liver dysfunction and, in most cases to death due to infections. The liver histologic findings in these AIH-like patients were characterized by underlying NRH pattern with superimposed interface hepatitis, lymphocytic infiltration and fibrosis. Immunologic studies of biopsies of NRH patients demonstrated the presence of infiltrating T cells producing IFN-γ, suggesting that the NRH is due to an autoimmune process. CONCLUSION: Overall, these studies provide evidence that NRH may not be benign but, can be a severe and potentially fatal disease complication of CVID that merits close monitoring and intervention.

Focal nodular hyperplasia and hepatocellular adenoma: current views.

Focal Nodular Hyperplasia (FNH) is a rare benign hepatic lesion believed to generate upon a hyperplastic response of the hepatocyte. Hepatocellular Adenoma (HA) occurs predominantly in young women receiving oral contraceptive medication. These two lesions have drawn significant attention throughout the recent years due to their specific clinical and pathological features as well as their challenging management. Although Focal Nodular Hyperplasia is managed conservatively in the majority of cases, it can albeit pose a difficult diagnostic dilemma. On the other hand, Hepatocellular Adenoma can be complicated with catastrophic hemorrhage or malignant transformation and therefore mandates surgical excision in many cases. The aim of this work is to review the current literature pertaining to these two clinical entities regarding their pathogenesis, diagnostic approach and genetics, as well as to shed light on specific differential diagnostic issues arising in many cases these lesions are encountered.

Benign hepatic nodular lesions after treatment for childhood cancer.

BACKGROUND: Benign nodular hepatic regenerating lesions such as focal nodular hyperplasia (FNH) have been reported as rare complications of the antineoplastic therapy received during infancy. Little is known about the risk factors associated with the onset of these lesions and their diagnostic management. METHODS: We have analyzed a series of benign hepatic nodular lesions occurring in children previously treated for malignant tumors in our institution in a period of 11 years. An extensive description of the imaging presentation of the lesions has been provided to facilitate the differential diagnosis, and a risk factor analysis has been conducted. RESULTS: A total of 14 diagnoses (10 FNH and 4 hemangiomas) of benign nodular hepatic lesions have been found. Hematopoietic stem cell transplantation is the most important statistically independent risk factor associated with the development of these lesions, especially for FNH. No malignant transformation of nodules has been recorded during a median follow-up time of 4 years. CONCLUSIONS: In our experience, FNH is the most frequent benign nodular hepatic lesions occurring after treatment for childhood cancer. Hematopoietic stem cell transplantation is the most important risk factor to be taken in account. After a secure diagnosis of these benign lesions, only a close imaging follow-up is recommended.

Incidence and etiology of new liver lesions in pediatric patients previously treated for malignancy.

OBJECTIVE: The purpose of this study was to retrospectively evaluate the time course, cause, and imaging characteristics of all new liver lesions in pediatric patients with a previously treated malignancy. MATERIALS AND METHODS: Our hospital cancer registry was used to identify patients between 1980 and 2005 who met the following criteria: solid tumor, survival > 2 years after diagnosis, no liver lesions at a posttreatment baseline, and cross-sectional imaging follow-up of > 2 years. Final dictated reports of all cross-sectional imaging examinations including the abdomen were reviewed for any mention of new liver lesions. Positive reports were followed by consensus review of the images and clinical data. Patients were divided into three groups: those with suspected or proven focal nodular hyperplasia (FNH), those with suspected or proven metastases, and those with other lesions. An exact Wilcoxon test was used to evaluate the differences between the groups. RESULTS: Of 967 patients who met the initial inclusion criteria, 273 had adequate follow-up to be included in the study. Forty-six patients (16.8%) developed new liver lesions during the study period, and 14 of those 46 were classified into the FNH group (30.4%) and seven were classified into the metastasis group (15.2%). A significant difference was found in the median time to the development of FNH versus metastasis and other lesions (FNH, 92.9 months; metastasis, 43.2 months; other lesions, 18.5 months; p < 0.0001). A significant difference was also seen in the median length of follow-up between the groups (FNH, 115.6 months; metastasis, 57 months; other lesions, 50.8 months; p = 0.002). The imaging features of the groups also differed. CONCLUSION: The most common liver lesion encountered in pediatric patients previously treated for malignancy was FNH, which occurred farther from the time of diagnosis and had different imaging characteristics from both metastases and other liver lesions.

Nodular regenerative hyperplasia: evolving concepts on underdiagnosed cause of portal hypertension.

Nodular regenerative hyperplasia (NRH) is a rare liver condition characterized by a widespread benign transformation of the hepatic parenchyma into small regenerative nodules. NRH may lead to the development of non-cirrhotic portal hypertension. There are no published systematic population studies on NRH and our current knowledge is limited to case reports and case series. NRH may develop via autoimmune, hematological, infectious, neoplastic, or drug-related causes. The disease is usually asymptomatic, slowly or non-progressive unless complications of portal hypertension develop. Accurate diagnosis is made by histopathology, which demonstrates diffuse micronodular transformation without fibrous septa. Lack of perinuclear collagen tissue distinguishes NRH from typical regenerative nodules in the cirrhotic liver. While the initial treatment is to address the underlying disease, ultimately the therapy is directed to the management of portal hypertension. The prognosis of NRH depends on both the severity of the underlying illness and the prevention of secondary complications of portal hypertension. In this review we detail the epidemiology, pathogenesis, diagnosis, management, and prognosis of NRH.

Incidence of nodular regenerative hyperplasia in inflammatory bowel disease patients treated with azathioprine.

BACKGROUND: Nodular regenerative hyperplasia (NRH) is a rare hepatic disorder that may lead to severe portal hypertension. Cases of NRH have been reported in patients receiving thiopurines for inflammatory bowel disease (IBD). Since azathioprine (AZA) is used more and more frequently as a maintenance treatment in IBD, the risk of NRH must be known. The objective of this study was to evaluate the prevalence of NRH and its predictive factors in IBD patients treated with AZA. MATERIALS AND METHODS: From the same tertiary referral center, 1888 consecutive IBD patients treated with AZA were studied. Clinical diagnosis of NRH was proven by liver biopsy in all cases except one. The cumulative risk of NRH was estimated with the Kaplan-Meier method. Factors associated with NRH were tested independently with the log-rank method and multivariate proportional hazards model with time-dependent covariates. RESULTS: Fifteen patients developed NRH in a median treatment duration of 52.4 months (SE 1.6). The cumulative incidence of NRH was 1.28±0.45% at 10 years. Only two variables were independently associated with NRH occurrence: male gender (P=0.0001, hazard ratio [HR] 8.5, 95% confidence interval [CI] 1.9-37.9) and small bowel resection≥50 cm (P<0.0001, HR 6.6, 95% CI 2.2-20.0), either prior to or after AZA initiation. CONCLUSIONS: The risk of developing NRH during AZA treatment is low. This study suggests that male patients with small bowel resection≥50 cm constitute the group with the higher risk of developing NRH while treated with AZA.

Pathology of pediatric liver tumors, a single center experience from south of Iran.

BACKGROUND: Pediatric hepatic malignancies are rare, accounting for 1-4% of all solid childhood tumors. The histopathology of childhood hepatic tumors guides the treatment and prognosis, and is the cornerstone for precise diagnosis. Until now, there has been no documented study on pediatric liver tumor cases from this center; in this report, we show our experience about the common types of childhood hepatic tumors during five years (2002-2007) and compare them with other studies. MATERIALS AND METHODS: During five years (2002-2007), all the hepatic tumors of childhood (under 18 year-old) from the pathology file of Namazi Hospital of Shiraz University of Medical Sciences are recorded. This includes both resected specimens and biopsies. All the slides were reviewed and the pathologic diagnosis was confirmed. RESULTS: We detected 53 liver tumor cases in children (below 18 years of age). Among these tumors, 36 (67.9%) were malignant. Male to female ratio was 1.5 to 1. Hepatoblastoma was the most common liver tumor in this age group accounting for 22 patients (41.5%). The second most common primary tumor was hepatocellular carcinoma (HCC), with five patients. Another malignant tumor was embryonal sarcoma. Benign tumors included adenoma, mesenchymal hamartoma, vascular tumors, focal nodular hyperplasia, and inflammatory pseudo tumor. There were also seven metastatic tumors during these five years. CONCLUSIONS: The spectrum of hepatic tumors in children is different from that found in the older age group (adults) and also different in different populations.

Management of benign hepatic tumors.

Advances in imaging techniques will dramatically decrease the number of undiagnosed tumors. New molecular techniques should allow the identification of pathologic factors that are predictive of complicated forms. Surgery should be limited to symptomatic benign tumors or those who have a risk for complication (hemorrhage, rupture, or degeneration). When surgery is indicated, patients with benign disease are the best candidates for laparoscopy.

Large spectrum of liver vascular lesions including high prevalence of focal nodular hyperplasia in patients with hereditary haemorrhagic telangiectasia: the Belgian Registry based on 30 patients.

OBJECTIVES: We report the Belgian Registry of 30 patients (19 women and 11 men) with hereditary haemorrhagic telangiectasia (HHT) and liver involvement. RESULTS: Twenty-three patients (77%) were asymptomatic. Within the seven symptomatic patients (23%), four suffered from high output cardiac failure, two died before liver transplantation and one was transplanted. Three patients developed symptomatic biliary disease, two were transplanted and one was listed. Intrahepatic shunts and a large hepatic artery (6-14 mm, mean: 9.3 mm) were found in all patients and are characteristic of liver involvement. We observed a high prevalence (47%) of asymptomatic hepatic tumours with radiological and histological characteristics of focal nodular hyperplasia (FNH) for the majority of these tumours. The histological examination of the three explanted livers revealed the coexistence of a large spectrum of hepatic vascular lesions including intrahepatic shunts, FNH, nodular regenerative hyperplasia, sinusoidal dilatation and ischaemic cholangiopathy. All these lesions should be diagnosed early to avoid invasive procedures even if a liver biopsy was performed in six of our patients without complications. The liver biopsy led to the diagnosis of HHT in one patient and to FNH in another one. CONCLUSION: Liver involvement in HHT is characterized by a high prevalence of FNH and a large spectrum of vascular lesions such as intrahepatic shunts, nodular regenerative hyperplasia, sinusoidal dilatation and ischaemic cholangiopathy that may coexist simultaneously in the same patient.

Focal nodular hyperplasia and hepatic adenoma: epidemiology and pathology.

Focal nodular hyperplasia (FNH) and hepatic adenoma (HA) represent the most frequent non-vascular benign liver tumors. They are often asymptomatic. The widespread use of high-resolution imaging modalities leads to an increase of incidental detection of FNH and HA. Physicians are thus increasingly confronted with these formerly rarely recognized conditions, stressing the need for concise but adequate information on the optimal clinical strategies for these patients. FNH is the most common non-vascular benign tumor of the liver. It probably arises as a polyclonal, hyperplastic response to a locally disturbed blood flow. It is typically found in asymptomatic women. Histologically, FNH can be described as a focal form of cirrhosis. Complications of FNH are extremely rare and surgical resection is generally not advised. HA is a rare monoclonal, but benign liver tumor primarily found in young females using estrogen-containing contraceptives. Although its exact etiology is unknown, a direct link between sex steroid exposure and the uncontrolled hepatocellular growth is suspected. Complications of HA are spontaneous bleeding and malignant transformation. Withdrawal of estrogen treatment and excision of large tumors (>5 cm) are established therapeutic strategies. In conclusion, although FNH and HA are reasonably well-described clinical and histopathological entities, their epidemiology and pathophysiology need to be further unraveled.