Focal nodular hyperplasia of the liver: an unusual association with diabetes mellitus in a child and review of literature

Benign paediatric liver tumours: The radiological maze demystified

The trajectory from the clinical identification of a benign liver mass to establishing a precise diagnosis is perplexing and arduous. Related contributory factors are that such lesions are encountered infrequently and that there is a nonavailability of dedicated paediatric radiologists in the developing world. The objective of this study was to review the spectrum of benign liver lesions in children and their typical imaging features. Cross-sectional imaging of all paediatric patients (< 18 years) with liver lesions (single and multiple) performed in the institute from 01 January 2018 to 01 January 2019 as well as those acquired at outside institutions and referred to the institute for management was included. Ultrasound was done as the first line of investigation in all the cases with suspicious liver masses and retrospectively performed in referral cases in whom CT or MRI was already done. Images were analysed by two senior radiologists. Most of the cases were diagnosed based on clinical, biochemical and imaging findings, and biopsy was only performed in equivocal cases. Most of the benign liver lesions in the paediatric age group were hepatic haemangioma and mesenchymal hamartomas. A simplified clinical-radiologic paradigm should be established for benign liver lesions in children to assist in reaching the correct diagnosis.

Contribution

The article demonstrates the salient radiological findings of various benign liver lesions in the paediatric age group and the role of demographic, clinical and biochemical findings, which plays a substantial role in the diagnosis and avoids unnecessary biopsies.

Benign liver tumors in pediatric patients - Review with emphasis on imaging features

Benign hepatic tumors are commonly observed in adults, but rarely reported in children. The reasons for this remain speculative and the exact data concerning the incidence of these lesions are lacking. Benign hepatic tumors represent a diverse group of epithelial and mesenchymal tumors. In pediatric patients, most benign focal liver lesions are inborn and may grow like the rest of the body. Knowledge of pediatric liver diseases and their imaging appearances is essential in order to make an appropriate differential diagnosis. Selection of the appropriate imaging test is challenging, since it depends on a number of age-related factors. This paper will discuss the most frequently encountered benign liver tumors in children (infantile hepatic hemangioendothelioma, mesenchymal hamartoma, focal nodular hyperplasia, nodular regenerative hyperplasia, and hepatocellular adenoma), as well as a comparison to the current knowledge regarding such tumors in adult patients. The current emphasis is on imaging features, which are helpful not only for the initial diagnosis, but also for pre- and post-treatment evaluation and follow-up. In addition, future perspectives of contrast-enhanced ultrasound (CEUS) in pediatric patients are highlighted, with descriptions of enhancement patterns for each lesion being discussed. The role of advanced imaging tests such as CEUS and magnetic resonance imaging, which allow for non-invasive assessment of liver tumors, is of utmost importance in pediatric patients, especially when repeated imaging tests are needed and radiation exposure should be avoided.

Focal nodular hyperplasia of the liver: an emerging complication of hematopoietic SCT in children

Hepatic focal nodular hyperplasia (FNH) is a nonmalignant condition rarely affecting children previously treated for cancer, especially those who received hematopoietic SCT (HSCT). Some aspects of its pathogenesis still remain unclear and a strong association with specific risk factors has not yet been identified. We report here a single institution's case series of 17 patients who underwent HSCT and were diagnosed with FNH, analyzing retrospectively their clinical features and the radiological appearance of their hepatic lesions. We aimed to compare the diagnostic accuracy of ultrasound (US) and magnetic resonance imaging (MRI) and to explore the role of transient elastography (FibroScan) to evaluate the degree of hepatic fibrosis in FNH patients. Our analysis showed an association of FNH with age at transplant ⩽12 years (hazard ratio (HR) 9.10); chronic GVHD (HR 2.99); hormone-replacement therapy (HR 4.02) and abdominal radiotherapy (HR 4.37). MRI proved to be a more accurate diagnostic tool compared with US. Nine out of 12 patients who underwent FibroScan showed hepatic fibrosis. Our study points out that FNH is an emerging complication of HSCT, which requires a lifelong surveillance to follow its course in cancer patients.

Focal nodular hyperplasia on accessory lobe of the liver: preoperative diagnosis and management

We report the case of a 13 year-old girl transferred to our department with a one month history of vomiting, weight loss, and abdominal mass that was diagnosed as Focal Nodular Hyperplasia in an accessory lobe of the liver. Accessory liver lobe is a rare congenital anomaly whose preoperative diagnosis is difficult and usually presents as an incidental finding intraoperatively. Depending on their location and size, they can present as acute abdomen or abdominopelvic mass. In the literature reviewed, we found no association of focal nodular hyperplasia and accessory liver lobe in children.

Current concepts in pediatric liver tumors

Liver tumors in children can be classified into benign or malignant; some of the benign lesions can have the potential of malignant transformation, and therefore the therapeutic approach may change. These neoplasms account for nearly 1-2% of all pediatric tumors and they have gained significant attention in the last decades due to data suggesting that the incidence may be increasing 5% annually. We know that with new and improved imaging modalities some of these lesions may be detected more often than before. Recent studies showed that liver cancer represented 2% of malignancies in infants by 1980s and this was doubled in incidence to 4% in the following 10 yr. In this review our aim is to discuss all primary liver tumors in children with attention to their clinicopathological and immunohistochemical features followed by the current standard of care.

Comparative histomorphological review of rat and human hepatocellular proliferative lesions

In this comparative review, histomorphological features of common nonneoplastic and neoplastic hepatocyte lesions of rats and humans are examined using H&E-stained slides. The morphological similarities and differences of both neoplastic (hepatocellular carcinoma and hepatocellular adenoma) and presumptive preneoplastic lesions (large and small cell change in humans and foci of cellular alteration in rats) are presented and discussed. There are major similarities in the diagnostic features, growth patterns and behavior of both rat and human hepatocellular proliferative lesions and in the process of hepatocarcinogenesis. Further study of presumptive preneoplastic lesions in humans and rats should help to further define their role in progression to hepatocellular neoplasia in both species.

[Focal nodular hyperplasia in a 12-year-old boy: case report and considerations]

BACKGROUND

Focal nodular hyperplasia (FNH) is a benign hepatic tumor of unknown origin. It is only observed rarely in children (approximately 1-2% of all pediatric liver tumors).

CASE REPORT

A 12-year-old boy who suffered from infectious mononucleosis with liver involvement and hepatomegaly underwent a sonographic scan of the liver at an external hospital 3 months after the infection disappeared which revealed a tumor of the left hepatic lobule. Subsequent further examination (abdominal CT and MRT scans) confirmed the diagnosis of a highly vascularized mass about 10 cm in diameter, suspicious for FNH. Due to the high vascularization no biopsy was performed. A preoperative angiographic coiling and complete surgical resection was carried out because of the size and morphologic uncertainty. The diagnosis of FNH was confirmed by histological examination. The annual sonographic examination at follow-up has been uneventful for a 4-year period.

CONCLUSIONS

Due to the rarity the diagnosis of FNH in children can be difficult leading to differential diagnostic problems. Due to the risk of bleeding in larger size tumors a biopsy is a point of controversy. Complete resection and histopathological examination of FNHs in childhood is a mandatory therapeutic option, which may be indicated in large tumors or, as in the present case tumors of uncertain biological behaviour.