The clinical course in pediatric solid tumor patients with focal nodular hyperplasia of the liver

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.

Hepatic focal nodular hyperplasia after pediatric hematopoietic stem cell transplantation: The impact of hormonal replacement therapy and iron overload

BACKGROUND

The advent of techniques for the assessment of iron overload (liver T2*-MRI) has led to the awareness that focal nodular hyperplasia (FNH) represents a possible incidental finding after hematopoietic stem cell transplantation (HSCT), though its pathogenesis is still unclear.

METHODS

We performed a retrospective analysis of the liver T2*-MRI scans performed between 2013 and 2018 in a single pediatric HSCT Unit and recorded the number of patients with FNH (group A). Patients incidentally diagnosed with FNH at imaging performed for different clinical indications were included in group B.

RESULTS

Nine of 105 (8.6%) patients from group A were diagnosed with FNH. Group B included three patients. Overall, 12 patients were diagnosed 4.4 ± 3.1 years after HSCT. At univariate analysis, female gender (odds ratio [OR] 3.77, P = .03), moderate-to-severe iron overload (OR 6.97, P = .01), and hormone replacement therapy (HRT) administered for at least 6 months (OR 18.20, P = .0002) exposed patients to a higher risk of developing FNH. The detrimental effect of HRT was significant also at multivariate analysis (OR 7.93, P = .024). MRI-T2* values in affected patients were statistically lower than healthy controls (P < .001).

CONCLUSIONS

We confirm the high incidence of FNH among transplanted pediatric patients and demonstrate the potential pathogenic role of HRT and iron overload.

Late Effects and Survivorship Issues in Patients with Neuroblastoma

Over the past two decades, marked progress has been made in understanding the biology of neuroblastoma; this has led to refined risk stratification and treatment modifications with resultant increasing 5-year survival rates for children with neuroblastoma. Survivors, however, remain at risk for a wide variety of potential treatment-related complications, or "late effects", which may lead to excess morbidity and premature mortality in this cohort. This review summarizes the existing survivorship literature on long-term health outcomes for survivors of neuroblastoma, focusing specifically on potential injury to the endocrine, sensory, cardiovascular, pulmonary, and renal systems, as well as survivors' treatment-related risk for subsequent neoplasms and impaired quality of life. Additional work is needed to assess the potential late effects of newer multimodality therapies with the aim of optimizing long-term medical and psychosocial outcomes for all survivors of neuroblastoma.

Hepatic metastatic disease in pediatric and adolescent solid tumors

The management of hepatic metastatic disease from solid tumors in adults has been extensively described and resection of metastatic liver lesions from colorectal adenocarcinoma, renal adenocarcinoma, breast cancer, testicular cancer, and neuroendocrine tumors (NET) have demonstrated therapeutic benefits in select patients. However, there are few reports in the literature on the management of hepatic metastatic disease in the pediatric and adolescent populations and the effectiveness of hepatic metastasectomy. This may be due to the much lower incidence of pediatric malignancies and the higher chemosensitivity of childhood tumors which make hepatic metastasectomy less likely to be required. We review liver involvement with metastatic disease from the main pediatric solid tumors, including neuroblastoma and Wilms tumor focusing on the management and treatment options. We also review other solid malignant tumors which may have liver metastases including germ cell tumors, gastrointestinal stromal tumors, osteosarcoma, desmoplastic small round cell tumors and NET. However, these histological subtypes are so rare in the pediatric and adolescent populations that the exact incidence and best management of hepatic metastatic disease are unknown and can only be extrapolated from adult series.

Diagnosis and management of solid benign liver lesions

More and more asymptomatic benign liver tumours are discovered incidentally and can be divided into regenerative lesions and true neoplastic lesions. The most common regenerative lesions include hemangioma, focal nodular hyperplasia and inflammatory pseudotumours of the liver. Neoplastic lesions include hepatocellular adenomas and angiomyolipomas. Regenerative lesions rarely increase in volume, do not yield a higher risk of complications and usually do not require treatment. By contrast, hepatocellular adenomas and angiomyolipomas can increase in volume and are associated with a risk of complications. Large hepatocellular adenomas (>5 cm in diameter) are undoubtedly associated with a risk of bleeding and malignant transformation, particularly the inflammatory (also known as telangiectatic) and β-catenin mutated subtypes. Accurate diagnosis needs to be obtained to select patients eligible for surgical resection. MRI has markedly improved diagnosis and can identify the major hepatocellular adenomas subtypes. The use of biopsy results to inform the indication for resection remains questionable. However, when diagnosis remains uncertain after imaging, percutaneous biopsy could help improve diagnostic accuracy.

Differential diagnosis and management of liver tumors in infants

During the first year of life, most of the liver neoplasms are benign in origin, but some of these histologically benign lesions may be challenging in their management. Although most hepatic hemangiomas can be safely observed until involution is documented, some patients will need treatment due to progressive hepatomegaly, hypothyroidism and/or cardiac failure. Large mesenchymal hamartomas may require extensive hepatic resection and an appropriate surgical plan is critical to obtain good results. For malignant neoplasms such as hepatoblastoma, complete surgical resection is the mainstay of curative therapy. The decision about whether to perform an upfront or delayed resection of a primary liver malignant tumor is based on many considerations, including the ease of resection, surgical expertise, tumor histology and stage, and the likely chemosensitivity of the tumor. This article reviews the initial management of the more common hepatic tumors of infancy, focusing on the differential diagnosis and treatment options.

Focal nodular hyperplasia of the liver in children after hematopoietic stem cell transplantation

FNH is a non-malignant neoplasia of the liver rarely described in children. A significant percentage of the pediatric cases have been reported in patients with a history of malignant disease treated with chemo-radiation therapy and in children who were given HSCT. Little is known about the pathogenesis of FNH in transplanted children, but many risk factors linked to the HSCT procedure have been hypothesized. The detection of hepatic nodules, particularly in children who underwent HSCT for a previous malignancy, always raises a diagnostic dilemma. To help the physicians in the diagnostic management of this rare entity, we have retrospectively evaluated a series of transplanted children diagnosed with FNH in our Center over the last 15 yr. In this period, we found 10 new diagnoses of FNH. The diagnostic work-up included CEUS, abdominal CT, and MRI. A liver biopsy was performed in two patients. The median FUP time after diagnosing FNH was 3.8 yr, with an abdominal US and no malignant transformation were observed. Possible risk factors and indications for the management of FNH in transplanted children are reported and discussed in a comprehensive review of the literature.

Hepatic focal nodular hyperplasia in children: Imaging features on multi-slice computed tomography

AIM: To retrospectively analyze the imaging features of hepatic focal nodular hyperplasia (FNH) in children on dynamic contrast-enhanced multi-slice computed tomography (MSCT) and computed tomography angiography (CTA) images.

METHODS: From September 1999 to April 2012, a total of 218 cases of hepatic FNH were confirmed by either surgical resection or biopsy in the Sun Yat-sen Memorial Hospital of Sun Yat-sen University and the Cancer center of Sun Yat-sen University, including 12 cases (5.5%) of FNH in children (age ≤ 18 years old). All the 12 pediatric patients underwent MSCT. We retrospectively analyzed the imaging features of FNH lesions, including the number, location, size, margin, density of FNH demonstrated on pre-contrast and contrast-enhanced computed tomography (CT) scanning, central scar, fibrous septa, pseudocapsule, the morphology of the feeding arteries and the presence of draining vessels (portal vein or hepatic vein).

RESULTS: All the 12 pediatric cases of FNH had solitary lesion. The maximum diameter of the lesions was 4.0-12.9 cm, with an average diameter of 5.5 ± 2.5 cm. The majority of the FNH lesions (10/12, 83.3%) had well-defined margins. Central scar (10/12, 83.3%) and fibrous septa (11/12, 91.7%) were commonly found in children with FNH. Central scar was either isodense (n = 7) or hypodense (n = 3) on pre-contrast CT images and showed progressive enhancement in 8 cases in the equilibrium phase. Fibrous septa were linear hypodense areas in the arterial phase and isodense in the portal and equilibrium phases. Pseudocapsule was very rare (1/12, 8.3%) in pediatric FNH. With the exception of central scars and fibrous septa within the lesions, all 12 cases of pediatric FNH were homogenously enhanced on the contrast-enhanced CT images, significantly hyperdense in the arterial phase (12/12, 100.0%), and isodense in the portal venous phase (7/12, 58.3%) and equilibrium phase (11/12, 91.7%). Central feeding arteries inside the tumors were observed on CTA images for all 12 cases of FNH, whereas no neovascularization of malignant tumors was noted. In 9 cases (75.0%), there was a spoke-wheel shaped centrifugal blood supply inside the tumors. The draining hepatic vein was detected in 8 cases of pediatric FNH. However, the draining vessels in the other 4 cases could not be detected. No associated hepatic adenoma or hemangioma was observed in the livers of the 12 pediatric cases.

CONCLUSION: The characteristic imaging appearances of MSCT and CTA may reflect the pathological and hemodynamic features of pediatric FNH. Dynamic multi-phase MSCT and CTA imaging is an effective method for diagnosing FNH in children.

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.

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.