Focal nodular hyperplasia of the liver after intensive treatment for pediatric cancer: is hematopoietic stem cell transplantation a risk factor?

Superb Microvascular Imaging in Pediatric Focal Nodular Hyperplasia

OBJECTIVE

To investigate superb microvascular imaging (SMI), a novel Doppler ultrasound technique that can visualize low-velocity microvascular flow, for assessing pediatric focal nodular hyperplasia (FNH).

PATIENTS AND METHODS

Nine FNH lesions in 6 patients were enrolled. On SMI and color Doppler imaging (CDI), intralesional vascularity was assessed visually and categorized as typical spoke-wheel pattern (central vessel radiating from the center to the periphery), multifocal spoke-wheel pattern, and nonspecific pattern. We compared the vascular features of the lesions between SMI and CDI and evaluated vascular patterns according to lesion size.

RESULTS

In terms of vascularity pattern, the typical spoke-wheel pattern of FNH was noted more frequently on SMI (67%) than on CDI (11%; P < 0.05). In addition, a multifocal spoke-wheel pattern was noted in all remaining lesions (33%) on SMI. On the contrary, a nonspecific vascular pattern was detected in the majority (78%) of CDI. Regarding the lesion size and vascularity on SMI, the typical spoke-wheel pattern was seen more frequently in the small FNH group than in the large FNH group. The intralesional vascular signal was detected more frequently on SMI (100%) than on CDI (89%).

CONCLUSION

SMI is feasible in evaluating FNH in children and has a greater ability to demonstrate the spoke-wheel pattern than CDI.

Late effects in survivors of high-risk neuroblastoma following stem cell transplant with and without total body irradiation

BACKGROUND

Neuroblastoma is the most common extracranial solid tumor in children. Those with high-risk disease are treated with multimodal therapy, including high-dose chemotherapy, stem cell transplant, radiation, and immunotherapy that have led to multiple long-term complications in survivors. In the late 1990s, consolidation therapy involved myeloablative conditioning including total body irradiation (TBI) with autologous stem cell rescue. Recognizing the significant long-term toxicities of exposure to TBI, more contemporary treatment protocols have removed this from conditioning regimens. This study examines an expanded cohort of 48 high-risk neuroblastoma patients to identify differences in the late effect profiles for those treated with TBI and those treated without TBI.

PROCEDURE

Data on the study cohort were collected from clinic charts, provider documentation in the electronic medical record of visits to survivorship clinic, including all subspecialists, and ancillary reports of laboratory and diagnostic tests done as part of risk-based screening at each visit.

RESULTS

All 48 survivors of BMT for high-risk neuroblastoma had numerous late effects of therapy, with 73% having between five and 10 late effects. TBI impacted some late effects significantly, including growth hormone deficiency (GHD), bone outcomes, and cataracts.

CONCLUSION

Although high-risk neuroblastoma survivors treated with TBI have significant late effects, those treated without TBI also continue to have significant morbidity related to high-dose chemotherapy and local radiation. A multidisciplinary care team assists in providing comprehensive care to those survivors who are at highest risk for significant late effects.

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.

Gd-EOB-DTPA MRI for focal nodular hyperplasia-like lesions in pediatric cancer survivors

OBJECTIVES

To investigate the hepatobiliary enhancement patterns of gadoxetic acid (Gd-EOB-DTPA) MRI and the temporal evolution of focal nodular hyperplasia (FNH)-like lesions in pediatric cancer survivors.

METHODS

We retrospectively included pediatric cancer survivors who had new liver lesions detected during surveillance imaging and who were diagnosed with FNH-like lesions by Gd-EOB-DTPA MRI without the aid of a hepatobiliary phase. The hepatobiliary enhancement patterns of FNH-like lesions were categorized as homogeneous hyperintense/isointense, heterogeneous hyperintense, and ring-like enhancement. Temporal changes in the FNH-like lesions were evaluated by follow-up Gd-EOB-DTPA MRI. Statistical analyses included one-way analysis of variance and Spearman's rank correlation test.

RESULTS

A total of 132 radiologically diagnosed FNH-like lesions in 18 patients showed the three different hepatobiliary enhancement patterns: homogeneous hyperintense/isointense (n = 65, 49%), heterogeneous hyperintense (n = 24, 18%), and ring-like enhancement (n = 43, 33%). A weak positive correlation was found between the lesion size and the hepatobiliary enhancement pattern (p = 0.015). Follow-up MRI showed alterations in the size and number of 55 FNHs in 8 patients, including stable size (n = 15, 27%), increased size (n = 17, 31%), decreased size (n = 11, 20%), disappearance (n = 12, 22%), and 74 new lesions (5 patients, 63%).

CONCLUSIONS

FNH-like lesions in pediatric cancer survivors showed three different hepatobiliary enhancement patterns and various temporal changes. Recognition of the radiological characteristics of FNH-like lesions may avoid unnecessary invasive procedures and reduce patients/parents' anxiety.

KEY POINTS

• FNH-like lesions in pediatric cancer survivors showed three different hepatobiliary enhancement patterns. The most common was homogeneous hyperintense/isointense, followed by heterogeneous hyperintense, and ring-like enhancement. • FNH-like lesions in pediatric cancer survivors can show various temporal changes during follow-up.

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.

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 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.

Benign hepatocellular tumors in children: focal nodular hyperplasia and hepatocellular adenoma

Benign liver tumors are very rare in children. Most focal nodular hyperplasia (FNH) remain sporadic, but predisposing factors exist, as follows: long-term cancer survivor (with an increasing incidence), portal deprivation in congenital or surgical portosystemic shunt. The aspect is atypical on imaging in two-thirds of cases. Biopsy of the tumor and the nontumoral liver is then required. Surgical resection will be discussed in the case of large tumors with or without symptoms. In the case of associated vascular disorder with portal deprivation, restoration of the portal flow will be discussed in the hope of seeing the involution of FNH. HepatoCellular Adenoma (HCA) is frequently associated with predisposing factors such as GSD type I and III, Fanconi anemia especially if androgen therapy is administered, CPSS, and SPSS. Adenomatosis has been reported in germline mutation of HNF1- α . Management will depend on the presence of a predisposing factor and may include metabolic control, androgen therapy withdrawn, or closure of the shunt when appropriate. Surgery is usually performed on large lesions. In the case of adenomatosis or multiple lesions, surgery will be adapted. Close followup is required in all cases.

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.

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.