Focal Nodular Hyperplasia in Children Following Treatment of Hemato-Oncologic Diseases

Management of benign liver tumors

Benign liver tumors in children are far less frequent than their malignant counterparts. Recently, there have been advances of diagnostic procedures and novel treatments with improved classification as a result. While malignant pediatric liver tumors have been comprehensively addressed by multicenter international tumor trials, benign tumors have more usually relied upon individualised workup and treatment. Due to the rarity and heterogeneity of these different entities, large studies are lacking. In this article the authors highlight the spectrum of benign liver tumors with special focus on specific clinical features, pathology, and treatment.

Focal nodular hyperplasia in children: an institutional experience with review of the literature

BACKGROUND

Focal nodular hyperplasia (FNH) is uncommonly diagnosed in pediatric patients and may be difficult to distinguish from a malignancy. We present a review of all children with a tissue diagnosis of FNH at our institution, describe the diagnostic modalities, and provide recommendations for diagnosis and follow-up based on our experience and review of the literature.

METHODS

A retrospective review of children <18years of age diagnosed with FNH at a single institution was performed from 2000 to 2013.

RESULTS

Twelve patients were identified with a tissue diagnosis of FNH. Two patients required surgical resection of their lesion owing to concern for malignancy. Ten patients were managed expectantly with imaging surveillance after biopsy confirmed a diagnosis of FNH. All patients who underwent MRI had very typical findings including hypointensity on T1 weighted sequences, hyperintensity on T2, and homogenous uptake of contrast on the arterial phase. On follow-up all patients had either a stable lesion or reduction in size.

CONCLUSIONS

Focal nodular hyperplasia presents typically in children with liver disease, have undergone chemotherapy, and adolescent females. Young children, particularly <5years of age, without underlying liver disease or history of chemotherapy can pose a diagnostic dilemma. In this unique subgroup of children with FNH, MRI and/or needle biopsy should be adequate diagnostic modalities for these lesions.

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 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.

Hypervascular hepatic nodules in childhood cancer survivors: clinical and imaging features

AIM

The aim was to review the clinical and imaging features of hypervascular hepatic nodule (HHN) in childhood cancer survivors.

MATERIALS AND METHODS

We retrospectively reviewed 11 pediatric patients (female:male, 7:4; age range, 4.0-12.3 years) who had HHNs detected by surveillance computed tomography (CT) after treatment of a malignant solid tumor and subsequently followed by serial imaging without evidence of recurrent malignancy. The lesions were analyzed in terms of number, size, location, CT and ultrasonographic (US) features, and changes in background liver. In addition, clinical features were investigated along with follow-up changes of HHNs by imaging monitoring.

RESULTS

Time between initial diagnosis of malignancy and HHN occurrence ranged from 3.2 to 8.5 years (median, 5.8 years). Ten patients had received high-dose chemotherapy and autologous stem cell transplantation for advanced neuroblastoma. A total of 22 nodules were detected, being multiple in six patients and measuring 0.5-3.0 cm in size. At sequential postcontrast CT, nodules demonstrated moderate to strong enhancement during the earlier phase and were isoattenuated during the later phase. On US, they appeared as hypo- or isoechoic lesions. During follow-up, 11 nodules (50%) regressed, 6 (27%) progressed, and 5 (23%) remained stable. Additional HHNs were noted in four patients during follow-up.

CONCLUSION

Childhood cancer survivors are at risk of developing HHNs, which are often multiple and small, years after completing chemotherapy. They are nonaggressive and tend to have a benign course, making conservative management reasonable.

Focal nodular hyperplasia in children, adolescents, and young adults

BACKGROUND

Focal nodular hyperplasia (FNH) is a benign hepatic tumor that is rare in children. In order to understand whether there are differences in the etiology or appearance of FNH in children, we analyzed the clinical information and imaging of pathologically proven cases.

MATERIALS AND METHODS

A pathology database was used to identify all cases of FNH diagnosed at our institution. Each patient's imaging was evaluated for the characteristics of FNH lesions. Clinical information was obtained on each patient.

RESULTS

Thirteen patients with FNH were identified (7 male/6 female, mean age 14.3 years, range 1-27 years). Seven patients (5 male/2 female) had a remote history of childhood malignancy. The time interval between the diagnoses of malignancy and FNH ranged from 9 to 27 years (mean 14.4 years). On imaging, all seven cancer survivors had multiple liver lesions. In the remaining six patients (2 male/4 female), there was no history of malignancy and all but one of these patients had a solitary FNH.

CONCLUSION

Half of the patients with FNH in this study were long-term cancer survivors and each of these patients had multiple masses. Recognizing the features of FNH will aid in diagnosis and appropriate management.

Focal nodular hyperplasia in children: clinical features and current management practice

BACKGROUND

Although nonoperative management is an accepted practice for most adults with focal nodular hyperplasia (FNH), questions remain about the safety and feasibility of this strategy in children. Our aim was to review the clinical features of children with FNH and determine current management patterns.

METHODS

We reviewed records of all children and adolescents with FNH managed at our institution from 1999 to 2009 and performed a MEDLINE search to identify all published cases of FNH in the pediatric population.

RESULTS

A total of 172 patients with FNH were identified, including 11 at our institution. The median age at diagnosis was 8.7 years and 66% were female. Median tumor size was 6 cm, and 25% had multiple lesions. Thirty-six percent were symptomatic at presentation. Twenty-four percent had a history of malignancy. Management included resection (61%), biopsy followed by observation (21%), and observation alone (18%). Indications for resection included symptoms (48%), inability to rule out malignancy (24%), tumor growth (15%), and biopsy-proven concurrent malignancy (9%).

CONCLUSIONS

Although FNH is a benign lesion that is typically managed nonoperatively in adults, most children with FNH currently undergo resection because of symptoms, increasing size, or inability to confidently rule out malignancy.

Focal nodular hyperplasia after orthotopic liver transplantation

Focal nodular hyperplasia (FNH) has been well characterized in native livers, but to our knowledge, no cases of FNH have been described in liver allografts. We review the clinicopathological features of 6 FNHs identified in 4 patients after orthotopic liver transplantation. There were 3 male patients and 1 female patient ranging in age from 2 to 63 years. The time from transplant to a diagnosis of FNH ranged from 15 to 118 months. Two patients presented with an incidental solitary liver nodule. One patient presented with 2 liver nodules, and the other patient initially presented with 1 liver nodule and was found to have another nodule at autopsy 6 years later. Two FNHs were seen as an incidental finding at autopsy, and the other 4 were initially identified on ultrasound. Follow-up magnetic resonance imaging and computed tomography scans revealed features atypical for FNH and suspicious for hepatocellular carcinoma. The initial diagnosis of FNH was made by needle core biopsy in 3 cases and at autopsy in 2 cases. The lesions ranged in size from 1.7 to 6.9 cm. Three patients had conditions associated with altered hepatic vascular perfusion; 2 patients had portal vein thrombosis, and 1 had a partial allograft from a living donor. In conclusion, FNH can present as a hepatic nodule after orthotopic liver transplantation and should not be confused with hepatocellular carcinoma. Because of altered hepatic circulation in the posttransplant liver, a diagnosis of FNH would not be unexpected. FNH should be considered in the differential diagnosis of hepatic nodules within the posttransplant liver, especially in patients with known hepatic vascular perfusion abnormalities.

Focal nodular hyperplasia of the liver in longterm survivors of neuroblastoma: how much diagnostic imaging is necessary?

OBJECTIVES

Focal nodular hyperplasia of the liver is a tumor-like lesion, uncommon in children, but it has recently been more frequently observed in children treated for malignant diseases, especially neuroblastoma. The aetiology is unclear, the pathogenesis remains controversial. Focal nodular hyperplasia of the liver is suspected to be a sequela of tumor therapy.

METHODS

Besides the clinical data we evaluated the imaging modalities needed to diagnose focal nodular hyperplasia of the liver in children with neuroblastoma who have been followed in our institution for more than 5 years.

RESULTS

Out of 60 children six developed focal nodular hyperplasia at a median time of 10.5 years after diagnosis of neuroblastoma and 9.4 years after the end of treatment. The diagnosis of focal nodular hyperplasia was based on imaging criteria which are variable in ultrasonography and specific in MRI. Only one child underwent surgical biopsies to rule out liver metastases.

CONCLUSIONS

Longterm survivors of neuroblastoma are at risk of developing focal nodular hyperplasia, especially if they underwent toxic chemotherapy and/or radiotherapy to the liver during initial treatment. The recommended diagnostic imaging tools are ultrasonography for detecting liver lesions and MRI for confirming and characterizing these lesions as focal nodular hyperplasia.