Clinically Significant Ascites as an Indication for Resection of Rapidly Involuting Congenital Hepatic Hemangiomas

Abstract

Hepatic hemangiomas are the most common benign liver tumor of infancy and are divided into two main types: rapidly involuting congenital hemangiomas (RICH) and non-involuting congenital hemangiomas (NICH).^1,2 RICH typically involute by 12 months and are often asymptomatic.² Surgical resection is rare. Indications for surgical resection include rupture, rapid growth, consumptive coagulopathy, and abdominal pain.³ Here we present two patients from different institutions who both developed clinically significant ascites as the RICH involuted, prompting surgical resection. This is a new indication for resection that has not been previously described.

Introduction

Hepatic hemangiomas, while rare, are the most common benign liver tumor of infancy representing 14% of all the primary hepatic tumors of childhood. About 30% of hepatic hemangiomas are unifocal congenital hemangiomas and the rest are multifocal or diffuse infantile hemagiomas.¹ In contrast to the more common infantile hemangiomas, congenital hepatic hemangiomas are fully formed at birth. These are of two types: Rapidly involuting congenital hemangiomas (RICH) that undergo an accelerated involution phase completed by 12 to 15 months⁴ and non-involuting congenital hemangiomas (NICH) that maintain the same size indefinitely.²

Often they are clinically silent, and are first seen on routine perinatal ultrasounds performed for other reasons. These vascular lesions can be diagnosed by their appearance on magnetic resonance imaging (MRI) which includes hypointensity on T1 weighted images and hyperintensity on T2 weighted images.⁴ Biopsy is rarely needed and may be contraindicated due to risk of bleeding. Though often asymptomatic, hepatic hemangiomas can also present with signs of anemia, thrombocytopenia, and heart failure.² Indications for surgical resection include spontaneous or traumatic rupture, rapid growth, consumptive coagulopathy, and abdominal pain.³ Here we present two cases of male infants who developed clinically significant ascites as their hepatic hemangiomas started the involution process. Surgical resection was performed with complete resolution of ascites and respiratory compromise.

Case 1

A 32-week Hispanic male was found on routine prenatal ultrasound (US) at 31 weeks gestation to have a 6.9cm left hepatic lobe mass. MRI obtained shortly after birth confirmed a 7cm×5.2 cm left hepatic lobe hemangioma (Figure 1). During the immediate neonatal period, the recommendation was to monitor clinically without surgical intervention. At 2 months of age, he developed respiratory failure secondary to acute abdominal distension. Repeat US showed the hepatic mass to be stable in size without significant shunting, compression of hepatic vessels or portal hypertension, with a large amount of ascites present. Alpha-fetoprotein (AFP) levels were within the normal range for age (2090–4520ng/ml). Further workup, including echocardiogram, renal function tests, and infectious work up failed to reveal a primary etiology for his ascites. The patient underwent multiple paracentesis as well as drain placement, however ascites quickly reaccumulated and he was unable to be weaned from mechanical ventilation.

Figure 1.

Case 1. Abdominal MRI with T2-weighted image. Classically, hepatic hemangiomas appear hypointense on T1 weighted images and hyperintense on T2 weighted images. This hyperintensity on T2 weighted imaging is one of the important features that distinguish hemangiomas from a solid neoplastic liver lesion. Arrow is pointing at lesion, with white hyperintensity seen throughout the mass

Inability to wean from mechanical ventilation in the setting of intractable ascites led to the decision to resect the mass with a left lateral segmentectomy. Pathology was consistent with a RICH, showing small lobules of capillaries surrounded by fibrous tissue, with a central involution component with connective tissue and sparse lobules. Unlike infantile hemangioma (IH), the endothelial cells were negative for glucose transporter-1 protein (GLUT - 1), confirming the diagnosis of RICH.⁵ Post-operatively the baby recovered well and the ascites did not re-accumulate with over 24 months of follow-up.

Case 2

A Hispanic male was born at 35 weeks 5 days via Cesarean section for fetal heart rate decelerations and polyhydramnios. He was found to have a large abdominal mass at birth. He was brought to the Neonatal Intensive Care Unit for respiratory distress attributed to mass effect. Echocardiogram revealed a small ventricular septal defect and a small patent foramen ovale. There was no evidence of portal hypertension on ultrasound. MRI revealed a large, well-circumscribed T1 hypointense, predominantly T2 hyperintense mass originating from the left hepatic lobe measuring 8.9×6×8.8 cm which demonstrated nodular peripheral enhancement consistent with hepatic hemangioma. Repeat MRI 1 month later revealed enlargement of the mass to 8.2×11.2×10.9 cm. He was discharged at 5 weeks. He continued to have serial ultrasounds to monitor the mass which decreased in size, consistent with a RICH, however he developed ascites, which worsened as the mass involuted.

He was admitted at 6 months of age with respiratory distress. Imaging revealed a moderate right pleural effusion in addition to worsening ascites, with the mass now 8.3×6.1×7.3 cm (Figure 2). He underwent thoracentesis and paracentesis with 245 cc drained from his right chest and 240 cc of ascitic fluid. Fluid analysis of the pleural fluid was exudative. Ascitic fluid was not sent for analysis but cultures remained negative. He then underwent RICH resection via a left lateral segmentectomy, with right thoracostomy. Chest tube was removed 3 days after resection, and patient was discharged after an uneventful post-operative course on day 5. Pathology was consistent with RICH, with endothelial cells staining negative for GLUT-1. The ascites and pleural effusion have not reaccumulated over a 12 month follow up and the baby is doing well.

Figure 2.

Case 2. Abdominal MRI with T2-weighted image. Mass at 5 1/2 months of age. Arrow is directed at mass, with white hyperintensity seen centrally.

Discussion

We describe two infant Hispanic males with hepatic RICH based on characteristic imaging and histology as described above. In terms of alternate diagnoses other than RICH, there was no lymphedema to suggest any congenital lymphedema syndromes and neither the ascitic fluid in Case 1 or pleural fluid in Case 2 were chylous.⁶ In both patients, the tumors were negative for Glut-1 (in contrast to infantile hemangiomas), and underwent involution (in contrast to neonatal hemangiomas).^2,4 However, we cannot say that both of these tumors would have completely resolved on their own by one year of age, which would further support the diagnosis of RICH because they were resected before that time point.⁴ These patients were both unusual in having developed symptomatic ascites concurrent with tumor involution. The mechanism for ascites formation during involution could be due to lymphatic obstruction or inflammation caused by involution, however exact mechanism is unknown. Ascitic fluid had inflammatory markers but no evidence of infection.⁴ In both patients, the ascites resolved after complete tumor resection. Clinically significant ascites has not been previously described in the literature as an indication for resection.

While our cases both presented as single lesions, congenital hemangiomas can also present as multifocal or diffuse. Multifocal lesions are hypodense with uniform or centripetal enhancement, and are often asymptomatic. Diffuse lesions present with extensive hepatic involvement and near total replacement of hepatic parenchyma with lesions, resulting in hepatomegaly that can cause circulatory and or respiratory compromise.⁷

Confusing nomenclature still affects the medical literature, and may lead to conflicting recommendations for management since hepatic hemangiomas follow a different clinical course than hemangiomas elsewhere. Congenital and infantile hepatic hemangioma are both benign hepatic tumors. While they share some clinical features, they are histologically different and have different expected natural course. Both entities have a proliferation, stabilization and involution phase. Congenital hemangiomas start to grow in utero and complete the proliferation phase by the time of delivery. Infantile hemangiomas initiate proliferation in the first weeks after birth. Hepatic congenital hemangiomas are Glut-1 negative, mostly unifocal, while hepatic infantile hemangiomas are Glut-1 positive and present as multifocal or diffuse types. Infantile hemangiomas have a stable clinical course, while congenital hemangiomas undergo a rapid involution phase. Congenital hemangiomas may either be rapidly-involuting (RICH) or non-involuting (NICH) in contrast with infantile hemangiomas that will almost always involute (but over a longer period of time). Medical management is most effective during the acute proliferation time, hence congenital hemangiomas are not responsive to it (even though occasionally attempted in complicated cases).^2–5 As a general recommendation, hepatic congenital hemangiomas require only supportive care and close monitoring without medical therapy or surgical resection.⁸

Conclusion

Ascites formation during involution of hepatic RICH can be managed by surgical resection. We suggest adding this to the indications listed previously for surgical resection. Further standardization of diagnostic criteria as well as management are needed for these hepatic tumors since they are unique entities from hemangiomas elsewhere.

Ethics Statement.

Informed consent was obtained prior to the use of the images in this case report.

Abbreviations

RICH

Rapidly Involuting Congenital Hemangioma

NICH

Non-involuting Congenital Hemangioma

US

Ultrasound

MRI

Magnetic Resonance Imaging

AFP

Alpha-fetoprotein

GLUT-1

Glucose Transporter-1

IH

Infantile Hemagioma