FETAL HEPATIC HEMANGIOENDOTHELIOMA

Case Report by: Martin Necas, RDMS, RVT and Karen Robertson, DMU
WAIKATO HOSPITAL Dept. of Ultrasound, Hamilton, New Zealand

Introduction
Benign hemangioendothelioma is a rare liver neoplasm, however it represents the most common vascular tumor of the liver in the neonate.(1) While small hemangioendotheliomas can be asymptomatic, larger tumors act as arterio-venous shunts resulting in high-output cardiac failure. The neonatal clinical presentation of hemangioendothelioma includes: 1) gross liver enlargement, 2) high-output cardiac failure, and 3) associated hemangiomas in other organs including skin (hemangiomatosis).(2) Other complications include consumptive coagulopathy, hemolytic anemia, tumor rupture, and problematic surgical intervention. Although the reported mortality rate of hemangioendotheliomas is traditionally very high (upward of 70%), recent studies report an improved long-term prognosis. The treatment options include conservative management, medication (steroids and interferons), radiological options (irradiation and selective embolization), and surgical intervention (ligations of feeding vessels, tumor excision).(1-3) Hemangioendotheliomas have been recognized on obstetric ultrasound.(4,5) Neonatal CT, repeat sonography, MRI imaging, and arteriography have all been utilized to visualize the tumor and assess it's size, location, and the anatomy of arterio-venous malformation (AVM) in the neonate. The antenatal ultrasound features of hemangioendothelioma include: liver mass (heterogeneous, hypoechoic, complex with anechoic spaces, and hyperechoic), consequent liver enlargement, prominent vasculature, cardiomegaly, and possible hydrops (serous effusions and body edema). (2,4-8) Color and pulsed Doppler interrogation can also be particularly useful in identifying an AVM. (5,8,9)

History
31 year old primigravida presented for a routine anatomy scan at 21 weeks gestational age (GA) to an outpatient ultrasound department. Heterogeneous (primarily anechoic) lesion was noted in the right lobe of the liver measuring approximately 1.5cm in diameter. No other fetal anatomic abnormalities were detected. The patient was directed to our tertiary hospital for specialist referral and follow-up ultrasound at 30 weeks.

Antenatal Ultrasound Findings
Scan at 30 weeks again demonstrated this liver lesion (Figure 1). Color and pulsed Doppler interrogation revealed a highly vascular lesion with disturbed pulsatile flow patters (Figures 2-3). An AVM with significant shunting through the lesion was strongly suspected. The fetal heart appeared visibly enlarged (Figure 4), however there were no secondary signs of cardiac failure or fetal hydrops . An interesting finding at 33 weeks was the notable difference in aortic caliber proximal and distal to the major mesenteric arteries: celiac axis and SMA (Figure 5). This finding further supported the hypothesis of significant shunting through the liver, and has been previously documented in infants with liver AVM.(9) Fetal growth appeared greater than expected with the estimated fetal weight above the 95th percentile consistent with a large for gestational age fetus. Although no evidence of serous effusions was detected during the pregnancy, borderline polyhydramnios (AFI=21cm) and increased placental thickness were noted in the late 3rd trimester.

Figure 1: Coronal and Transverse images of the fetal liver demonstrated an anechoic mass (arrowhead).

Figure 2: Color Doppler imaging revealed prominent vascularity of the lesion. (click on image for larger version)

Figure 3: Disturbed Pulsed Doppler signals were obtained.

Figure 4: The heart was enlarged.

Figure 5:
The calibre of the distal aorta (arrow) was notably smaller than the calibre of the proximal aorta (arrowhead).

Birth:

A male fetus was delivered via C-section at 37 weeks GA after a period of decreased fetal movements and "very flat" CTG. (Weight at delivery: 3420 grams Apgar scores: 2 and 5 at 1 and 5 minutes respectively) The baby was bradycardic and edematous (see Figure 10) with poor respiratory effort and clinical signs of congestive heart failure, anemia, and coagulopathy. Renal failure soon developed.

Neonatal Imaging (DAY 2):

Ultrasound demonstrated poorly defined echogenic liver lesions and large vessels in the area (Figure 6). No serous effusions were seen (pericardial, pleural, or ascites). The infant also underwent CT scan which again revealed multiple hemangiomata throughout both lobes of the liver with little identifiable normal parenchyma. The massive AVM was seen in the right lobe(Figure 7). Due to the critical condition of the infant, angiography was not performed prior to surgery.

Figure 6: Neonatal ultrasound demonstrated liver masses. (click on image for larger version)

Figure 7: Massive right liver lobe AVM was seen.
Compare arterial phase (top) and late venous phase (bottom). (click on image for larger version)

Surgical Intervention (DAY 3):

Massive hemangiomatous mass was revealed in the right lobe (Figure 8) and two (smaller) in the left. Multiple feeding vessels were visualized in the region of the celiac axis, SMA, diaphragm, and duodenum. Ligation of the aberrant hepatic blood supply was performed (Figure 9). Peritoneal dialysis catheter was inserted at this time.

Figure 8: Laparotomy revealed a large right lobe liver mass (arrowhead)

Figure 9: Surgical ligation of aberrant vasculature (arrowhead)

Outcome (DAY 3-7)

The baby remained in critical condition (Figure 10) with complications related to cardiac, respiratory and renal failure. He died on day 7.

Figure 10:
The baby remained in critical condition and died on day 7.

Conclusion

Hemangioendothelioma is a rare tumor of the liver which can be visualized on an obstetric sonogram. If large enough, this tumor can act as an AVM and cause serious sequelae in utero and post-natally. The antenatal diagnosis of hemangioendothelioma is based on recognizing the characteristic sonographic warning signs, and the demonstration of an AVM on Color and Pulsed Doppler. This in turn allows the pediatric team to prepare a treatment strategy. Post natal imaging is performed to confirm sonographic findings and map the involved anatomy for future follow-up, or radical surgical intervention.

References

1) Davenport M, Hansen L, Heaton ND, Howard ER: Hemangioendothelioma of the Liver in Infants. J Pediatr Surg 1995 Jan;30(1):44-7.

2) Feldman M, ed., et al: Sleisenger & Fordtran's Gastrointestinal and Liver Disease: Pathophysiology/ Diagnosis/ Management, 6th ed. Philadelphia: WB Saunders, 1998; 1379-80.

3) Samuel M, Spitz L: Infantile Hepatic Hemangioendothelioma: The Role of Surgery. J Pediatr Surg 1995 Oct;30(10):1425-9.

4) Abuhamad AZ, Lewis D, Inati MN, Johnson DR, Copel JA: The use of color flow Doppler in the diagnosis of fetal hepatic hemangioma. J Ultrasound Med 1993;4:223-6.

5) Mejides AA, Adra AA, O'Sullivan MJ, Nicholas MC: Prenatal dianosis and therapy for a fetal hepatic vascular malformation. Obstet Gynecol 1995 May;85(5 pt 2):850-852.

6) Gonen R, Fong K, Chiasson DA: Prenatal Sonographic Diagnosis of Hepatic Hemangioendothelioma with Secondary Nonimmune Hydrops Fetalis. Obstet Gynecol 1989 Mar;73(3 pt 2):485-7.

7) Horgan JG, King DL, Taylor KJW: Sonographic Detection of Prenatal Liver Mass. J Clin Gastroenterol 1984 Jun;6(3):277-80.

8) Paltiel HJ, Patriquin HB, Keller MS, Bobcock DS, Leithier RE: Infanitle hepatic hemangioma: Doppler US. Radiology 1992;182:735-42.

9) Boon LM, Burrows PE, Paltiel HJ, et al: Hepatic Vascular Anomalies in Infancy: A Twenty-seven-year Experience. J Pediatr 1996 Sep;129(3):346-55.