*Fetal-maternal medicine unit, Department of Obstetric and Gynecology, Rajavithi hospital, Bangkok,Thailand.
** Inner Vision Women's Ultrasound, Nashville, Tennessee, USA.

Images 7,8: Doppler imaging of the tumor shows it's profound vascularization.

Hepatoblastoma

Hepatoblastoma is the most common hepatic malignancy among neonates and in childhood. The most common initial finding is an elevation of α-fetoprotein. Unfortunately, this includes only half of the prenatally diagnosed cases. Other initial finding is a hepatic or abdominal mass detected on the ultrasound [1,8]. There are four main histological types: 1) fetal and 2) embryonal 3) fetal with embryonal and 4) fetal with embryonal and mesenchymal component [1,3].

Prevalence: very rare

Ultrasound findings

Hepatoblastomas are well-defined, lobulated, echogenic lesions, which may have internal structure like a spoked-wheel appearance. Most common site is the right lobe of the liver.

Differential diagnosis

Includes metastatic neuroblastoma and benign causes such as hemangioma, mesenchymal hamartoma, adenoma, and focal nodular hyperplasia [1].

Treatment and prognosis

Because of the rarity of this disease, the treatment protocols vary depending on the clinical findings. However, the treatment modalities include: primary chemotherapy and surgical resection, or chemotherapy alone [9]. If untreated it is usually fatal within 2 years.

Images 9,10: Transverse view of the fetal abdomen showing a hepatoblastoma. Note the well-defined, encapsulated lesion.

Images 11,12: Doppler imaging showing the vascularization of the tumor mass.

Classification of fetal and neonatal hepatic tumors and tumorlike conditions [1,13]:

• Infantile hemangioma: Focal; Multifocal (Hemangioendothelioma type 1, Hemangioendothelioma type 2)

• Mesenchymal hamartoma

• Solitary unilocular cyst

• Adenoma

• Focal nodular hyperlasia

• Hepatoblastoma: Epithelial (Fetal, Embryonal); Mixed: epithelial and mesenchymal; Anaplastic

• Hepatocellular carcinoma

• Germ cell tumors: Teratoma; Yolk sac tumor; Choriocarcinoma

• Rhabdoid tumor

• Hepatic sarcoma: Undifferentiated (embryonal) sarcoma; Rhabdomyosarcoma

• Metastatic neoplasms: Neuroblastoma; Leukemia; Renal tumors; Yolk sac tumor; Rhabdoid tumor; Choriocarcinoma

References:

1.Isaacs H, Jr. Fetal and neonatal hepatic tumors. J Pediatr Surg. 2007 Nov;42(11):1797-803.

2.Mahony R, McParland P. Approaches to the management of antenatally diagnosed congenital tumours. Pediatr Radiol. 2009 Nov;39(11):1173-8.

3.Callen PW. Ultrasonography in obstetrics and gynecology. 5th ed. Philadelphia: Saunders Elsevier; 2008.

4.Sari N, Yalcin B, Akyuz C, Haliloglu M, Buyukpamukcu M. Infantile hepatic hemangioendothelioma with elevated serum alpha-fetoprotein. Pediatr Hematol Oncol. 2006 Dec;23(8):639-47.

5.Siddiqui MA, McKenna BJ. Hepatic mesenchymal hamartoma: a short review. Arch Pathol Lab Med. 2006 Oct;130(10):1567-9.

6.Stringer MD, Alizai NK. Mesenchymal hamartoma of the liver: a systematic review. J Pediatr Surg. 2005 Nov;40(11):1681-90.

7.Cornette J, Festen S, van den Hoonaard TL, Steegers EA. Mesenchymal hamartoma of the liver: a benign tumor with deceptive prognosis in the perinatal period. Case report and review of the literature. Fetal Diagn Ther. 2009;25(2):196-202.

8.Shih JC, Tsao PN, Huang SF, Yen BL, Lin JH, Lee CN, et al. Antenatal diagnosis of congenital hepatoblastoma in utero. Ultrasound Obstet Gynecol. 2000 Jul;16(1):94-7.

9.Davies JQ, de la Hall PM, Kaschula RO, Sinclair-Smith CC, Hartley P, Rode H, et al. Hepatoblastoma--evolution of management and outcome and significance of histology of the resected tumor. A 31-year experience with 40 cases. J Pediatr Surg. 2004 Sep;39(9):1321-7.

10. Isaacs Jr H. Liver tumors. In: Isaacs Jr H, editor. Tumors of the fetus and infant: an atlas. New York (NY): Springer-Verlag; 2002. p. 303-36.