Unusual presentation of a case of fetal hepatic mass: a case report.

Background: Giant hepatic hemangiomas are rare and can cause serious complications that contribute to a high risk of perinatal mortality. The purpose of this article is to review the prenatal imaging features, treatment, pathology, and prognosis of an atypical fetal giant hepatic hemangioma and to discuss the differential diagnosis of fetal hepatic masses.

Case Presentation: A gravida 9, para 0 woman at 32 gestational weeks came to our institution for prenatal ultrasound diagnosis. A complex, heterogeneous hepatic mass measuring 5.2 × 4.1 × 3.7 cm was discovered in the fetus using conventional two-dimensional ultrasound. The mass was solid and had both a high peak systolic velocity (PSV) of the feeding artery and intratumoral venous flow. Fetal magnetic resonance imaging (MRI) revealed a clear, hypointense T1-W and hyperintense T2-W solid hepatic mass. Prenatal diagnosis was very difficult due to the overlap of benign and malignant imaging features on prenatal ultrasound and MRI. Even postnatally, neither contrast-enhanced MRI nor contrast-enhanced computed tomography (CT) was useful in accurately diagnosing this hepatic mass. Due to persistently elevated Alpha-fetoprotein (AFP), a laparotomy was performed. Histopathological examination of the mass showed atypical features such as hepatic sinus dilation, hyperemia, and hepatic chordal hyperplasia. The patient was ultimately diagnosed with a giant hemangioma, and the prognosis was satisfactory.

Conclusions: When a hepatic vascular mass is found in a third trimester fetus a hemangioma should be considered as a possible diagnosis. However, prenatal diagnosis of fetal hepatic hemangiomas can be challenging due to atypical histopathological findings. Imaging and histopathological assays can provide useful information for the diagnosis and treatment of fetal hepatic masses.