* Hospital Mater Dei, Belo Horizonte, MG, Brazil ** Tennessee Women"s Care, Nashville, TN

Introduction: Intraabdominal calcifications are a common finding during fetal scan. Most of them are not associated with additional risk for the fetus or neonate. Fetal hepatic calcifications are punctate hyperechogenicities areas that can be visualize within the hepatic parenchyma, inside the vessels or in the peritoneal surface. Detection of such lesions should prompt a detailed survey for additional findings and a review of the maternal history. In some cases, fetal karyotyping may be indicated (1).

Incidence: Hepatic calcifications are a common finding with an estimated incidence of 5.7-10:10,000(2,3). They are more commonly diagnosed during prenatal scans than in the newborn. Hawass et al, in 1990, reported hepatic calcifications in 33 of 1500 spontaneously aborted fetuses (4).

Classification: The hepatic calcifications can be classified in three categories:

• Peritoneal: the calcifications are located in the surface of the liver. Meconium peritonitis is the most common etiology.
• Parenchymal: The calcifications can be seen in the liver parenchyma. It occurs due to infections or tumors. The tumors can be primary of the liver or metastatic. (hemangioendotheliomas, hamartomas or hepatoblastomas). The infections related to liver calcifications are mainly the TORCH infections (especially cytomegalovirus and varicella).
• Vascular: can be due to emboli from the portal or hepatic veins or ischemic necrosis secondary to vascular insufficiency.

Etiology: Various etiologies have been reported for the hepatic calcifications. Fetal infections, vascular etiology and meconium peritonitis are the more frequent etiologies described (2,4).

Ultrasound findings: In utero diagnosis can often be achieved with careful evaluation of calcifications and additional findings. Calcifications are typically seen as one or more echogenic areas within the liver. Occasionally, multiple calcifications can be seen, and these are more likely to be associated with underlying fetal infection or aneuploidy if any associated anomaly were detected (1).  Ascites could also be seen and they are related to TORCH infections. The visualization of punctuate echogenic foci along the course of the diaphragm are more suggestive of meconium peritonitis. This finding could also be seen associated with a large meconium pseudocyst with a fluid debris level. In cases of calcifications due to emboli from the portal or hepatic veins, isolated subcapsular calcifications may be visualized.

Case report 1: Note the parenchymal calcification.

Case report 2: Note the large hepatic calcification

Case report 3: Note the hepatic calcification close to the surface of the liver

Case report 4: Another case of parenchymal calcification

Differential diagnosis: The differential diagnosis can be divided in two main groups:

• Peritoneal calcifications: The peritoneal hepatic calcifications might be differentiated from the meconium peritonitis and hydrometrocolpos rupture. Meconium peritonitis is a chemical peritonitis resulting from intrauterine bowel perforation. It can be identified as a group of calcifications with a peritoneal distribution. This occurs at shortly after the rupture. Later the fibrotic reaction will embed all the calcifications into a meconial cyst. Other sonographic findings can also be seen in fetuses with meconium peritonitis. These include polyhydramnios, dilatated loops of bowel, fetal ascites, echogenic ascites with mass effect on organs, inguinal hernia and meconium pseudocyst. The prognosis is variable and depends on associated abnormalities (5).
  
• Parenchymal calcifications: The differential diagnosis includes primary and metastatic tumors. The primary tumors include the hemangioma, hemangioendothelioma, hamartoma, and teratoma.  The most common metastatic tumor is the neuroblastoma most commonly originated in the adrenal gland

Associated anomalies: The association between hepatic calcifications and chromosomal anomalies are unlikely when the hepatic calcifications are an isolated finding. Koopman and Wladimiroff reported seven cases of intrahepatic echogenic foci; two with chromosomal anomalies and both of them showed major ultrasound abnormalities (6). Bronshtein and Blazer reported 14 cases of hepatic calcifications, three (21%) had associated severe malformations; two with trisomy 18 and one with skeletal dysplasia and hydronephrosis (7). In another similar study, Simchen et al. evaluated 61 fetuses with hepatic calcifications; ten patients (1.5%) had abnormal karyotype and all of these showed additional anomalies. All 22 cases of isolated hepatic calcification had a normal outcome (8).

Management: The management depends of the size, location and distribution of the calcifications. Screening test for fetal infections should be performed, including toxoplasmosis, rubella, syphilis and herpes simplex. The recommendations for serial ultrasound examinations are controversial. Follow-up scans may be required to evaluate the stability or the regression of the lesions. A careful search for associated anomalies should be performed. In selected patients, in cases in which additional findings are present, an amniocentesis should be performed for fetal karyotype or to obtain samples for specific infection tests (1,2).

Prognosis: The prognosis is generally good when one or two hepatic hyperechogenicities are diagnosed (3,5). However, when multiple calcifications are identified, the association with chromosomal anomalies may be present (5). In this case, the outcome is poor, accordingly to the extension of the abnormalities. Ascites is a sign of a poor outcome. The long-term outcome depends on the underlying causes.

References:

1. McNamara A, Levine D. Intraabdominal fetal echogenic masses: a practical guide to diagnosis and management. Radiographics 2005;25:633-645
2. Simchem MJ, Toi A, Bona M, Alkazaleh F, Ryan G, Chitayat D. Fetal hepatic calcifications: prenatal diagnosis and outcome. Am J Obstet Gynecol 2002;187:1617-22
3. Nyberg DA, MacGahan JP, Pretorious DH, Pilu G, 2003, Diagnostic Imaging of Fetal Anomalies.
4. Hawass ND, El Badawi MG, Fatani JA, Al-Meshari A, Makanjoula D, Edress YB. Foetal hepatic calcification. Pediatr Radiol 1990;20:528-35.
5. Fleischer AC, Manning FA, Jeanty P, Romero R, 2001, sixth edition, Sonography in obstetrics and gynecology.
6. Koopman E, Wladimiroff JW. Fetal intrahepatic hyperechogenic foci: prenatal ultrasound diagnosis and outcome. Prenat Diag 1988;18(8):569-572
7. Bronshtein M, Blazer S. Prenatal diagnosis of liver calcifications. Obstet Gynecol 1995;86(5):739-743
8. Sinchem MJ, Bona M, Toi A et al. Fetal hepatic calcifications: prenatal diagnosis and outcome. Am J Obstet Gynecol 2001;185(6):s238