Several reports have dealt with the prenatal diagnosis of fetal cranial masses by ultrasound exami-Recently, Sabbagha et a15 have suggested that, in cases of cranial masses in which a skull defect that points unequivocally to a cephalocele is not ultrasonically visible, the thickness of the outer margin and the internal characteristics of the mass itself can be used for differential diagnosis. In two instances, ultrasonic diagnosis of meningoencephalocele was not confirmed by pathological examination, which revealed a cystic hygroma of the neck in one case6 and a "nuchal bleb" in the other.7 This underlines the difficulties in the differential diagnosis of fetal cranial masses.
CASE REPORTS
Case 1 C.R., a 30-yr-old pregnant woman in week 32 of her third pregnancy, after two miscarriages, underwent a routine ultrasound examination. This revealed a microcephalic fetus (head circumference, 24 cm; abdominal circumference, 27 ~m ) . ~, '
A cystic mass with a median septum was observed on the back of the fetal neck (Fig 1). The ultrasonic presumptive diagnosis was cephalocele. Amniotic alpha fetoprotein (AFP) was above 3 SD.1Β°
One week later, a male infant weighing 1980 g was delivered. The baby died 24 hr after birth, and the pathological examination showed occipitoparietal encephalocele associated with agenesis of the corpus callosum.