Alobar holoprosencephaly with cebocephaly in a neonate: A rare case report from Northern Tanzania

Abstract

Introduction and importance: Holoprosencephaly is a rare brain malformation consisting of impaired midline cleavage of the embryonic forebrain presenting with variable features of craniofacial dysmorphism. It affects 1 in 10,000 live births occurring more in females than males. We present a case of alobar HPE and aim to raise awareness on the importance of early prenatal detection and counselling.

Case presentation: We present a case of 3200-gram female baby, born by spontaneous vaginal delivery with APGAR scores of 5 and 6 in the first and fifth minute of life respectively. On admission, the baby was lethargic, had central and peripheral cyanosis, hypothermic with temperature of 32.1 °C, respiratory rate of 65 breaths/min, heart rate of 135 beats/min and oxygen saturation of 94% with an oropharyngeal airway and on oxygen support via a face mask. She had microcephaly, hypotelorism, and a small nose with a single imperforate nostril. She was diagnosed to have alobar holoprosencephaly with cebocephaly. A computed tomography scan of the brain revealed a cephalohematoma in the vertex and an intranasal soft tissue density lesion blocking the entrance measuring approximately 10 × 8.5 mm. Absence of the corpus callosum and septum pellucidum with a resulting monoventricle formed from the lateral ventricles, the fusion of the thalami and a sizeable arachnoid cyst involving the left cerebellar hemisphere were evident. She was started on IV antibiotics and IV fluids. Non-invasive airway management was opted for by the ENT team based on the condition of the baby. She succumbed to death 6 days post admission due to severe respiratory failure.

Clinical discussion: The types of HPE are alobar, semi lobar, lobar and interhemispheric variants. Alobar HPE is the most severe form and is incompatible with life. Clinical presentation entails facial dysmorphism with features of hypotelorism, microcephaly and a blind ended nostril. Alobar and semilobar HPE can reliably be diagnosed with ultrasound during the first and second trimesters of pregnancy. Absence of choroid plexus and fused cortex are pathognomonic characteristic on ultrasound and CT scan respectively.

Conclusion: Alobar holoprosencephaly is a rare brain malformation which is incompatible with life. Prenatal ultrasound screening of the foetus brain is essential and reliable in making a diagnosis. Absence of the "butterfly" sign in the foetal brain ultrasonography should raise a high index of suspicion for brain malformation with unfavourable outcome. Legal medical termination of pregnancy may serve as an early intervention.

Keywords: Case report; Cebocephaly; Holoprosencephaly; Proboscis.