PP-09 Alobar holoprosencephaly with cebocephaly a rare case report

Objective

In the embryological period, the neural tube consists of three structures: forebrain, midbrain and hindbrain.[1] Holoprosencephaly is a term that refers to a wide variety of cranial malformations characterized by a problem in dividing the forebrain into two separate hemispheres. Depending on the location and severity of the pathology, it can be classically in three types as alobar, semilobar, and lobar, and additionally, it may be the middle interhemispheric variant of holoprosencephaly, which has been described recently.[2]  The division problem in alobar, semilobar and lobar holoprosencephaly is in the basal forebrain. The middle interhemispheric variant, on the other hand, occurs from the fusion of the hemispheres in the parietal and posterior frontal lobes .[3,4] Approximately 80% of affected fetuses progress with craniofacial anomalies. These fetuses may present with cebocephaly, cyclopia, proboscis, microcephaly, ocular hypotelorism, single nostril, cleft palate and lip, or various combinations of these.[2,5] While the frequency of holoprosencephaly is 1 in 250 in abortion materials, its frequency in live births is expressed as 0.6-1 in 10000.[5] Our aim with this case report was to present a case of cebocephaly and alobar holoprosencephaly, which was detected in a patient who applied to our clinic for control in the second trimester of pregnancy, together with its clinical management and findings.

Methods

Computer-based and ultrasonography records of a case with cebocephaly and holoprosencephaly who applied to the Prof. Dr. Cemil Taşçıoğlu City Hospital Perinatology outpatient clinic at the 20th week of pregnancy were scanned retrospectively from the hospital system and the history of the ultrasonography device. Fetal ultrasonography examination was performed using Mindray Resona 7 device and its 1.2-6 MHz convex abdominal probe. Ultrasonography findings and patient history were noted.

Case

An 18-year-old primagravid patient who was pregnant at 20 weeks and 1 day according to her last menstrual period without follow-up applied to us for control. In her anamnesis, she had no additional features other than being cousins with her husband. He hadn’t done the screening tests. In the ultrasonography performed on the patient, fetal biometry was compatible with 20 weeks, normal according to the amniotic fluid week, and the placenta had a natural appearance in the posterior region. Both lateral ventricles merged in a crescent shape and were observed in a monoventricular appearance (Figure 1). Fusion was detected in thalamic nuclei. Cranial examination was evaluated as alobar holoprosencephaly. Fetal facial examination revealed a single nostril in the nose and was evaluated as cebocephaly (Figure 2). Interocular distance was 9.6 mm and binocular distance was measured as 23.3 mm. In addition to these, echogenic bowel and double-bubble appearance were observed. There was polydactyly in the hands. The patient and her husband were informed about the existing anomalies and possible prognosis, and amniocentesis was recommended. The family accepted the amniocentesis procedure. No numerical or gross structural chromosomal abnormality was observed as a result of the amniocentesis procedure of the patient. The family decided to terminate. In the histopathological examination performed after termination, abnormal findings in the 524 gram male phenotype fetus were; had six fingers on each hand and a single nostril. The patient, who had no bleeding or additional complaints on the 1st day after termination, was discharged with recommendations.
 

Results

Holoprosencephaly is a serious malformation that can present with a wide variety of congenital brain anomalies and facial deformities. The overall prognosis for holoprosencephaly depends on the severity of the craniofacial malformation and whether it is accompanied by chromosomal abnormalities or other syndromes. Although long-term survival with alobar holoprosencephaly has been demonstrated previously, it is considered a fatal malformation.[1] 

Conclusion

First trimester or early second trimester evaluation is vital for detailing the craniofacial examination and detecting possible cases of holoprosencephaly. The case we have presented once again demonstrates the importance of fetal ultrasonography and detailed cranial examination.

Keywords

Cebocephaly, holoprosencephaly, polydactyly, fetal anomaly

1. Winter TC, Kennedy AM, Woodward PF: Holoprosencephaly: a survey of entity, with embryology and fetal imaging. RadioGraphics 2015;35:275–290. 
2. Callahan, J., Harmon, C., Aleshire Jr, J., Hickey, B., & Jones, B. (2017). Alobar holoprosencephaly with cebocephaly. Journal of Diagnostic Medical Sonography, 33(1), 39-42.
3. Simon EM, Barkovich AJ: Holoprosencephaly: new concepts. Magn Reson Imaging Clin North Am 2001;9: 149–164. 
4. Simon EM, Hevner RF, Pinter JD, et al: The middle inter- hemispheric variant of holoprosencephaly. AJNR Am J Neuroradiol 2002;23:151–155 
5. Monteagudo A. Holoprosencephaly. American Journal of Obstetrics & Gynecology. 2020, 223(6), B13-B16. 

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	Fig.1 Monoventricular view and fused thalamus
	Fig.2 Image of cebocephaly