Arhinia

Arhinia

Description

Absence of all nasal structures [arhinia] is almost invariably seen in association with holoprosencephaly. There may be concomitant cyclopia, ethmocephaly or midline cleft lip. The correlation between face and brain in holoprosencephaly suggests an intimate relationship between the developing prosencephalon and the neural crest cells which give rise to the frontonasal process. Variation in severity may occur because of differences in magnitude, timing or susceptibility. Occasional examples of arhinia, without holoprosencephaly are reported, often in association with hypoplasia of the maxilla and a highly arched palate. The nasal cavity is completely absent and there is bony choanal atresia. All cases have been sporadic. Rare features accompanying arhinia have included iris coloboma, microphthalmia, hypertelorism, meningocele or submucous cleft palate. Unilateral absence of nasal structures has also been described. One nostril is absent and may be replaced by a proboscis, skin tag or blind dimple. The ipsilateral eye may be microphthalmic, absent or anomalous. Orofacial clefting is rarely associated.

Diagnosis

The spectrum of anomalies accompanying holoprosencephaly are best appreciated ultrasonographically if several planes are visualised. The sagittal plane evaluates the fetal profile, including forehead, nose, upper and lower lip and jaw. This view is the most useful in identification of a proboscis or absence of nasal structures. A coronal view through facial structures involving both orbits, maxilla and the anterior portion of the mandible in one vertical plane will reveal single, fused or closely spaced orbits, abnormalities of sphenoid and ethmoid bones and the integrity of the nose and lips. A transverse or axial plane slightly caudal to the one commonly used for determination of the biparietal diameter will evaluate the orbit(s) and upper lip. Orbital biometry can be performed in this plane. Recently, a new technique of three dimensional ultrasound visualization using surface and volume rendering has been developed. The application of this technology may enhance imaging of the fetal face and resolve some of the difficulties inherent in distinguishing between the malformations of the cyclopia-cebocephaly-ethmocephaly-midline cleft face spectrum.

Differential Diagnosis

In ethmocephaly a proboscis is located between closely set eyes. In cyclopia a proboscis is situated above a single eye, or fused eyes in a single orbit. In cebocephaly a small flattened nose with a single nostril is situated below hypoplastic, hypoteloric orbits.

Sonographic Features

All nasal structures are absent

The midline of the upper lip is missing – absent prolabium

Rarely there is unilateral absence of nasal structures

Associated Syndromes

  • Acalvaria holoprosencephaly-facial dysmorphism
  • Agnathia holoprosencephaly-tetramelia
  • Aicardi
  • Alcohol
  • Aqueductal stenosis
  • Brachial amelia cleft lip/palate
  • CHARGE association
  • Chromosomal
  • Craniosynostosis holoprosencephaly
  • Diabetes insipidus
  • Coloboma-alobar holoprosencephaly
  • Ectopia cordis embryonal neoplasms
  • Familial
  • isolated
  • Goldenhar
  • Grote
  • Hartsfield
  • Holoprosencephaly-fetal hypokinesia
  • Holoprosencephaly-NTD-nerve palsy-deafness
  • Hydantoin
  • Lambotte
  • Lip synechia imperforate anus
  • Majewski variant chondrodysplasia
  • Martin
  • Maternal diabetes
  • Meckel-Gruber
  • Meckel-like (Fried)
  • Median cleft face other anomalies
  • Pallister-Hall
  • Pseudotrisomy 13
  • Steinfeld
  • Thomas
  • Velo-cardio-facial

References

  1. Hunter AGW In Human Malformations and Related Anomalies Oxford University Press, New York: p 27-38
  2. McGahan JP, Nyberg DA, Mack LA Sonography of facial features of alobar and semilobar holoprosencephaly AJR 154: 143-8
  3. Nyberg DA, Mack LA, Bronstein A, Hirsch J, Pagon RA Holoprosencephaly: prenatal sonographic diagnosis AJR 149: 1051-8
  4. Cohen MM Jr Perspectives on holoprosencephaly: part 1. Epidemiology, genetics and syndromology Teratol 40: 211-235
  5. Hegge FN, Prescott GH, Watson PT Fetal facial abnormalities identified during obstetric sonography J Ultrasound Med 5: 679-684
  6. Schinzel A, Savoldelli G, Briner J, Schmid W Prenatal ultrasonographic diagnosis of holoprosencephaly two cases of cebocephaly and two of cyclopia Arch Gynecol 236: 47-53
  7. Toth Z, Csecsei K, Szeifert GT, Papp Z Prenatal diagnosis by ultrasound of midface defects associated with holoprosencephaly Acta Chirurgica Hungarica 29: 215-221
  8. Hsieh F-J, Lee C-N, Wu C-C, Ko T-M, Kao M-L, Wong A-H, Chen M-L, Chen H-Y Antenatal ultrasonic findings of craniofacial malformations J Formosan Med Assoc 90: 551-4
  9. de Elejalde MM, Elejalde BR Visualisation of the fetal face by ultrasound J Craniofac Genet Dev Biol 4: 251-7
    Greene MF, Benacerraf BR Frigoletto FD Jr Reliable criteria for the prenatal sonographic diagnosis alobar holoprosencephaly Am J Obstet Gynecol 156: 687-9
  10. Lee A, Deutinger J, Bernaschek G Three dimensional ultrasound: abnormalities of the fetal face in surface and volume rendering mode Br J Obstet Gynecol 102: 302-6
  11. Turner GM, Twining P The facial profile in the diagnosis of fetal abnormalities Clin Radiol 47: 389-395
  12. Pretorius DH, Nelson TR Fetal face visualization using three-dimensional ultrasonography J Ultrasound Med 14: 349-356
  13. Bundy AL, Lidov H, Soliman M, Doubilet PM Antenatal sonographic diagnosis of cebocephaly J Ultrasound Med 7: 395-8
  14. Cohen MM Jr In Human Malformations and Related Anomalies Oxford University Press, New York: p 323-4