Chapter 11. Congenital Nasal Anomalies

Nasal development occurs during weeks 4 through 10 of gestation. Migrating neural crest cells populate the frontonasal prominence, one of five facial prominences, and form the nasal or olfactory placodes. These placodes appear as convex thickenings on the surface ectoderm of the frontonasal prominence. A central depression deepens in the placodes to form the primitive nasal pit. Mesenchymal proliferation during the 5th week around the nasal placodes allows the horseshoe-shaped medial and lateral nasal prominences to develop and fuse to form the nostrils. The nasal pits grow toward the oral cavity and develop into the early nasal fossae. The nasobuccal membrane separates the nasal cavities from the oral cavity. This membrane subsequently disappears, allowing for communication of the nasal cavities with the oral cavity, forming the primitive posterior nasal choanae. The nasomedial process gives rise to part of the nasal septum and the medial crus of the lower lateral alar cartilage. The nasolateral process develops into the external wall of the nose, nasal bones, upper lateral cartilage, alae, and lateral crus of the lower lateral cartilage. The apex and dorsum of the nose develop from the frontonasal process (Figure 11–1).

The proposed classification of congenital nasal deformities separates them into four categories. Type I deformities represent hypoplasia and atrophy, Type II are hyperplasia and duplications, Type III are clefts, and Type IV deformities consist of neoplasms and vascular anomalies.

Arrhinia is a rare congenital absence of the nose. The findings include absence of nasal bones, cribriform plate, and nasal septum. In cases of total arrhinia, the olfactory system is also absent. Arrhinia can be associated with other craniofacial anomalies and midline defects.

The likely embryologic abnormality resulting in arrhinia is thought to be a failure of the nasal placodes to invaginate during the 5th week of fetal development. Most cases reported are sporadic, although cases of genetic aberration have been described.

A computed tomography (CT) or magnetic resonance imaging (MRI) scan is performed to plan for surgery and often reveals associated abnormalities. Radiological examination demonstrates small or absent nasal bones and bony masses obstructing the nasal cavity.

All cases require airway management in the neonatal period. Reconstructive surgery is usually postponed until 4–6 years of age. Surgery is often performed in multiple stages, using techniques such as forehead flaps, rib grafts, and tissue expansion.

Unilateral nostril agenesis is a rare malformation frequently associated with other facial anomalies, including proboscis lateralis, abnormalities of the lacrimal system, and malformations of facial bones. Etiology of heminose is unclear, and in the reported cases, this malformation has occurred sporadically. The lack of a nasal placode is thought to lead to heminasal abnormality. Radiographic examination may reveal unilateral absence of the cribriform plate. Surgical reconstruction is usually performed around 4–6 years of age and involves a complex multistaged procedure.

Essentials of Diagnosis

• Presents with respiratory difficulty due to nasal obstruction at birth or shortly thereafter.
• Examination reveals bony obstruction at the nasal vestibule.
• CT scan is usually performed to confirm the diagnosis.

Congenital nasal pyriform aperture stenosis is a rare cause of airway obstruction in newborns and was first described in 1989. A bony overgrowth of the medial maxilla leads to narrowing of the nasal inlet. Because neonates are obligate nasal breathers, presenting signs and symptoms include respiratory distress, cyclical cyanosis or apnea that is relieved with crying, feeding difficulties, and, in severe cases, life-threatening total airway obstruction. Depending on severity of stenosis, symptoms can occur at birth or shortly thereafter. Examination of the nose reveals a bony obstruction in the vestibule and an inability to pass a catheter or endoscope into the nose. Pyriform aperture stenosis can be found either in isolation or together with other malformations, including submucous cleft palate, absence of the anterior pituitary gland, hypoplastic maxillary sinuses, hypotelorism, and a flat nasal. Up to 60% of nasal pyriform aperture stenosis is associated with a single central maxillary incisor. These patients should be further evaluated for holoprosencephaly.

A CT scan through the midface is usually performed to confirm the diagnosis and delineate the anomaly. On CT imaging, nasal pyriform aperture stenosis is diagnosed when the transverse diameter of each aperture is less than 3 mm or combined aperture width is less than 8 mm. In addition, brain MRI or CT allows evaluation of associated pituitary or midbrain abnormalities.

Management of congenital nasal pyriform aperture stenosis depends on the severity of the symptoms. The primary goal is to establish a safe airway. In mild cases, nasal obstruction can be managed conservatively with topical nasal decongestants, corticosteroids, suctioning, or humidification. Symptoms may resolve as the child continues to grow. In severe cases, a McGovern nipple or oral airway can be used. If the infant fails to respond to medical treatment, loses weight, has cyclical cyanosis, or develops pulmonary hypertension from the obstruction, surgical repair is recommended. Transnasal and sublabial approaches to pyriform aperture stenosis repair have been described, sublabial being a preferred method.

Essentials of Diagnosis

• Bilateral cases present at birth with respiratory distress.
• Unilateral cases may present later in life with unilateral nasal obstruction or nasal discharge.
• CT scan confirms the diagnosis.

Choanal atresia is a congenital obstruction of the posterior nasal apertures. This abnormality occurs in one out of every 5000–7000 live births and affects females twice as often as males. It can occur unilaterally or bilaterally with unilateral atresia being more common. Choanal atresia has been described as bony, membranous, or mixed membranous-bony, with the mixed membranous–bony atresias being most common and occurring in 70% of cases. Possible etiology of choanal atresia includes persistence of the buccopharyngeal membrane from the foregut, failure of perforation of the nasobuccal membrane, abnormal persistence or location of mesoderm forming adhesions in the nasochoanal region, and misdirection of neural crest cell migration.

Choanal atresia is associated with other anomalies in half of the cases. The most commonly described association is with CHARGE (Coloboma of the eye, Heart malformations, Choanal Atresia, Retarded growth or development, Genital or urinary abnormalities, Ear malformations or deafness). Increased rates of choanal atresia have been associated with abnormalities in vitamin A metabolism and with prenatal use of thionamides (eg, methimizole or carbimizole).

Neonates are obligate nasal breathers during the first 3–5 months of life; therefore, choanal atresia leading to nasal obstruction may present as respiratory distress and require emergent intervention. Infants with bilateral choanal atresia present with a cyclical cyanosis that improves with crying and worsens with feeding. Unilateral choanal atresia occurs more frequently in the right choana and may present later in life with unilateral nasal obstruction and persistent nasal discharge. The initial diagnosis usually occurs upon an examiner's inability to pass a small catheter or flexible endoscope through the choana.

The diagnosis is confirmed with a CT scan of the paranasal sinuses and skull base. Radiographic imaging allows for examination of the entire nasal cavity, helps to characterize the nature and severity of the anatomic deformity, and also differentiates other causes of nasal obstruction. On CT imaging, choanal atresia is diagnosed if the posterior choanal orifice measures less than 0.34 cm unilaterally or if the posterior vomer measures greater than 0.55 cm (Figure 11–2).

The initial treatment, particularly of bilateral choanal atresia, is to establish a safe airway. Oral airway, McGovern nipple, or intubation can be used as temporary measures. When the patient is stable for general anesthesia, definitive surgical correction of the atresia can be performed.

Several surgical repair techniques have been described. The transnasal approach involves passing dilators under direct vision with either a 120° endoscope or mirror to make an opening in the atretic plate. This technique is fast and involves less blood loss. The transpalatal approach is more often reserved for older patients with unilateral atresia. Although there are better visualization and higher success rates, palate growth can be disrupted, which frequently leads to palate and cross-bite deformities. Endoscopic technique is more difficult to perform in a neonate's nose. An endoscope is used to visualize the atretic plate. The plate is perforated either under direct vision through the nose or using dilators. The opening is then enlarged by removing the posterior part of the septum with back-biting through-cutters, microdebrider, or guarded drill.

To prevent restenosis, stents are placed into the opened choanae and left in place for 2–6 weeks. Application of mytomycin C has been used to reduce postoperative restenosis. However, because of the long-term concerns with the application of a potentially oncogenic medication, routine use is not recommended.

Success rates for surgical repair of choanal atresia range from 55% to 85%. Failure results when the choanae become obliterated by granulation or scar tissue. Recurrences can occur between 2 months and 6 years and often require further surgical correction or dilations. Recently, repeated balloon dilation has been used successfully to treat recurrent choanal atresia.

Polyrrhinia or true nasal duplication is presence of two external noses. One embryologic theory to describe this malformation involves the development of two pairs of nasal placodes, which then undergo the usual development. Frequently, bilateral choanal atresia is also present. Midline craniofacial clefts may result in anomalies presenting as nasal duplications or bifid nose. The atresia is corrected first, followed by excision of the medial portions of each external nose for cosmetic improvement.

A supernumerary nostril is an extra opening lateral, medial, or superior to the normal nostril. The supernumerary nostril can be unilateral or bilateral; it can open into a common cavity shared with the normal nostril or have its own blind-ending cavity. Supernumerary nostrils have been associated with choanal atresia and pyriform aperture abnormalities. Embryologically, this structure may result from a localized abnormality of the lateral nasal process in which a fissure appears accidentally during mesenchymal proliferation. A supernumerary nostril may be excised as a wedge, closing the normal nasal tissue primarily.

Proboscis lateralis is described as a rectangular, tubular, rudimentary nasal appendage that is 1–3 cm long and 1 cm wide. The lesion is located along the embryonic fusion line between the anterior maxillary process and the frontonasal process, and it is most often connected to the medial canthus; however, attachment location can be variable. A central tract is lined with stratified columnar epithelium and usually ends blindly.

It is often associated with abnormalities of the ipsilateral eye. The ipsilateral heminose and face are often anomalous. Imaging to identify bony nasal and paranasal sinus anatomy and possible intracranial adnormalities is recommended prior to surgical repair. Surgical technique to reconstruct the proboscis is based on the anatomical characteristics of the proboscis and should be undertaken when the patient can safely undergo surgery.

Clefts usually result in hard and soft tissue deficiencies and are often associated with other craniofacial anomalies. Tessier proposed a classification of facial, craniofacial, and laterofacial clefts. Facial clefts involving the nose are Tessier 0, 1, 2, and 3. Tessier 0 cleft is the most common craniofacial cleft. It passes through the central midface and can present as a widening, duplication, or agenesis/hypoplasia of the midline structures.

Essentials of Diagnosis

• Usually present as a slow-growing nasal mass or midline cutaneous defect, often with hair protruding from the site.
• Dermoids do not compress or transilluminate.
• MRI is useful for diagnosing intracranial extension.

Nasal dermoid cysts are found in the midline of the nose as masses, sinus tracts, or as a combination of the two. They are derived from ectoderm and mesoderm, are lined by keratinized stratified squamous epithelium, and can contain hair follicles, sweat glands, and sebaceous glands. It is postulated that dermoid develops as a result of failure of dura to separate from nasal skin during development. Dermoid tract or sinus can form anywhere along the nose from the glabella down to the nasal tip or columella, with the most common site being the lower third of the nasal bridge. Up to 45% of nasal dermoid cysts have an intracranial connection (Figure 11–3A).

Nasal dermoids are usually diagnosed within the first 3 years of life. Patients may present with an intermittent discharge of sebaceous material from a cutaneous defect or inflammation. Hair protruding from the site is pathognomonic (Figure 11–4). Nasal dermoids are firm, slow-growing, noncompressible masses that do not transilluminate. They do not enlarge with crying or Valsalva maneuvers and demonstrate a negative Furstenberg test by not expanding with the compression of ipsilateral jugular veins.

CT scan imaging is useful for visualizing bony defects of the skull base. Findings of bifid anterior crista galli and enlarged foramen cecum suggest intracranial involvement of the dermoid. With CT imaging, false-positive and false-negative results regarding intracranial involvement are not uncommon. In general, MRI is more sensitive and specific than CT. It is, therefore, preferred for visualizing soft tissues and diagnosing intracranial extension. Nasal dermoid cysts appear isointense on T1-weighted images and hyperintense on T2-weighted images.

Untreated nasal dermoid cysts can lead to local inflammation or abscess formation. With the presence of an intracranial connection, they may result in cerebrospinal fluid (CSF) leakage, meningitis, cavernous sinus thrombosis, or periorbital cellulitis. Gradual expansion of nasal dermoid cysts can deform nasal bones or cartilages.

Nasal dermoid cysts and sinuses, in general, should be surgically removed to avoid complications. Any surgical intervention of nasal dermoid cysts should be preceded by full evaluation, including MRI to evaluate for intracranial extension. If intracranial extension is present, a neurosurgical evaluation is required and craniotomy is generally performed as part of the procedure. The nasal portion of the dermoid can be removed using any one of various incisions, including midline vertical, transverse, lateral rhinotomy, or mid-brow. The external rhinoplasty approach allows good surgical exposure and superior cosmetic result. Cartilaginous grafts are sometimes needed for dorsal augmentation when normal nasal structures have been altered by the mass. More recently, intranasal endoscopic approaches have been used to resect nasal dermoid cysts, including their removal from the dura.

Recurrence rates for nasal dermoid cysts are as high as 50–100% when dermal elements are incompletely removed; however, when these elements are completely removed, the prognosis is better, although facial scarring, saddle nose deformity, or other nasal structure abnormalities can persist.

Essentials of Diagnosis

• Usually present at birth as a midline nasal mass, nasal obstruction, or CSF leak.
• Encephaloceles are compressible, trasilluminate and enlarge with crying.
• MRI is preferred for evaluation.

Nasal encephaloceles occur as a result of herniation of intracranial tissues through skull base defect (Figure 11–3B). The herniated tissue can contain meninges (meningocele), meninges and brain (meningoencephalocele), or meninges, brain, and part of the ventricular system (meningoencephalocystocel). They are always associated with the midline skull defect, and pathogenesis is thought to result from failure in separation of surface ectoderm from neuroectoderm around the time of neural tube closure.

The most common location for encephalocele is occipital (75%), followed by frontal (25%). Frontal encephaloceles are divided into sincipital (60%) and basal (40%). Sincipital encephaloceles appear as external nasal masses and, based on their location, are classified as nasofrontal, nasoethmoidal, and nasoorbital.

Nasal encephaloceles generally present at birth as bluish, soft, pulsatile, and compressible masses near glabella. Patients may have hypertelorism or dislocation of the nasal bones or septum (Figure 11–5). Occasionally, these lesions present with CSF rhinorrhea or meningitis. Encephaloceles transilluminate, enlarge with crying and Valsalva maneuvers, and have a positive Furstenberg test, observation of mass expansion with compression of the jugular veins.

Imaging is important in assessment of suspected encephalocele and associated intracranial anomalies. MRI is the preferred imaging modality. It delineates a continuity of CSF space and can clearly differentiate nasal encephaloceles from nasal gliomas. On MRI scans, encephaloceles usually appear hyperintense on T2-weighted images and of variable intensity on T1-weighted images. CT imaging is most useful for visualizing bony defects of the skull base.

Untreated, nasal encephaloceles carry the risk of CSF leak as well as associated infections that include meningitis and intracranial abscesses. In addition, nasal encephaloceles may increase in size over time, leading to progressive facial deformity.

Treatment of encephaloceles is surgical resection and requires a multidisciplinary approach. Surgical procedure involves closure of the dural and skull base defects through craniotomy, followed by removal of the extracranial component and reconstruction of external bony defects.

Essentials of Diagnosis

• Usually present at birth.
• Gliomas are non-compressible and do not trasilluminate.
• MRI is preferred for evaluation.

Nasal gliomas are similar to encephalocele, but with obliterated intracranial connection (Figure 11–3C). Nasal gliomas are thought to have a similar embryologic origin as nasal encephalocele. About 15–20% of nasal gliomas have a fibrous stalk connection to the intracranial space.

Nasal gliomas are usually diagnosed at birth or in early childhood. They rarely have associated bony or intracranial abnormalities and carry a low risk for meningitis and CSF leak. Sixty percent of nasal gliomas are extranasal, 30% are intranasal, and 10% are both. Extranasal gliomas are most commonly found along the nasal dorsum and are usually firm, noncompressible masses with a negative Furstenberg test and do not transilluminate. These masses are often purple or gray and can have surface telangiectasias, which explains a frequent misdiagnosis as nasal hemangiomas. Intranasal gliomas can present as pale mass in the nasal cavity causing nasal congestion and obstruction.

MRI is a preferred method for evaluation of nasal dorsal masses and helps to distinguish nasal gliomas from hemangiomas and encephaloceles. Nasal gliomas appear hypo- or isointense on T1-weighted images and hyperintense on T2-weighted images.

Management of nasal glioma consists of surgical excision. Depending on its size, external gliomas can be excised through an external rhinoplasty approach, midline nasal incision, or bicoronal approach. Intranasal gliomas can be excised with endoscopic techniques.

Essentials of Diagnosis

• Usually not present at birth, appear within the first few months of life.
• MRI is most appropriate for evaluation.

Hemangioma is the most common benign tumor in children. These lesions are normally not present at birth and appear within the first few months of life. They undergo a proliferative phase at 3–9 months of age, followed by quiescence and a variable involution phase after 1 year of age.

Hemangiomas can affect any part of the head or neck, including the nose (Figure 11–6). Facial hemangiomas greater than 4 cm can have associated central nervous system malformations. MRI is the most appropriate imaging modality for evaluation.

Most of the hemangiomas regress spontaneously. In comparison to other sites, nasal hemangiomas may have a lower rate of involution. If hemangiomas do not obstruct vision, impair the airway, or distort facial features, they can be observed. Lesions that do not regress and that lead to airway obstruction, facial distortion, bleeding, or thrombocytopenia require more aggressive intervention.

Corticosteroids have been a first line of treatment. Interferon-alpha, vincristine, and surgical excision are other modalities that have been used in treatment of hemangiomas. Recently, reports have been published showing significant improvement of hemangiomas, including nasal hemangioma, with propranolol.

We would like to acknowledge Christina J. Laane, MD for her contribution to this chapter in the previous editions of CDT.