Diseases of the External Nose

Introduction

This chapter provides a structured approach to understanding diseases affecting the external nose, from congenital anomalies to malignant neoplasms. The content is organised to facilitate systematic learning for both undergraduate and postgraduate students, with emphasis on clinical presentation, evidence-based management, and recent advances.

Applied Anatomy of the External Nose

The external nose consists of:

• Bony framework: Nasal bones, frontal process of maxilla
• Cartilaginous framework: Upper lateral cartilages, lower lateral (alar) cartilages, septal cartilage
• Skin and soft tissue: Variable thickness; thinner over the dorsum and thicker over the tip and alae
• Blood supply: Branches of ophthalmic and facial arteries (dangerous area of the face due to valveless veins connecting to cavernous sinus)
• Nerve supply: Trigeminal nerve (ophthalmic and maxillary divisions)

Classification of Diseases of the External Nose

For clinical and academic purposes, diseases can be systematically classified as:

Category	Examples
I. Congenital Deformities	Nasal dermoids, encephaloceles, gliomas, cleft nose
II. Acquired Deformities	Traumatic (saddle nose, crooked nose), Iatrogenic (post-rhinoplasty), Inflammatory (Wegener’s granulomatosis)
III. Inflammatory/Infective Conditions	Vestibulitis, furunculosis, cellulitis, perichondritis
IV. Benign Neoplasms	Rhinophyma, hemangioma, papilloma, pigmented nevi
V. Malignant Neoplasms	Basal cell carcinoma, squamous cell carcinoma, melanoma
VI. Systemic Diseases with Nasal Manifestations	Granulomatosis with polyangiitis, sarcoidosis, relapsing polychondritis

Congenital midline nasal lesions

1. Nasal Dermoid Cysts and Sinuses

Nasal dermoid cysts and sinuses are rare congenital midline lesions containing ectodermal and mesodermal elements. They develop along embryonic fusion lines and form the most common congenital midline nasal lesions. They account for about 3% of all dermoids and 12% of head and neck dermoids. The incidence is approximately 1 in 30,000 live births, with a male-to-female ratio of about 3:1.

Aetiology and Embryology: Nasal dermoids develop when ectodermal tissue becomes trapped during embryonic development. One theory attributes this to incomplete closure of the fonticulus frontalis, allowing dermal tissue to become trapped between the developing nasal bones and cartilage. Another theory involves persistent tissue within the prenasal space, which extends along the midline from the nasal tip toward the brain. A persistent tract may connect the skin with deeper tissues and form a cyst or sinus. The tract may extend intracranially through the foramen caecum and attach to the dura.

Pathological Features: The lesion is lined by stratified squamous epithelium and may contain sebaceous glands, hair follicles and sweat glands. The cyst may also contain keratin and desquamated epithelial debris.

Clinical Presentation: Most lesions present at birth or during early childhood. They usually occur in the midline of the nasal bridge, between the columella and glabella, and may present as a cyst, sinus or fistula. A tuft of hair protruding from the sinus opening is highly characteristic. The swelling is usually non-compressible and may discharge sebaceous material. A sinus opening or visible hair should raise suspicion of an underlying tract and possible intracranial extension. Recurrent infection may occur. Rare complications include nasal bone erosion, periorbital spread, meningitis and brain abscess. Associated anomalies may include hydrocephalus, aural atresia and cardiac abnormalities. Familial cases have also been reported.

Investigations: Use both CT and MRI for surgical planning. MRI is preferred for assessing intracranial extension, sinus tracts, dural attachment and soft-tissue involvement. CT provides better assessment of bony anatomy and may show a bifid crista galli, widened foramen caecum or cribriform plate defect.

Staging System for Nasal Dermoids

Type	Description	Surgical approach
Type I – Superficial	Limited to nasal soft tissue	Direct external excision
Type II – Intraosseous	Extends into nasal or frontal bones	Bony exposure or drill-out
Type III – Intracranial extradural	Extends intracranially without dural attachment	Frontonasal or cranial approach
Type IV – Intracranial intradural	Intracranial extension with dural attachment	Cranial or combined endoscopic-cranial approach

Management: Complete surgical excision is the treatment of choice and usually provides a cure. Early surgery reduces recurrent infection and bony distortion. Choose the approach according to the lesion’s depth and intracranial extension. External rhinoplasty or direct midline excision usually provides good access to superficial and intraosseous lesions. Intraosseous lesions may require osteotomy or careful drilling. Selected lesions may allow an endoscopic approach. Lesions with intracranial extension require careful dissection and often a combined ENT–neurosurgical approach. Surgeons should repair any skull-base defect or CSF leak. Do not biopsy or blindly excise a midline nasal mass before imaging excludes intracranial communication, as an unrecognised tract can cause CSF leak, meningitis or intracranial injury.

Postoperative Care: Monitor for CSF leak, infection and wound complications. Use antibiotics when clinically indicated and nasal packing when required. Long-term follow-up, including MRI when appropriate, can help detect recurrence.

2. Nasal Encephalocele / Meningoencephalocele

A nasal encephalocele occurs when intracranial contents herniate through a congenital defect in the anterior skull base. A meningocele contains meninges and CSF, while a meningoencephalocele also contains brain tissue.

Types: Nasal encephaloceles mainly occur as frontoethmoidal or basal lesions. Frontoethmoidal lesions usually appear as an external midline nasal mass. Basal lesions pass through defects in the cribriform plate or sphenoid and usually present as an intranasal mass, nasal obstruction or CSF rhinorrhoea.

Patients usually present with a midline nasal mass. The mass may enlarge during crying, straining or Valsalva (positive Furstenberg sign). Some lesions may appear pulsatile. Patients may develop CSF rhinorrhoea. Intracranial communication increases the risk of meningitis. MRI is the preferred investigation. It shows brain tissue, CSF, the tract and intracranial extension. CT demonstrates the skull base and bony defect. CT or MR cisternography can help locate a CSF leak when required. Never take a biopsy or blindly excise a midline nasal mass until imaging excludes intracranial communication. An unrecognised encephalocele can cause CSF leak, meningitis or intracranial injury. Treat encephaloceles with surgical repair. Use an endoscopic endonasal approach for suitable basal lesions. Extensive lesions may require a cranial or combined approach. ENT and neurosurgical teams should plan extensive lesions together.

3. Nasal Glioma (Glial Heterotopia)

Nasal glioma is a benign mass of heterotopic glial tissue outside the brain. It is a choristoma, not a true tumour. Most lesions have no intracranial connection or CSF communication. Nasal gliomas usually present during infancy or early childhood as a firm, non-compressible nasal mass. The lesion may occur on the nasal bridge or inside the nasal cavity. Intranasal lesions can cause nasal obstruction. About 60% occur externally, 30% intranasally and 10% in both locations.

MRI is the preferred investigation. It defines the soft-tissue lesion and helps exclude intracranial communication. CT shows the skull base and associated bony defects. Always exclude an encephalocele before biopsy. Treat nasal glioma with complete surgical excision. Choose the approach according to the lesion’s site and extent. Use an external rhinoplasty or lateral nasal approach for suitable external lesions and an endoscopic endonasal approach for suitable intranasal lesions.

4. Cleft Nose

 

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Reference Textbooks.

• Scott-Brown, Textbook of Otorhinolaryngology-Head and Neck Surgery.
• Cummings, Otolaryngology-Head and Neck Surgery.
• Stell and Maran’s, Textbook of Head and Neck Surgery and Oncology.
• Ballenger’s, Otorhinolaryngology Head And Neck Surgery
• Susan Standring, Gray’s Anatomy.
• Frank H. Netter, Atlas of Human Anatomy.
• B.D. Chaurasiya, Human Anatomy.
• P L Dhingra, Textbook of Diseases of Ear, Nose and Throat.
• Hazarika P, Textbook of Ear Nose Throat And Head Neck Surgery Clinical Practical.
• Mohan Bansal, Textbook of Diseases of Ear, Nose and Throat Head and Neck Surgery.
• Hans Behrbohm, Textbook of Ear, Nose, and Throat Diseases With Head and Neck Surgery.
• Logan Turner, Textbook of Diseases of The Nose, Throat and Ear Head And Neck Surgery.
• Arnold, U. Ganzer, Textbook of  Otorhinolaryngology, Head and Neck Surgery.
• Ganong’s Review of Medical Physiology.
• Guyton & Hall Textbook of Medical Physiology.

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