1. Overview – Congenital Lesions of the External Nose

Congenital anomalies of the external nose arise from disruption of embryological development between the 4th and 10th weeks of intrauterine life.
These defects may involve:

• Skin
• Cartilage
• Bone
• Nasal cavity
• Nasal septum
• Paranasal sinuses
• Neural tissue (in encephalocoeles/meningocoeles)

They frequently present in neonates or early childhood but may be detected later when cosmetic deformity becomes obvious or when nasal obstruction develops.

Congenital lesions of the external nose include:

• Congenital nasal deformities
• Choanal atresia (posterior, but included due to congenital nature)
• Dermoid cysts and sinuses
• Gliomas
• Encephaloceles
• Proboscis lateralis
• Arhinia (rare)
• Bifid nose
• Cleft lip nasal deformity
• Congenital septal deviations

This full chapter covers all major congenital external nasal lesions because ENT examiners frequently group them together and students must understand them as a single clinical category.

---

2. Embryology of the External Nose (Foundation for Understanding Pathology)

A detailed understanding of embryology is essential because every congenital anomaly reflects a specific embryological failure.

2.1 Development Starts at 4th Week

• Arises from frontonasal process
• Paired nasal placodes form
• Invaginate to form nasal pits
• These pits deepen into primitive nasal sacs

2.2 Fusion of Processes

The external nose develops from three processes:

• Medial nasal processes → tip, columella, philtrum
• Lateral nasal processes → alae
• Frontonasal process → bridge of nose

Any failure in fusion or abnormal migration → congenital deformities.

2.3 Neural Tube Connection

Some congenital lesions arise due to persistent connections between:

• Brain meninges
• Nasal skin
• Developing skull base

This explains lesions such as:

• Encephalocoele
• Meningocoele
• Nasal glioma
• Dermoid sinus/fistula

2.4 Formation of Nasal Septum

• Derived from the frontonasal process
• Deviations present at birth reflect intrauterine molding

2.5 Formation of Choanae

Primitive choanae fail to canalize → choanal atresia, a major congenital nasal emergency.

---

3. Classification of Congenital External Nasal Lesions

ENT exams commonly ask this classification:

A. Surface & Soft Tissue Lesions

• Dermoid cyst/sinus
• Epidermoid cyst
• Nasal glioma
• Hamartomas
• Hemangiomas (infantile)
• Lymphangiomas

B. Bony & Cartilaginous Deformities

• Bifid nose
• Hypoplastic nose
• Arhinia (absence of nose)
• Proboscis lateralis
• Congenital dorsal hump
• Congenital saddle nose

C. Neural & Meningeal Origin Lesions

• Meningocoele
• Encephalocoele
• Encephalomeningocoele

D. Mixed Deformities

• Cleft lip–associated nasal deformity
• Cleft palate–associated deformity

E. Canalization Defects

• Choanal atresia

F. Septal Abnormalities

• Congenital DNS
• Septal dislocation

---

4. Clinical Assessment Framework for Congenital Lesions

A crucial structured approach required in OSCEs:

History

• Age of onset
• Birth history
• Associated syndromes
• Difficulty breathing
• Feeding problems
• Recurrent infections
• CSF rhinorrhea (suspected encephalocoele)
• Cosmetic concerns

Examination

• Inspection (symmetry, skin pits, masses, deformities)
• Palpation (consistency, compressibility, reducibility)
• Transillumination
• Furstenberg test (expands with crying/sneezing = encephalocoele)
• Intranasal examination
• Check for discharge (mucoid vs CSF)

---

Written And Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change MBBS 4th Year (Fourth Professional) Otorhinolaryngology (ENT) Free Material

---

5. Major Congenital Lesions of the External Nose — Detailed Descriptions

Below begins the ultra-expanded detail, covering pathology, diagnosis, clinical features, imaging, histology, and surgical management.

---

5.1 Dermoid Cyst & Dermoid Sinus of the Nose

Definition

A congenital inclusion cyst that contains:

• Stratified squamous epithelium
• Hair follicles
• Sebaceous glands
• Keratin debris

Dermoid sinuses may have a tract extending to the foramen cecum or dura, so intracranial extension MUST be excluded.

Embryological Basis

Occurs due to:

• Failure of midline fusion between medial nasal processes
• Trapping of ectoderm between them
• Persistence of neuroectodermal tract from dura to nasal skin

This explains why dermoid sinuses may lead to intracranial complications.

Clinical Features

• Midline pit or dimple on nasal dorsum
• May contain hair protruding
• Recurrent discharge from sinus
• Firm, non-compressible swelling
• Infection → redness, pain
• Rarely meningitis (if intracranial connection)

Red Flag

Never attempt to squeeze or biopsy before imaging, due to risk of spreading infection intracranially.

Investigations

• MRI → best for detecting intracranial extension
• CT → bony defect assessment

Management

• Complete surgical excision
• Combined ENT + neurosurgery if intracranial tract present
• Cure is excellent if removed early

---

5.2 Nasal Glioma (Nasal Glial Heterotopia)

Definition

A firm, non-compressible mass of ectopic glial tissue located on the nasal bridge or within nasal cavity.

Embryology

Due to:

• Separated encephalocoele that loses connection
• Prolapse of neural tissue during skull base development

Histology

• Astrocytes
• Glial fibrillary acidic protein (GFAP positive)
• No meninges

Clinical Presentation

• Firm mass on nasal dorsum or sidewall
• Does NOT transilluminate
• Does NOT expand on crying (negative Furstenberg test)
• May cause nasal obstruction if intranasal

Imaging

• MRI to differentiate from encephalocoele
• CT to assess bony defect

Treatment

• Surgical excision
• Avoid biopsy before imaging

---

5.3 Encephalocoele / Meningocoele / Encephalomeningocoele

Definitions

• Meningocoele: Meninges herniate through skull defect
• Encephalocoele: Brain tissue + meninges herniate
• Encephalomeningocoele: Brain + meninges + CSF sac

Embryological Origin

Failure of closure of the anterior neuropore → skull base defect.

Common sites:

• Nasoethmoidal
• Nasofrontal
• Nasoorbital

Clinical Features

• Soft, compressible swelling
• Expands on crying/straining (positive Furstenberg test)
• Bluish tinge
• May obstruct nose
• Risk of meningitis

Investigations

• MRI → Essential
• CT → Bony defect

Management

• Neurosurgical + ENT team
• Excision + repair of skull base

---

Written And Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change MBBS 4th Year (Fourth Professional) Otorhinolaryngology (ENT) Free Material

---

5.4 Proboscis Lateralis

Definition

A rare congenital anomaly where a tubular appendage (proboscis) forms lateral to the nose.

Embryology

Due to failure of formation of the lateral nasal process.

Clinical Features

• Absence or hypoplasia of ipsilateral nostril
• Unilateral facial asymmetry
• Malformed nasal cavity
• Associated anomalies:
  • Cleft lip
  • Holoprosencephaly
  • Microphthalmia

Investigations

• CT + MRI for anatomical mapping
• Ophthalmology evaluation
• Brain imaging

Management

• Multistage reconstructive surgery
• Nasal cavity reconstruction
• Cosmetic correction

Prognosis

Depends on associated craniofacial defects.

---

5.5 Bifid Nose

Definition

A midline split of the external nose due to failure of medial nasal process fusion.

Embryological Basis

Failure of fusion between the two medial nasal processes.

Clinical Features

• Broad, flattened nasal bridge
• Double nasal tip appearance
• Wide columella
• Septal deviation common

Surgical Management

• Reconstruction of nasal dorsum
• Cartilage grafting
• Septoplasty

---

5.6 Arhinia (Congenital Absence of Nose)

Definition

Extremely rare – complete absence of external nose, nasal cavities, and olfactory system.

Embryology

Severe failure of frontonasal process development.

Clinical Presentation

• Severe airway obstruction
• Feeding difficulty
• No smell
• Midface deformity

Investigations

• CT/MRI
• Assessment for holoprosencephaly

Management

• Emergency airway stabilization
• Later reconstructive procedures

---

5.7 Congenital Deviated Nasal Septum (DNS)

Causes

• Intrauterine pressure
• Birth trauma
• Developmental asymmetry
• Syndromic associations

Clinical Features

• Infant:
  • Difficulty breastfeeding
  • Mouth breathing
  • Snoring
• Adult: obstruction, sinusitis

Management

• In infants → repositioning or observation
• Surgery (Septoplasty) after growth completion unless severe

5.8 Cleft Lip Nasal Deformity (CLND)

A major congenital deformity commonly examined in ENT vivas because it unites embryology, anatomy, airway pathology, and reconstructive surgery.

Embryological Origin

• Results from failure of fusion between:

  • Medial nasal process

  • Maxillary process

• Timing: occurs around 6th week of intrauterine life.

• Involves both soft and skeletal tissues because these processes shape:

  • Upper lip

  • Philtrum

  • Nasal floor

  • Alar base

  • Septum alignment

Failure leads to a spectrum of deformities.

---

Spectrum of Deformities in Cleft Lip Nasal Deformity

On the Cleft Side

• Short columella

• Alar cartilage flattened and displaced laterally

• Nasal tip deviated away from cleft

• Alar base displaced laterally, inferiorly, posteriorly

• Septum deviated

• Asymmetric nostrils

• Weak lower lateral cartilage

• Depressed nasal dome

Functional Consequences

• Nasal obstruction

• Impaired airflow

• Snoring in children

• Recurrent infections due to turbulent flow

---

Clinical Assessment

• Inspect for asymmetry

• Note alar collapse

• Assess septal deviation

• Check nasal patency

• Evaluate associated cleft palate

• Identify airway obstruction components

• Speech evaluation if velopharyngeal insufficiency suspected

---

Radiology

• CT face for skeletal assessment

• 3D CT for surgical planning

---

Surgical Management

Primary Repair (3–6 months of age)

• Millard, Mohler, or Mulliken techniques

• Repositioning of alar cartilage

• Septal repositioning

• Correction of nasal sill

• Restoration of symmetry

Secondary Rhinoplasty (adolescence)

• Osteotomies

• Cartilage grafts (septal or auricular)

• Tip refinement

Principles ENT Students Must Know

• Always correct airway first

• Cartilage memory causes recurrence

• Growth considerations limit early aggressive surgery

---

5.9 Infantile Hemangioma of the Nose

Vascular tumors common in infants, often involving nasal tip (“Cyrano nose”).

Embryology & Pathogenesis

• Derived from abnormal angioblastic proliferation

• Endothelial cell overgrowth

• VEGF-driven hyperplasia

Clinical Phases

• Proliferative phase: fast growth during first year

• Plateau phase: 1–2 years

• Involution phase: shrinkage until 7–10 years

Clinical Features

• Raised red or purple mass

• Soft, compressible

• Blanching on pressure

• Nasal obstruction possible if intranasal component present

• Deformity of nasal tip (“bulbous nose”)

Complications

• Ulceration

• Airway compromise

• Cosmetic deformity

---

Diagnosis

• Clinical

• Doppler ultrasound

• MRI for deep lesions

---

Treatment

Medical

• Propranolol – first-line

• Steroids if needed

Laser therapy

• For superficial components

Surgery

• Reserved for residual deformity after involution

---

5.10 Lymphangioma (Lymphatic Malformation of the External Nose)

Definition

Benign congenital malformation of lymphatic vessels.

Embryology

• Failure of lymph sacs to drain into venous system

• Persistence of embryonic lymphatic channels

Clinical Features

• Soft, non-tender swelling

• Translucent appearance

• May enlarge with crying

• Can involve:

  • Nose

  • Cheeks

  • Upper lip

Complications

• Infection

• Sudden enlargement

• Cosmetic deformity

Diagnosis

• Ultrasound

• MRI for extent

Management

• Sclerotherapy (bleomycin, OK-432)

• Excision if feasible

---

Written And Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change MBBS 4th Year (Fourth Professional) Otorhinolaryngology (ENT) Free Material

---

5.11 Congenital Traumatic Deformities

Although technically “acquired at birth,” they are considered congenital.

Causes

• Difficult labor

• Instrumental delivery (forceps)

• Intrauterine compression

• Breech presentation

Common Deformities

• Lateral deviation of nasal tip

• Septal dislocation (most important)

• Greenstick fracture of nasal cartilage

Clinical Features in Neonates

• Snorting

• Difficulty breastfeeding

• Visible asymmetry

• Cyanosis during feeding

Management

• Manual repositioning within 1 week of birth

• Severe cases → early ENT intervention

---

5.12 Syndromic Congenital Nasal Malformations

Many congenital anomalies occur as part of syndromes.

Holoprosencephaly

• Arhinia

• Proboscis

• Cyclopia

Binder Syndrome

• Midface hypoplasia

• Flattened nasal bridge

Down Syndrome

• Depressed nasal bridge

• Small nasal cavities

Charge Syndrome

• Choanal atresia

• External ear anomalies

ENT relevance is early nasal airway assessment in all syndromic infants.

---

5.13 Choanal Atresia (Though Posterior, Always Examined with Congenital Nose Lesions)

Definition

Failure of posterior nasal choanae to develop → blocked nasal airway.

Types

Bony (90%)

Membranous (10%)

Unilateral or Bilateral

Embryology

Persistence of buccopharyngeal (or nasobuccal) membrane.

---

Clinical Features

Bilateral Atresia (Emergency in newborns)

• Cyanosis relieved by crying (classic)

• Difficulty feeding

• Nasal obstruction from birth

Unilateral Atresia

• Chronic unilateral discharge

• Mouth breathing

• Snoring

---

Diagnosis

• Failure to pass catheter through nose

• Fog test (no misting)

• CT scan for definitive diagnosis

---

Management

• Immediate airway stabilization

• Surgical repair via endoscopic approach

• Stenting sometimes used postpartum

---

6. Differential Diagnosis of Congenital Lesions of External Nose

A must-memorize area for examiners.

Midline Mass in Child

• Dermoid

• Glioma

• Encephalocoele

• Epidermoid

• Hemangioma

• Lymphangioma

Mass That Expands on Crying

→ Encephalocoele

Mass That Does NOT Expand

→ Glioma

Mass With Hair in the Pit

→ Dermoid sinus

Blue, Soft, Compressible

→ Hemangioma

Solid, Firm

→ Glioma

Midline Dimple with Recurrent Discharge

→ Dermoid sinus

Nasal Deformity + Cleft Lip

→ Cleft lip nasal deformity

---

7. Radiological Approach to Congenital External Nasal Lesions

7.1 CT Scan

• Bone involvement

• Skull base defect

• Nasal cavity deformity

• Choanal atresia

7.2 MRI

• Soft tissue differentiation

• Intracranial extension crucial in:

  • Dermoids

  • Gliomas

  • Encephalocoeles

7.3 MRI Findings

• T1 bright → fat in dermoid

• T2 bright → CSF in encephalocoele

• No intracranial communication → glioma

---

Written And Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change MBBS 4th Year (Fourth Professional) Otorhinolaryngology (ENT) Free Material

---

8. Histopathology Correlation for ENT Exams

Dermoid Cyst

• Keratinized squamous epithelium

• Hair follicles

• Sebaceous glands

• Keratin debris

Glioma

• Glial cells (GFAP-positive)

• Fibrous stroma

• No meningeal lining

Encephalocoele

• Brain tissue

• Meninges

• CSF-filled sac

Hemangioma

• Proliferating capillaries

• Endothelial hyperplasia

Lymphangioma

• Dilated lymphatic channels

• Lymph-filled spaces

---

9. OSCE Scenarios – Congenital External Nasal Lesions

Case 1: Newborn with Respiratory Distress

Findings:

• Cyanosis unless crying

• Cannot pass catheter

Diagnosis: Bilateral choanal atresia

---

Case 2: Child with Pit on Nasal Bridge with Hair

Findings:

• Midline

• Hair visible

• Recurrent discharge

Diagnosis: Nasal dermoid sinus

---

Case 3: Soft Compressible Swelling in Infant

• Bluish hue

• Compressible

• Fills on crying

Likely: Hemangioma or encephalocoele
Use Furstenberg test.

---

Case 4: Firm Mass on Nasal Bridge

• No transillumination

• No expansion on crying

Likely: Nasal glioma

---

Case 5: Deformed Nose + Cleft Lip

Diagnosis: Cleft lip nasal deformity

---

10. Surgical Principles ENT Students Must Know

General Rules

• Image before biopsy

• Avoid incision on midline pits before MRI

• Preserve normal cartilage

• Correct airway obstruction early

• Cosmetic reconstruction in planned stages

• Skull base lesions require combined approach

---

11. Summary Table – High-Yield for Viva