Nasal dermoid
Overview
Nasal dermoid (nasal dermoid sinus cyst, NDSC) is a benign congenital midline nasal mass resulting from incomplete separation of neuroectoderm from surface ectoderm during embryonic development.[1] It is the most common congenital midline nasal lesion, accounting for 61% of such masses, followed by nasal glioma (30%) and encephalocele (9%).[2]
Nasal dermoids occur in approximately 1 in 20,000 to 40,000 live births with a slight male predominance.[3] The lesion may present as a subcutaneous cyst, a sinus tract with a visible punctum on the nasal dorsum, or both. Critically, 10-45% of nasal dermoids have intracranial extension,[1] making preoperative imaging essential to surgical planning. Complications include recurrent infection and, in cases with intracranial connection, meningitis and brain abscess.[4]
History
Nasal dermoids have been recognized since antiquity, with detailed descriptions appearing throughout medical literature.[5] In 1910, Sessions described the potential for intracranial extension of nasal dermoids through the foramen cecum. Bradley and Singh provided a comprehensive classification of nasal dermoid presentations in 1982.
Understanding the embryologic relationship between nasal dermoid, nasal glioma, and encephalocele as variants of the same developmental abnormality helped unify management principles.[6] The development of MRI in the 1980s revolutionized preoperative assessment by allowing reliable identification of intracranial extension, guiding surgical planning.[5]
Pathophysiology
Relevant Anatomy
Embryologic development:
The pathogenesis relates to closure of the anterior neuropore:[1]
- At 3-4 weeks of gestation, the anterior neuropore closes
- A dural projection (prenasal space) temporarily extends through the developing frontal bones between the nasal bones and cartilaginous nasal capsule
- This dural diverticulum normally retracts by the 8th week
- The fonticulus frontalis (future foramen cecum) then closes
Pathogenesis of nasal dermoid:
- During retraction, surface ectoderm may become entrapped along the pathway of the dural projection
- The entrapped ectoderm forms a dermoid cyst or sinus tract
- A fibrous stalk may persist connecting the dermoid to the intracranial space
Key anatomical landmarks:
- Foramen cecum: Bony opening at cribriform plate; may be enlarged if intracranial connection present
- Crista galli: Dermoid tract may extend to or around this structure
- Anterior cranial fossa: Site of intracranial extension
Classification by location:
- External (subcutaneous): Most common presentation
- Intranasal: Within nasal cavity
- Intracranial: Extension through skull base (10-45% of cases)[1]
Disease Etiology
Histopathology:
- Epithelium-lined cyst (stratified squamous epithelium)
- Dermal appendages within wall:[1]
- Hair follicles (pathognomonic when protruding from pit)
- Sebaceous glands
- Sweat glands
- Keratinous debris within cyst
- May show inflammatory changes if infected
Distinguishing from related lesions:
The Furstenberg test (compression of jugular vein or straining) is key to differentiation:[6]
- Nasal dermoid: Non-compressible, does not transilluminate, negative Furstenberg test
- Encephalocele: Enlarges with crying/Valsalva, transilluminates, positive Furstenberg test
- Nasal glioma: Non-compressible, does not transilluminate, negative Furstenberg test, but may have stalk connection
| Lesion | Contents | Intracranial connection | Transillumination | Furstenberg Test |
|---|---|---|---|---|
| Nasal dermoid | Ectodermal derivatives (hair, skin appendages) | 10-45% (fibrous stalk) | Negative | Negative |
| Nasal glioma | Glial tissue (astrocytes) | 15-20% (fibrous stalk, no CSF) | Negative | Negative |
| Encephalocele | Brain/meninges with CSF | Always (patent) | Positive | Positive |
Diagnosis
Patient History
Clinical presentation:
- Age: Usually present at birth or early infancy; 60% diagnosed by age 5[1]
- Pit or punctum: Visible opening on nasal dorsum (pathognomonic when present)
- Hair protruding from pit: Pathognomonic for dermoid cyst[1]
- Subcutaneous mass: Firm, non-compressible, midline or paramedian
- Recurrent infections: Cellulitis, abscess from infected cyst
- Intermittent sebaceous discharge: May be observed from skin ostium[1]
Location of dermoid:
- Glabella and nasal root (most common)
- Nasal dorsum
- Columella
- Nasal tip
Key clinical features:
- Does not transilluminate
- Does not increase with crying or Valsalva (negative Furstenberg test distinguishes from encephalocele)[6]
- May enlarge slowly over time (accumulated debris)
- Hypertelorism and broadened nasal bridge may be present in larger lesions (approximately 50% of cases)[1]
Physical Examination
External examination:
- Firm, non-tender, non-compressible midline nasal mass[6]
- Skin dimple, pit, or punctum (present in approximately 50%)[1]
- Hair protruding from pit (when present, highly specific)[1]
- Mass does not transilluminate
- Negative Furstenberg test (no enlargement with crying or straining)[6]
- Telecanthus, broadening of nasal dorsum (large lesions)
Nasal endoscopy:
- May see intranasal component
- Usually near septum
- Important for surgical planning
Warning signs of intracranial extension:
- History of meningitis
- Very superior location at glabella
- Large lesion size
Laboratory Tests
Laboratory tests are generally not needed for diagnosis.[1]
- CSF analysis: If meningitis suspected
- Beta-2 transferrin: If CSF leak suspected (rare in dermoid cysts)
Imaging
MRI (imaging modality of choice):[5]
- Essential to evaluate for intracranial extension[1]
- Superior soft tissue characterization and identification of intracranial extension[7]
- Findings:
- Well-defined midline cystic mass
- T1-weighted: Variable signal (depends on contents)
- T2-weighted: Typically hyperintense
- Fat-containing components may be present
- Tract extending to foramen cecum/crista galli (if intracranial extension)
- Dural enhancement if inflamed
High-resolution CT:
- Evaluates bony anatomy and skull base involvement[1]
- Findings:
- Nasal bone defect
- Enlarged foramen cecum (suggests intracranial connection)
- Bifid crista galli (associated finding)
- Widened nasal bones
Key imaging findings suggesting intracranial extension:
- Foramen cecum >4 mm
- Bifid crista galli
- Visible tract extending through skull base[7]
- MRI has higher predictive value than CT for detecting intracranial extension[7]
Differential Diagnosis
The three main congenital midline nasal masses are:
- Nasal dermoid (61% of midline masses)[2] - ectodermal derivatives, negative Furstenberg test
- Nasal glioma (30% of midline masses)[2] - ectopic glial tissue, negative Furstenberg test, 15-20% intracranial connection[6]
- Encephalocele (9% of midline masses)[2] - brain/meninges with CSF, positive Furstenberg test, transilluminates
Other differential considerations:
- Dacryocystocele (lateral location at medial canthus)
- Hemangioma (soft, compressible, bluish, transilluminates)
- Epidermoid cyst (no dermal appendages)
- Lipoma
- Frontonasal meningocele/meningoencephalocele
Management
Medical Management
There is no effective medical management for nasal dermoid. Surgical excision is the definitive treatment.[1]
Preoperative considerations:
- Treatment of acute infection before definitive surgery
- Antibiotics for infected dermoid/abscess[1]
- Incision and drainage if abscess present (definitive surgery delayed)
- Multidisciplinary approach (otolaryngology and neurosurgery) recommended for lesions with suspected/confirmed intracranial extension[3]
- Preoperative imaging (MRI ± CT) essential for surgical planning[5]
Surgical Management
Surgical excision is the treatment of choice:[4]
Goals of surgery:
- Complete excision of cyst and tract (essential to prevent recurrence)[1]
- Removal of any intracranial extension
- Acceptable cosmetic outcome
- Prevention of recurrence
Surgical approaches (depend on extent of lesion):[1]
Vertical midline incision:
- For small, external lesions with no intracranial extension
- Direct access to cyst
- May require elliptical excision around punctum
External rhinoplasty approach:
- Better visualization for larger lesions
- Allows dissection along nasal dorsum
- Good cosmetic result[1]
Open rhinoplasty with bicoronal flap:
- For lesions with suspected/confirmed intracranial extension
- Allows craniofacial exposure
- Combined with neurosurgical approach if needed
Endoscopic transnasal approach:
- For intranasal component
- May be combined with external approach
Craniotomy:
- Required for lesions with proven intracranial extension
- Bifrontal craniotomy or small window craniotomy allows exposure of anterior cranial fossa[1]
- Tract followed and excised to dural attachment
- Dural defect repaired to prevent CSF leak
Surgical principles:
- Complete excision essential to prevent recurrence (failure to completely excise results in 10-40% recurrence rates)[1]
- Trace any tract to its termination
- If tract enters skull base, craniotomy warranted
- Skull base reconstruction if defect created
- Meticulous hemostasis
- Consider placing drain to prevent hematoma
Outcomes
Complications
Untreated nasal dermoid:
- Recurrent infection (cellulitis, abscess)[1]
- Meningitis (if intracranial connection)[1]
- Brain abscess
- Progressive enlargement with cosmetic deformity
- Nasal obstruction
- Osteomyelitis (with intracranial involvement)[1]
Surgical complications:
- Recurrence: 10-40% if incompletely excised[1]
- CSF leak (if intracranial extension)
- Meningitis: Risk if intracranial connection not completely removed[1]
- Scarring/cosmetic deformity
- Nasal deformity (if extensive dissection)
- Bleeding
- Infection
Prognosis
Excellent outcomes with complete surgical excision:
- Cure rate >95% with complete excision[1]
- Recurrence typically due to incomplete initial removal
- Cosmetic outcomes generally good, especially with appropriate approach selection
- No malignant potential
- Low recurrence rates (0-5%) with adequate surgical technique and multidisciplinary approach[3]
Factors affecting outcome:
- Complete excision is the most important prognostic factor[1]
- Intracranial extension increases surgical complexity
- Prior infection/surgery may complicate dissection and increase recurrence risk
Follow-up:
- Clinical examination for signs of recurrence
- Imaging if recurrence suspected (recurrence typically presents within 2-5 years post-op)
- Long-term prognosis excellent after complete excision
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 Dermoid Cyst. StatPearls Publishing. 2024. Cite error: Invalid
<ref>tag; name "StatPearls2024" defined multiple times with different content - ↑ 2.0 2.1 2.2 2.3 Rahbar R, Resto VA, Robson CD, et al. Nasal glioma and encephalocele: diagnosis and management. Laryngoscope. 2003;113(12):2069-2077.
- ↑ 3.0 3.1 3.2 Pediatric nasal dermoid sinus cysts: advances in pathogenesis, management strategies, and translational research—a multidisciplinary management perspective. Frontiers in Pediatrics. 2025. Cite error: Invalid
<ref>tag; name "Frontiers2025" defined multiple times with different content - ↑ 4.0 4.1 Wardinsky TD, Pagon RA, Kropp RJ, et al. Nasal dermoid sinus cysts: association with intracranial extension and multiple malformations. Cleft Palate Craniofac J. 1991;28(1):87-95.
- ↑ 5.0 5.1 5.2 5.3 Hedlund G. Congenital frontonasal masses: developmental anatomy, malformations, and MR imaging. Pediatr Radiol. 2006;36(7):647-662.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 The Differential Diagnosis of Congenital Developmental Midline Nasal Masses: Histopathological, Clinical, and Radiological Aspects. Diagnostics. 2024;13(17):2796. Cite error: Invalid
<ref>tag; name "DiffDiag2024" defined multiple times with different content - ↑ 7.0 7.1 7.2 Nasal dermoid cyst. Radiopaedia. 2025. Cite error: Invalid
<ref>tag; name "RadiopaediaMRI" defined multiple times with different content