What is the pathogenesis of aplasia cutis congenita?
No unifying underlying cause. If midline think neural tube defect; in lateral cases, incomplete closure of embryonic fusion lines
What are the clinical manifestations of aplasia cutis congenita?
Solitary .5-10cm (usually not multiple) well-demarcated round to stellate areas of no epidermis, dermis and sometimes subcutis and calvarium
- Leaves an alopecic scar
- Can present as ulcer, erosion or glistening membrane
- Look for “hair collar sign” which is a congenital rink of dense, dark, and coarse hair around the area of aplasia cutis or other congenital scalp lesion
Where does aplasia cutis congenita occur most commonly?
Most (up to 90%) occur on the scalp
What is the histology of aplasia cutis congenita?
The epidermis is atrophic
- Superficial dermis replaced by loose connective tissue w/ absent adnexal structures
- Hair collar shows hypertrophic clustered hair follicles
When should radiologic studies be done in aplasia cutis congenita?
Should get MRI if there is concern for extension to or calvarial defect
What are the treatment options for aplasia cutis congenita?
No intervention for small lesions
- If large (>4cm) then can consider excision to minimize hemorrhage, meningitis and thrombosis
- If it is located in midline and associated with a palpable component, higher risk of calvarial/CNS defect –> get imaging
What is Adams-Oliver syndrome?
Aplasia cutis w/ cranial defect + congenital heart defects +limb abnormalitites
What genetic conditions are associated w/ aplasia cutis congenita?
Adams Oliver syndrome
Bart syndrome (aplasia cutis + DDEB)
Trisomy 13
Ectodermal dysplasias
Amniotic band syndrome
What non-genetic conditions can be associated w/ aplasia cutis congenita?
Teratogen exposure: Methimazole is common
Other midline/closure defects: omphalocele, gastroschisis, spinal dysraphism, meningomyelocele, focal dermal hypoplasia
- Congenital infections (VZV, HSV)
What is the pathogenesis of nasal glioma?
It is ectopic neuroectoderm
Clinical features of nasal glioma?
Firm, non-compressible, nontender usually skin-colored (can be blue-red) nodule at the root of the nose; can occur in extra nasal (60%) or intranasal (30%) locations
What is the treatment for nasal glioma?
Excision, these are stable over time and there is no intracranial extension
What is the pathogenesis of meningocele/encephalocele?
Herniation of cranial contents through skull defect –> the neuroectoderm did not properly separate from surface ectoderm in early gestation
Clinical findings of meningocele/encephalocele?
A compressible subcutaneous nodule that transilluminates, usually located at the occiput
- Also can occur on dorsal nose, orbits, and forehead
What is the histology of meningocele/encephalocele?
Type of neural tissue tells you if encephalocele versus meningocele (encephalocele has meningeal and glacial tissue vs meningeal only for meningocele)
What is the treatment for meningocele/encephalocele?
Excision, enlarge w/ increased intracranial pressure as a result of connection w/ CNS
Associations with meningocele/encephalocele?
Can be associated with a brain malformation, hypertelorism, facial clefting, presence of hair collar sign, capillary stain, and mass –> high suspicious for cranial dysraphism
What is the pathogenesis of accessory tragus?
Congenital –> faulty development of the first branchial arch
What is the clinical appearance of an accessory tragus?
Exophytic papule, with or without cartilage, occurs anywhere from preauricular region to angle of mouth
- Can be single or multiple and can be bilateral
What is the histology of an accessory tragus?
Tiny hair follicles amidst connective tissue, sometimes w/ cartilaginous core
What is the tx of of an accessory tragus?
Careful excision (the cartiledge if present can be continuous w/ the external ear canal)
Dz associations with an accessory tragus?
Typically isolated
- Can be associated with other branchial arch syndromes like oculoauriculovertebral syndrome or Goldenhar syndrome
What is Goldenhar syndrome?
Incomplete development of the ear, nose, soft palate, lip, and mandible on usually one side of the body. Other organs can be affected
Can be associated with deafness and granular cell tumors
What is the pathogenesis of congenital rests of the neck (wattles)?
Remnants of branchial arches; occur along branchial arch fusion lines
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Darier Disease and Hailey-Hailey Disease22
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Neurocutaneous Syndromes54
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Premature Aging Syndromes and Poikilodermas48
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Primary Immunodeficiencies69
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Ichthyoses, Erythrokeratodermas, and Related Disorders97
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Palmoplantar Keratodermas40
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Pigmentary Disorders109
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Lentiginoses Syndromes22
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Tumor Syndromes43
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Developmental Abnormalities50
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Inherited Vascular Disorders67
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Disorders of the Hair/Nail/Ectodermal dysplasias45
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Metabolic and Nutritional40
