Hair collar sign BY : MOHAMMED ALSAIDAN
Jan 17, 2016
Hair collar sign
BY: MOHAMMED ALSAIDAN
Hair collar sign
• Ring-like hypertrichosis consisting of coarser and longer hair surrounding a congenital alopecic lesion on the midline of the scalp.
• A marker of cranial dysraphism, including encephaloceles, meningoceles, Cutaneous meningothelial tumors (heterotropic brain tissue), dermoid cyst , aplasia cutis congenita, Dandy Walker malformation or agenesis of the corpus callosum
• Due to neuroectodermal abnormalities in embryonic development of the cranial neural tube
Hair collar sign
• Encephaloceles and meningoceles communicate directly to the central nervous system by herniation of intracranial structures through a scalp defect
• Heterotropic brain tissue is found with an intact cranium and no connection to the brain
Associations
• Port wine stain
• Subcutaneous hemangioma • the presence of a vascular malformation with a second cutaneous
marker heightens the likelihood of dysraphism
• Cardiac defect ( e.g. VSD)
• Oculoectodermal syndrome : include epibulbar dermoids and other ocular abnormalities, skin hyperpigmentation, congenital heart defects, urinary tract malformations, and neoplasms
• Syndactyly , cleft lip and palate, sclerocornea, scalp epidermal nevus, lipodermoid also have been reported
Approach
• Present at birth ? Growing in size ? Bulging with crying ?
• Thorough physical examination with neurologic evaluation
• Brain MRI
• Screening for spinal abnormalities (spine, spinal cord)
• Genetic counseling ? Translocation t(1;4) (q44;q10).
• Abdominal ultrasound, metabolic screening