Author: Dr Elizabeth A Connelly, Dermatologist, New Plymouth, New Zealand. Chief Editor: Adjunct A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, July 2017.
Macrocephaly-capillary malformation (MCM) was first described in 1997 and is characterised by:
Additional features include variable degrees of asymmetric somatic overgrowth, distal limb malformations, and hyperelasticity. Fewer than 300 cases have been reported in the literature.
MCM also known as megalencephaly-capillary malformation syndrome, and megalencephaly-capillary malformation-polymicrogyria (MCAP) syndrome, to reflect very large brain size, large head size, and polymicrogyria that characterise the syndrome.
MCM/ MCAP affects boys and girls equally with no ethnic predilections. It occurs sporadically.
Some cases of MCM/MCAP have been found to have somatic mutations in the phosphatidylinositol 3-kinase, catalytic, alpha polypeptide (PIK3CA) gene on chromosome 3q26.
Major criteria: both must be present
Minor criteria: variable involvement
Diagnosis is made based on clinical signs and neuro-imaging studies. Both major criteria should be present, with variable minor criteria.
Baseline magnetic resonance imaging (MRI) of the brain and spine is recommended at the time of diagnosis.
MCAP should be distinguished from other overgrowth syndromes with vascular malformations including:
Patients with MCM/MCAP require ongoing medical surveillance as well as physical and occupational therapy. Early intervention is helpful to overcome disability and achieve developmental milestones.
Patients are at increased risk of developing meduloblastoma, meningioma, Wilms tumour and leukaemia over their lifetime.
In addition to yearly medical exams, all patients should have cardiology consultation at the time of diagnosis.
Follow-up imaging recommendations include:
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