In Macrocephaly-Capillary Malformation Syndrome (MCM) — also known as megalencephaly-capillary malformation syndrome (MCAP) — patients have a persistent nevus simplex or port wine stains, as well as a large head. Children with this syndrome often also have developmental delays and other body malformations, such as extra or enlarged fingers or toes. Their bodies may not be symmetrical, meaning one side may be larger than another.
Because of abnormalities in the brain, these children may have seizures or an excess amount of fluid in the brain (hydrocephalus). Children with this syndrome may also have very flexible joints. This syndrome is caused by a genetic mutation.
Children with MCM will need to be followed by many specialists. Due to their head size and irregular brain growth, they will need to be followed by a neurologist and may need to see a neurosurgeon. Medication will be used to treat seizures when they occur. Dermatologists can consider treatment of the port wine stains with pulsed dye laser. Plastic surgeons and orthopedic surgeons may be needed to treat abnormalities of the child’s digits. Many practitioners suggest monitoring for a type of kidney cancer, Wilms tumor, in patients with MCM syndrome.