Imaging Studies
Imaging studies are useful in helping to establish the diagnosis of Proteus syndrome and in tracking the progression of the disease. The following imaging studies may be useful:
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Radiography of the skull, vertebral column, long bones, and pelvis: The most characteristic forms of overgrowth are macrodactyly, clinodactyly, asymmetrical hypertrophy of a limb, vertebral body abnormalities, and hyperostosis. [23]
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Comparative radiographic study of the hands and feet: The most characteristic non-cutaneous features are progressive asymmetric macrodactyly, hemihypertrophy of any part of the skeleton, scoliosis and spinal canal stenosis, macrocephaly, and exostoses, especially of the skull.
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Intracranial MRI: This is an essential initial examination to evaluate for malformations of the CNS that may be associated with mental retardation or seizures. Such findings may include multiple meningiomas, polymicrogyria, and periventricular heterotopias.
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Abdominal MRI: Even in the absence of symptoms, abdominal MRI is important to exclude intra-abdominal lipomas. If present, these can behave aggressively, invading adjacent structures.
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High-resolution chest CT scanning: This examination may be useful in evaluating pulmonary cystic malformations.
Other Tests
See the list below:
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Skin biopsy: Skin biopsy should be considered to confirm the clinical diagnosis of a cerebriform connective-tissue nevus. See Proteus syndrome diagnostic criteria, category A, in Physical.
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Genetic testing is available for the AKT1 gene.
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Electroencephalography: Although most patients appear to be of normal intelligence, mental retardation may occur. Seizures have also been reported.
Procedures
The ongoing evaluation of the patient with Proteus syndrome should include the following procedures [17] :
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Serial clinical photography
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Consultation with a dermatologist, followed by biopsy if indicated
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Consultation with an orthopedic surgeon, followed by surgical treatment if indicated
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Ongoing treatment from a geneticist, pediatrician, or both
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Consultations with a neurologist and an ophthalmologist
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Referral to family support group
Histologic Findings
The histologic findings in Proteus syndrome are specific to the particular type of lesion. The histology of cerebriform connective-tissue nevi and epidermal nevi are discussed in History and Physical, along with a description of their clinical manifestations.
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Epidermal nevus of the trunk follows the Blaschko lines.
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Cerebriform connective-tissue nevus on the plantar surface.
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Overall clinical aspect.
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Proteus syndrome with hemihypertrophy of the limbs.
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Proteus syndrome with gigantism of the feet and macrodactyly.
