Precocious puberty and Chiari I malformation with syrinx: a case report of an unusual presentation of Costello syndrome

BACKGROUND: Costello syndrome (CS) is a rare RASopathy causing developmental delays, short stature and classically, delayed puberty. We present a patient with CS and central precocious puberty (CPP). CASE PRESENTATION: A female patient with CS presented at 6 years 10 months of age with breast development. CPP was biochemically confirmed at 7 years 1 month of age, no additional pituitary dysfunction was noted and puberty progressed at follow-up. Brain magnetic resonance imaging (MRI) revealed a Chiari I malformation with a syrinx, requiring surgical decompression. The patient was successfully treated with histrelin. CONCLUSIONS: Although recent publications do not recommend routine brain MRI in girls with isolated CPP over 6 years of age, in those with CS actionable MRI findings are more likely and imaging should be performed. It is unclear whether the cerebral malformation in the patient contributed to CPP or was an incidental syndromic finding.