Hypothalamic hamartoma related to Pallister-Hall syndrome in an adolescent patient: illustrative case.

Background: Hypothalamic hamartomas in relationship to Pallister-Hall syndrome are extremely rare; just over 100 cases have been reported. Most hypothalamic hamartomas are sporadic. Observation(s): A 17-year-old boy presented with a 3-year history of gelastic seizures and a suprasellar mass. The complete physical examination, blood work, and study images resulted in bilateral mesial-polydactyl, metacarpal syndactyly, glandular hypospadias, and hypoplastic nails. There were no hormone or neurological manifestations. MRI studies demonstrated a large non-enhancing suprasellar mass adjacent to the hypothalamus and displaced normal structures. An open biopsy of the mass and genetic studies were carried out to confirm the presumptive diagnosis. After the biopsy, treatment with Gamma knife and continuation of the anti-epileptic drug was indicated. The patient is seizure-free to this day. Conclusion: Patients with Pallister-Hall hypothalamic hamartomas have a milder clinical scenario than native hypothalamic hamartomas; Pallister-Hall gelastic seizures usually respond well to antiepileptic drugs, and native hypothalamic hamartomas are well-known to be resistant. Even though a very large suprasellar mass could be found, most patients present with premature puberty and/or gelastic seizures, with almost no neurological deficits related to the size of the mass.