Multiple giant pilomatricoma in familial Sotos syndrome.

Cerebral giantism or Sotos syndrome consists of a pre- and postnatal overgrowth whose genetic basis are mutations and deletions of the nuclear receptor-binding SET domain containing protein gene. These patients have an increased risk of developing neoplasms, especially in adulthood. We report a 9-year-old boy, diagnosed with familial Sotos syndrome, who had two pilomatrixoma, symmetrically located on both sides of the neck, measuring 4 cm in diameter. Genetic study of the tumor tissue showed deletion of exon 22 of the NSD1 gene, whereas beta-catenin gene mutations were not detected. To the best of our knowledge, presentation of multiple pilomatricomas with Sotos syndrome has never been reported. Therefore their association probably is incidental. Nevertheless, the unusual size of our patient's pilomatricomas could be due to deletion of the NSD1 gene, which characterizes Sotos syndrome.