Granular cell tumor of the scrotum in a child with Noonan syndrome.

Granular cell tumor is a rare neoplasm thought to be of neural origin, composed of cells with distinctive granular cytoplasm. Granular cell tumors most often arise on the tongue, but can occur at any body site, and therefore initial presentation to dermatologists is common. We report a granular cell tumor of the scrotum in a child with Noonan syndrome, known to have a mutation in the PTPN11 gene. No previous reports of granular cell tumor of the scrotum in a child are found. The tumor is usually benign; however, it can have a high local recurrence rate (variable between 2% and 50% dependent on whether initial excision is complete and on the occurrence of an infiltrative growth pattern) and therefore long-term follow-up is necessary. This case highlights the occurrence of granular cell tumor, a diagnosis not to be missed by the dermatologist. In addition, we postulate the possible role of PTPN11 mutations in the development of granular cell tumor.