Orbital rhabdomyosarcoma in Noonan syndrome.

The incidence of various benign and malignant tumors is increased in patients with Noonan syndrome compared with the general population. We present a 9-year-old boy with the typical features of Noonan syndrome and an acute nonaxial proptosis of the right eye. An ultrasound scan, a computed tomography scan, and magnetic resonance imaging raised suspicion of rhabdomyosarcoma. Biopsy confirmed the diagnosis. The tumor was consequently treated with combined chemotherapy and radiotherapy. Rhabdomyosarcoma is a rare but important differential diagnosis of tumor formation in children with Noonan syndrome and may arise in the orbit.