Extra-skeletal Ewing's sarcoma of the frontal sinus: a rare disorder in pediatric age.

Paediatric sinonasal tumours comprise numerous aetiologies. Ewing's sarcoma (ES) consists of a malignancy of neuroectodermal origin. This type of sarcoma affects mainly children and adolescents and can assume the skeletal or extra-skeletal form. Primary ES of head and neck is extremely rare, accounting for only 4%-9% of all cases. So far, as much as we know, only a few cases of sinonasal ES have been reported in literature. The authors present a case of a previous healthy 12-year-old girl who presented with a rapidly growing and expansive frontal mass and unilateral nasal obstruction. Immunohistochemical, molecular and cytogenetic analysis of the lesion showed diffuse expression of CD56 and CD99 on tumour cells and a translocation involving chromosome 22q12, confirming ES diagnosis.