Numb chin syndrome in Ewing sarcoma

The numb chin syndrome consists of unilateral hypesthesia of the chin and l ower lip. In adults, it is often associated with metastatic disease to the mandible, base of the skull, or leptomeninges. In children, it has been ass ociated with infiltration of the inferior alveolar nerve by leukemic cells. We describe two cases of numb chin syndrome in children with Ewing sarcoma . In a child with a solid tumor, this symptom seems to have an ominous mean ing and should lead to the investigation of progressive skeletal involvemen t.