PA23 Primary cutaneous Ewing sarcoma in a 14-year-old boy

Abstract A 14-year-old boy presented with a 7-month history of nodule on the right shoulder. It was initially pink and pea-sized but developed black areas as it grew. nontender bled occasionally. He otherwise well took no regular medications. originally from Philippines, having moved to UK 2 years previously. His mother had breast cancer. This suspected be pyogenic granuloma treated shave biopsy. Histology showed largely patternless sheets small, blue, round cells, diffuse strong membranous reactivity for CD99 immunohistochemistry. Further molecular analysis revealed EWSR1–FLI1 fusion, confirming Ewing sarcoma. Staging imaging metastatic disease. Following further surgery, he per Euro-Ewing protocol vincristine (V), doxorubicin (D), cyclophosphamide (C), ifosfamide (I), etoposide (E; nine induction cycles: alternate VDC/IE followed by five consolidation cycles IE/VC). sarcoma most commonly arises bone is second common malignancy in children an incidence 2.93 million. Primary cutaneous extremely rare, literature consisting case reports. 2015 retrospective review 56 cases cutaneous/subcutaneous France found that were extremities (48%) or trunk (39%). tends occur late-adolescent young-adult females, whereas disease affects younger patients male predominance. Current treatment similar arising bone. However, primary has more favourable prognosis, 5-year overall survival rate 93.8%. In summary, very rare malignancy, particularly paediatric population. important consider this differential diagnosis erythematous nodular lesions children, order minimize delays treatment.