Asymptomatic giant primary Ewing sarcoma of the skull in an adolescent: a case report and review of the literature

BACKGROUND: Primary Ewing's sarcoma of the skull is an exceedingly rare condition, accounting for only 1-6% of cases. It is highly malignant and predominantly affects the long bones and pelvis of children and young adults. Skull involvement is unusual, with the parietal and frontal bones being the most frequently affected. We present a rare case of a giant primary occipital Ewing sarcoma that was clinically asymptomatic. CASE PRESENTATION: A 15-year-old male presented with a 3-year history of a progressively enlarging, painless left parieto-occipital swelling, with accelerated growth over the final 3 months. He remained entirely asymptomatic and neurologically intact. Imaging revealed a giant extradural mass with significant bone erosion and a combined extracranial-intracranial extension. The patient underwent gross total resection of the tumor, which was confirmed to be Ewing sarcoma on histopathology (CD99 and vimentin positive). Postoperative recovery was uneventful, and follow-up imaging showed no recurrence. DISCUSSION: Ewing sarcoma of the skull often presents with symptoms of increased intracranial pressure; however, this patient's asymptomatic course highlights the clinical variability of cranial Ewing sarcoma. Treatment typically involves a combination of surgical resection, chemotherapy, and radiotherapy (RT). While achieving complete resection is challenging owing to the proximity to critical structures, the tumor's strong response to adjuvant therapy offers a favorable prognosis when metastasis is absent. CONCLUSION: This case underscores the importance of a multimodal approach in managing primary cranial Ewing's sarcoma. It emphasizes the need for further studies to evaluate its unique biological behavior and optimal treatment strategies.