191 Angiosarcoma of the Hard Palate: A Rare pediatric presentation with a unique molecular profile

Introduction/Objective Angiosarcoma is a rare and aggressive malignancy that predominantly affects adults, primarily involving the skin. It is exceedingly rare in the pediatric population, and involvement of the oral cavity associated with TP53 mutation and ­MED15::FOSB fusion has not been reported. This case represents a rare presentation of high-grade angiosarcoma in a child with a unique molecular profile. Methods/Case Report We present a previously healthy 11-year-old boy with a primary lesion located in the hard palate, associated with pain and intermittent bleeding. An incisional biopsy demonstrated irregular anastomotic vascular channels with marked nuclear pleomorphism, hyperchromasia, and frequent mitosis. Immunohistochemistry was strongly positive for CD31, ERG, and D2-40, confirming a diagnosis of high-grade angiosarcoma. The tumor was negative for HHV-8, Desmin, and S-100, excluding Kaposi sarcoma and other conditions. The patient is being managed with four cycles of chemotherapy. Results NA Conclusion To our knowledge, this is the first case reported of a high-grade angiosarcoma arising in a child’s hard palate associated with TP53 mutation and MED15::FOSB fusion. Angiosarcomas represent a challenge, and an adequate evaluation beyond vascular markers is pivotal for the appropriate diagnosis.