A Case of Paratubal Serous Borderline Tumor Driven by a Somatic BRAF Mutation in an Adolescent Patient

Background: We describe a rare paratubal serous borderline tumor occurring in an adolescent and provide insight into its molecular underpinnings. Case: A 14-year-old girl presented with irregular menstrual cycles and a large right pelvic mass. Computed tomography imaging revealed a cystic neoplasm arising from the right ovary with peripheral calcification. During laparotomy, a cystic tumor located at the right parametrium independent of the fallopian tube was identified. The ovary was intact and the tumor was successfully removed. Intraoperative diagnosis using the frozen section technique and subsequent pathology revealed a paratubal serous borderline tumor. Molecular analyses revealed a chromosomally stable tumor genome and a pathogenic somatic mutation (c.1799 T > A, p.Val600Glu) in the B-Raf proto-oncogene, serine/threonine kinase (BRAF) gene. Summary and Conclusion: This case shows that the BRAF p.Val600Glu mutation likely acts as an oncogenic driver in this rare neoplasm.