Malignant transformation of a mature teratoma in the duodenum: A case report.

Introduction: Mature teratomas of the duodenum are extremely rare, with only five cases reported in the English literature and none documented in Vietnam. Malignant transformation within a mature teratoma presents a challenging scenario for diagnosis and management, requiring a nuanced approach to treatment.

Presentation Of Case: We report the first documented case of malignant transformation in a duodenal mature teratoma in Vietnam. A 35-year-old male presented with persistent dull pain in the left flank, anorexia, and melena. Clinical examination revealed a palpable 10 × 14 cm mass in the left hypochondrium. Computed tomography (CT) imaging identified a tumor in the D4 segment of the duodenum with invasion into adjacent structures. The patient subsequently underwent surgical resection of the tumor, followed by adjuvant chemotherapy.

Discussion: Histopathological analysis of the resected mass confirmed a moderately differentiated squamous cell carcinoma arising from a mature teratoma. Malignant transformations within teratomas, especially in such rare locations as the duodenum, require a multidisciplinary approach for optimal patient outcomes. In this case, the combination of surgical and adjuvant therapies was critical to managing the disease.

Conclusion: This case highlights the importance of early recognition and a multidisciplinary approach in managing malignant transformation in duodenal teratomas. The combination of surgery and adjuvant chemotherapy proved effective, with no recurrence or metastasis observed at five months follow-up.