Primary Mesenteric Malignant Yolk Sac Tumor: A Case Report.

Primary mesenteric malignant yolk sac tumor (YST) is clinically rare, with challenges in preoperative diagnosis and poor prognosis. This article reports a case of a 34-year-old female with primary YST originating from the transverse mesocolon. The patient presented with an asymptomatic abdominal mass, markedly elevated AFP (31 252 ng/mL), and imaging findings of a well-circumscribed solid mass. The diagnosis was confirmed via laparoscopic surgical resection and pathological examination. This case aims to explore the multimodal diagnostic strategies, therapeutic controversies, and prognostic characteristics of mesenteric YST, providing clinical insights for the identification of this rare tumor.