Extragonadal yolk sac tumor of the ureter with neuroendocrine differentiation: A case report.

Extragonadal germ cell tumors in the urinary tract are exceptionally rare, with only a small number of cases documented in the literature. Although these neoplasms exhibit considerable histologic heterogeneity, neuroendocrine differentiation within these tumor types have only been reported in isolated number of instances. Here, we report a unique case of a ureteral extragonadal germ cell tumor demonstrating yolk sac tumor-like histologic features with concomitant neuroendocrine differentiation with remarkably rapid progression. Given the aggressive clinical behavior observed, immediate surgical resection was imperative. Furthermore, in cases with neuroendocrine differentiation, adjuvant platinum-based chemotherapy should be strongly considered to optimize postoperative outcomes.