Retroperitoneal extragonadal germ cell tumor without distant metastasis: a case report

A 66-year-old man was referred to our hospital for an incidentally detected 40-mm mass located at the inter-aortocaval area around the renal hilum. Positron emission tomography CT revealed high accumulation (SUV_max 12.382) without distant metastasis. Bilateral testes were normal by ultrasonography and physical examination, but the serum AFP level was increased to 1161 ng/mL. The pathology based on trans-duodenal needle biopsy demonstrated a yolk sac tumor; therefore, we diagnosed him with retroperitoneal primary germ cell tumor. Due to old age, the potential toxicity of systemic chemotherapy, and no significant signs of invasion to adjacent organs, we performed surgical resection. Although the AFP level decreased to 13.2 ng/mL postoperatively, it increased to 553 ng/mL 2 months after surgery without clinical recurrence on imaging studies. Four cycles of a VIP regimen (VP-16, ifosfamide, and CDDP) were performed, and the AFP level normalized to 2.4 ng/mL. The patient is now disease-free 1 year and 6 months after surgery.