Primary retroperitoneal germ cell tumor in an adult female: A case report.

Primary retroperitoneal germ cell tumors are uncommon and especially rare in female patients. However, this type should be included in the differential diagnosis of retroperitoneal tumors that may metastasize from the gonads and be a primary tumor.An abdominal mass was detected in a 38-year-old woman during physical examination, which was accompanied by left renal obstructive hydrops. She was admitted to our institution for further investigation. The patient had no obvious clinical symptoms, and the levels of serum tumor markers did not signifificantly increase. Abdominal noncontrast enhanced and contrast-enhanced computed tomography revealed a retroperitoneal neoplasm that invaded the left ureter, thereby causing left hydronephrosis.Imaging examination characterized the tumor as malignant based on its invasion in the left ureter. Histopathology and immunohistochemistry confifirmed the resected tumor as a dysgerminoma. The primary gonad-derived germ cell tumor was not found in the pelvis; therefore, the patient was fifinally diagnosed with primary retroperitoneal germ cell tumor.Preoperative examination was completed, and the retroperitoneal mass was resected.During the short-term follow-up, no tumor recurrence was detected.Primary retroperitoneal seminoma should be included in the differential diagnosis of primary retroperitoneal tumors in female patients. The primary retroperitoneal seminoma/anaplastic tumor has an obvious occupying effect and can easily invade the surrounding structures. However, surgical resection of such tumors is an optional treatment strategy.