Abstract
Endodermal primitive tumors, also known as yolk sac tumors (YSTs), are rare tumors that usually develop in the gonads and are more common in females at premenarchal age. Thus, this report details a rare case of YST in a 13-year-old girl who presented to the Obstetrics and Gynecology outpatient department with complaints of pain and a mass in the abdominal region that had been gradually growing in size for two to three months. The patient also reported a history of weight loss, loss of appetite, intermittent fever, and frequent urination. Per abdomen examination resulted in a mass corresponding to 24 weeks which was firm or hard in consistency with restricted mobility, arising from the pelvis and having an irregular surface. Per rectal examination also reported the same mass on the right side. For investigation magnetic resonance imaging (MRI) was performed that stated the lesion with neoplastic etiology likely arising from the uterus. The treatment plan included a staging laparotomy with a right oophorectomy, bilateral salpingectomy, dissection of the right preaortic and pelvic lymph nodes, and infracolic omentectomy, followed by a course of chemotherapy. The diagnosis of YST was confirmed based on the intraoperative findings and the frozen section report. As this is a rare tumor gynecologists and pediatric physicians should still be aware of this tumor since it can be life-threatening and should be promptly prevented and treated.