case_images: PMC8240588_01
case_images: Computed tomography (CT) scan of patient with endometrial YST preoperatively. (A) Enlarged uterus equal to pregnancy for 2 months accompanied by occupancy in the uterus cavity; (B) A 3-cm mass of uneven density in the right adnexa.
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case_images: PMC8240588_01_fonc-11-672434-g001.jpg
case_images: f1
case_images: Computed tomography (CT) scan indicated that the image was similar to that of endometrial cancer with the myometrium invasion, accompanied by a 3-cm mass of uneven density in the right adnexa (  Figure 1  ).
case_images: Light microscopic appearance and immunohistochemical staining of endometrial YST. (A) Yolk sac structure (H and E, 10 x 40); (B) CD117+; (C) Germ cell tumor (GCT) cytology (H and E, 10 x 40); (D) Hyaloid drop (H and E, 10 x 40); (E) SALL4+; (F) Schiller-Duval body positive (H and E, 10 x 40).
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case_images: PMC8240588_01_fonc-11-672434-g002.jpg
case_images: f2
case_images: In addition, endodermal sinusoidal (Schiller-Duval body) and hyaloid drop were also observed microscopically (  Figure 2  ).
case_images: PMC8240588_02
case_images: Computed tomography (CT) scan of patient with YST originating from the broad ligament. (A) A 2-cm mass at the right pelvis; (B) Slightly enlarged lymph nodes.
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case_images: f3
case_images: CT scan also indicated a 2-cm mass at the right pelvis (  Figure 3  ).
case_images: Light microscopic appearance and immunohistochemical staining of YST originating from the broad ligament. (A) Yolk sac tumor (H and E, 10 x 40); (B) AE1/AE3+; (C) AFP++; (D) GPC-3(++); (E) Yolk sac tumor (H and E, 10 x 40); (F) Ki-67 positivity rate of approximately 70%; (G) PLAP negative; (H) SALL4 +++.
case_images: fonc-11-672434-g004.jpg
case_images: PMC8240588_02_fonc-11-672434-g004.jpg
case_images: f4
case_images: CK7, CD30, PAX-8, and PLAP (  Figure 4  ). Considering diagnosis with yolk sac tumor, four courses of chemotherapy with BEP regimen were administrated for this patient from