case_images: PMC9396030_01
case_images: Image picture and pathologic images of mesenteric YST. (A) CT scan of mass in the left lower quadrant. (B) Hematoxylin-eosin staining of the mesenteric YST (x200). (C) Immunohistochemical staining of CK was strong positive(x200). (D) Immunohistochemical staining of AFP was strong positive(x200). (E) Immunohistochemical staining of CD117 was weakly positive (x200). (F) Immunohistochemical staining of PALP was weakly positive (x200). (G) Immunohistochemical staining of CDX2 was weakly positive (x200). (H) Immunohistochemical staining of Ki-67 was 50% positive (x200).
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case_images: PMC9396030_01_fonc-12-928234-g001.jpg
case_images: f1
case_images: Computed tomography (CT) scan revealed a soft tissue mass of approximately 143 x 151 x 125 mm in the left lower quadrant with ascites ( Figure 1A ). Her postoperative pathology was YST of mesenteric ( Figure 1B ). The results of immunohistochemistry were as follows: CK (+++), AFP (+++), CD117 (+), PALP (+), CDX2 (+), CD34 (+), EMA (+), CD56 (+), CD20 (+), Ki67 (50% +), and other immune markers were negative ( Figures 1C-G ).
case_images: The changing trend of serum alpha-fetoprotein. BEP, bleomycin, etoposide and cisplatin; TP, docetaxel and carboplatin; VIP, ifosfamide, cisplatin and etoposide; RT, radiotherapy; PD-1*, tislelizumab; VTC, vinorelbine tartrate capsules; TIP, paclitaxel, ifosfamide and cisplatin; VEFGi, bevacizumab. *: Tislelizumab is an anti-programmed cell death protein-1 (PD-1) antibody.
case_images: fonc-12-928234-g002.jpg
case_images: PMC9396030_01_fonc-12-928234-g002.jpg
case_images: f2
case_images: AFP fluctuation was shown in  Figure 2 . A new lesion appeared by
case_images: Chest computed tomography scan. (A) Slight interstitial changes in the lung before BEP  chemotherapy. (B) Slight interstitial changes in the lung after BEP  chemotherapy.
case_images: fonc-12-928234-g003.jpg
case_images: PMC9396030_01_fonc-12-928234-g003.jpg
case_images: f3
case_images: CT scans before and after BEP  chemotherapy, there was no significant change in the interstitium of the lung. ( Figure 3 ). Currently, we plan to treat the patient with TP/TE (paclitaxel, cisplatin/paclitaxel, etoposide) chemotherapy every 3 weeks, but she is severely myelosuppression and poorly tolerated.