TITLE:
An Extremely Rare Torsion Case of Ovarian Yolk Sac Tumor in Postmenopausal Woman
AUTHORS:
Kenji Niwa, Saki Tsurue, Yuzo Niwa, Yoh Hayasaki, Sakae Mori, Kentaro Niwa, Takuji Tanaka
KEYWORDS:
Yolk Sac Tumor, Postmenopausal, Torsion, Loss of PTEN
JOURNAL NAME:
Open Journal of Pathology,
Vol.16 No.3,
April
29,
2026
ABSTRACT: An extremely rare case of ovarian yolk sac tumor (YST) with adnexal torsion in a postmenopausal woman is presented. A 66-year-old woman visited the emergency department of Gujo City Hospital with lower abdominal pain. Elevated serum AFP levels and preoperative imaging suggested torsion and possible dissemination of ovarian malignancy, and a semi-urgent debulking surgery for suspected ovarian cancer was performed. Histological and cytological examinations confirmed YST with omental dissemination. Immunohistochemistry showed positivity for SALL4 and loss of phosphatase and tensin homolog (PTEN). The final diagnosis was torsion of a pure-type YST originating from the left ovary, staged as pT3CN0M0. No BRCA mutations were detected; however, the genomic instability score was positive (44 > 42). Given the poor expected prognosis, the patient received adjuvant chemotherapy including both bleomycin, etoposide and cisplatin (for germ cell tumors) and paclitaxel, carboplatin, and bevacizumab (for epithelial ovarian carcinoma). Four months after surgery, the patient shows no evidence of recurrence or relapse.