Departments of Obstetrics, Gynecology, and Reproductive Sciences (S.S., M.S., H.S.T.) Pathology (P.H., N.B.), Yale University School of Medicine, New Haven, Connecticut.
Int J Gynecol Pathol. 2020 May;39(3):247-253. doi: 10.1097/PGP.0000000000000601.
Extragonadal pelvic yolk sac tumor (YST) in postpubertal female patients is a rare malignant neoplasm with potentially 2 distinct histogenetic pathways, and no clear treatment algorithm, especially in young patients desiring future fertility. Here we report a case of extragonadal YST arising within the myometrium in a 30-yr-old nulligravid woman. The patient presented with heavy and irregular bleeding, and imaging studies showed an 8.2 cm uterine mass, most consistent with a degenerating uterine leiomyoma. The patient underwent abdominal myomectomy, and intraoperative frozen section evaluation revealed a high-grade malignancy. Because of the patient's strong desire for future fertility, a conservative wedge resection of the surrounding myometrium and surgical staging with uterine closure and retention of the ovaries were performed. On permanent sections the tumor showed an admixture of glandular, reticular, solid and papillary architectural patterns, moderate to marked nuclear atypia and clear cytoplasm with focal eosinophilic hyaline globules. Immunohistochemical stains were diffusely positive for SALL4, AFP, glypican3, and focally positive for CK20, and negative for EMA, and CK7, confirming the diagnosis of extragonadal YST. The endometrium displayed normal secretory phase morphology without involvement by YST, and the myometrial resection margins were negative. Short tandem repeat genotyping analysis of the tumor revealed allelic gains at 7 loci (involving chromosomes 2, 3, 4, 5, 8, 13, and 15) and allelic loss at one locus assessed on chromosome 11, while next-generation sequencing results showed no mutations in 155 genes tested, suggesting germ cell origin. The patient underwent 4 cycles of adjuvant chemotherapy with bleomycin, etoposide, and cisplatin, and she had 1 cycle of successful oocyte cryopreservation 6 months after completing chemotherapy. The clinical follow-up at 12 mo shows no evidence of disease.
青春期后女性盆腔性腺外卵黄囊瘤（YST）是一种罕见的恶性肿瘤，具有 2 种潜在的组织发生途径，目前尚无明确的治疗方案，特别是对于有生育需求的年轻患者。本研究报道了 1 例 30 岁未育女性发生于子宫肌层的性腺外 YST。患者表现为大量且不规则的阴道出血，影像学检查显示 8.2cm 子宫肿块，最符合变性子宫肌瘤。患者接受了腹式子宫肌瘤切除术，术中冷冻切片评估显示为高级别恶性肿瘤。由于患者强烈希望保留生育能力，因此进行了子宫周围肌层楔形切除术和保留卵巢的手术分期，同时关闭子宫。在石蜡切片上，肿瘤显示出腺状、网状、实性和乳头状结构模式的混合，中度至显著的核异型性和局灶性嗜酸性透明小体的清晰细胞质。免疫组织化学染色显示 SALL4、AFP、glypican3 弥漫阳性，CK20 局灶阳性，EMA 和 CK7 阴性，证实了性腺外 YST 的诊断。子宫内膜显示正常的分泌期形态，未受 YST 累及，子宫肌层切缘阴性。肿瘤短串联重复基因分型分析显示 7 个位点（涉及染色体 2、3、4、5、8、13 和 15）的等位基因增益和 1 个位点（染色体 11 上）的等位基因丢失，而下一代测序结果显示在 155 个测试的基因中未发现突变，提示其起源于生殖细胞。患者接受了博来霉素、依托泊苷和顺铂辅助化疗 4 个周期，化疗结束后 6 个月成功进行了 1 个周期的卵母细胞冷冻保存。临床随访 12 个月未见疾病复发。
