Extragonadal Yolk Sac Tumor Limited to the Myometrium: Report of a Case With Potential Fertility Preservation and Molecular Analysis Suggesting Germ Cell Origin

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 ...
Source: International Journal of Gynecological Pathology - Category: Pathology Tags: PATHOLOGY OF THE CORPUS: CASE REPORTS Source Type: research