Department of Pathology, Hospital Universitari de Bellvitge, [Bellvitge Biomedical Research Institute] IDIBELL, Feixa Llarga S/N., 08907. L'Hospitalet de Llobregat, Barcelona, Spain.
Diagn Pathol. 2020 Jun 3;15(1):68. doi: 10.1186/s13000-020-00983-3.
Yolk sac tumor (YST) is a germ cell neoplasm that arises predominantly in the gonads, but can also derive from somatic neoplasms in extragonadal locations. These latter cases have been documented in several organs, although reports from the urinary tract are limited. To our knowledge, this is the first report of a bladder urothelial carcinoma with a predominant component of YST differentiation.
We present a unique case of a 76-year-old man with a recurrent urinary bladder tumor, initially interpreted as a high grade urothelial carcinoma with glandular differentiation. In the recurrent tumor, diverse histological patterns were identified, including glandular, hepatoid and sarcomatoid. This tumor showed positivity for AFP, GLP3 and SALL4, and negativity for CK7 and EMA. Fluorescent in situ hybridization study showed a polysomic pattern of chromosome 12. All these findings led to the final diagnosis of a YST derived from urothelial carcinoma.
YST differentiation should be considered in the differential diagnosis of a high grade urothelial carcinoma, particularly when glandular and other unusual patterns are observed.
卵黄囊瘤（YST）是一种生殖细胞肿瘤，主要发生在性腺，但也可源自性腺外部位的体细胞肿瘤。这些后者病例已在多个器官中得到记录，尽管来自泌尿道的报道有限。据我们所知，这是首例报道的以 YST 分化为主的膀胱尿路上皮癌。
我们报告了一例 76 岁男性的复发性膀胱肿瘤，最初被解读为高级别尿路上皮癌伴腺体分化。在复发性肿瘤中，发现了多种组织学模式，包括腺体、肝细胞样和肉瘤样。该肿瘤对 AFP、GLP3 和 SALL4 呈阳性，对 CK7 和 EMA 呈阴性。荧光原位杂交研究显示染色体 12 的多倍体模式。所有这些发现导致最终诊断为源自尿路上皮癌的 YST。
在高级别尿路上皮癌的鉴别诊断中应考虑 YST 分化，特别是当观察到腺体和其他不寻常模式时。
