Departments of Pathology.
Oncology.
Am J Surg Pathol. 2020 Apr;44(4):516-525. doi: 10.1097/PAS.0000000000001402.
Trophoblastic neoplasms involving the ovary are uncommon and include gestational tumors, which are either metastatic from the uterus or ectopic and nongestational tumors, which include those of germ cell type/origin and somatic tumors with trophoblastic differentiation; in all these types, most are pure choriocarcinoma. Intermediate trophoblastic tumors, which include placental site trophoblastic tumor (PSTT) and epithelioid trophoblastic tumor (ETT), are rare in the ovary, with most assumed to be gestational; this is the only category formally recognized in 2014 World Health Organization (WHO) classification, likely due to few well-documented nongestational examples. We report the clinicopathologic features of 6 ovarian intermediate trophoblastic tumors, including 3 PSTTs, 2 ETTs, and 1 ETT with choriocarcinomatous differentiation. DNA-based short tandem repeat genotyping identified 4 of these as nongestational (3 PSTTs and 1 ETT), as evidenced by sharing of alleles between tumor and normal tissue at all informative loci. Interestingly, all 3 of the nongestational PSTTs coexisted with mature cystic teratoma. The remaining 2 tumors (1 ETT and 1 ETT with some choriocarcinomatous differentiation) were gestational (likely ectopic due to lack of evidence of a uterine tumor), as evidenced by the presence of both maternal and novel/nonmaternal alleles at informative loci in tumor compared with normal tissue. It is important to recognize a distinct category of primary ovarian nongestational intermediate trophoblastic tumors of germ cell type/origin, including PSTT and ETT, in classification systems to guide clinical management, as gestational and nongestational tumors have different genetic origins and may require different therapy. Genotyping is useful for classification as nongestational versus gestational, particularly as traditional clinicopathologic findings cannot always predict the nature of a trophoblastic tumor.
卵巢滋养细胞肿瘤并不常见，包括妊娠性肿瘤，其要么是来自子宫的转移瘤，要么是异位的非妊娠性肿瘤，包括生殖细胞类型/起源的肿瘤和具有滋养细胞分化的体细胞肿瘤；在所有这些类型中，大多数是纯绒毛膜癌。中间型滋养细胞肿瘤，包括胎盘部位滋养细胞肿瘤（PSTT）和上皮样滋养细胞肿瘤（ETT），在卵巢中罕见，大多数被认为是妊娠性的；这是 2014 年世界卫生组织（WHO）分类中唯一正式认可的类别，可能是由于很少有记录良好的非妊娠性病例。我们报告了 6 例卵巢中间型滋养细胞肿瘤的临床病理特征，包括 3 例 PSTT、2 例 ETT 和 1 例具有绒毛膜癌分化的 ETT。基于 DNA 的短串联重复基因分型鉴定出其中 4 例为非妊娠性（3 例 PSTT 和 1 例 ETT），这是由于肿瘤和正常组织在所有信息性位点上的等位基因共享。有趣的是，所有 3 例非妊娠性 PSTT 均与成熟囊性畸胎瘤共存。其余 2 例肿瘤（1 例 ETT 和 1 例 ETT 伴有一些绒毛膜癌分化）是妊娠性的（由于缺乏子宫肿瘤的证据，可能是异位的），这是因为与正常组织相比，肿瘤中在信息性位点存在母体和新的/非母体等位基因。在分类系统中认识到一种独特的原发性卵巢非妊娠性生殖细胞来源的中间型滋养细胞肿瘤类别，包括 PSTT 和 ETT，这很重要，因为妊娠性和非妊娠性肿瘤具有不同的遗传起源，可能需要不同的治疗。基因分型对于分类为非妊娠性与妊娠性很有用，特别是因为传统的临床病理发现不能总是预测滋养细胞肿瘤的性质。
