Department of Pathology and Laboratory Medicine, Vancouver General Hospital.
University of British Columbia.
Appl Immunohistochem Mol Morphol. 2020 Sep;28(8):593-601. doi: 10.1097/PAI.0000000000000801.
Mesonephric carcinoma is a rare gynecologic neoplasm commonly mistaken for clear cell carcinoma, because of their overlapping morphologic features. Both tumors are negative for estrogen receptor and p16, magnifying this diagnostic dilemma. Recently, hepatocyte nuclear factor-1 beta (HNF-1β), a marker for clear cell carcinoma, has also been shown to be positive in mesonephric carcinomas. Other more recent markers for clear cell carcinoma, however, such as Napsin-A and alpha-methylacyl-CoA racemase (AMACR), have not yet been studied in mesonephric carcinomas. Here we examine HNF-1β, AMACR, and Napsin-A immunohistochemistry in 18 mesonephric and 55 endometrial/cervical clear cell carcinomas. HNF-1β was considered positive if nuclear staining was present in ≥70% of cells and at least moderate intensity; for Napsin-A and AMACR, any cytoplasmic staining was considered positive (≥1%). H-scores were determined by multiplying the intensity score by proportion score. HNF-1β was positive in a substantial portion of mesonephric carcinomas (9/18, 50%; H-score 98) and clear cell carcinomas (34/55, 62%; H-score 163) and did not distinguish between the 2 entities (specificity, 50%; P-value of H-score=0.08). Napsin-A and AMACR expression was significantly higher in clear cell [43/55 (78%) and 41/55 (75%), respectively] than mesonephric carcinomas [4/18 (22%) and 4/18 (22%) respectively], and helpful in this differential (specificity: 78% and 78%; P<0.05 for both). When Napsin-A and AMACR staining were seen in mesonephric carcinomas, staining was focal (≤5%), whereas staining in clear cell carcinomas was patchy/diffuse. In summary, Napsin-A and AMACR are helpful in distinguishing mesonephric carcinomas from clear cell carcinomas of the female genital tract, but HNF-1β is not.
中肾管癌是一种罕见的妇科肿瘤，常被误诊为透明细胞癌，因为它们具有重叠的形态特征。这两种肿瘤都对雌激素受体和 p16 呈阴性，这使得诊断更加困难。最近，肝癌核因子-1β（HNF-1β），一种透明细胞癌的标志物，也被证明在中肾管癌中呈阳性。然而，其他最近用于透明细胞癌的标志物，如 Napsin-A 和α-甲基酰基辅酶 A 消旋酶（AMACR），尚未在中肾管癌中进行研究。在此，我们检查了 18 例中肾管癌和 55 例子宫内膜/宫颈透明细胞癌中 HNF-1β、AMACR 和 Napsin-A 的免疫组织化学。如果细胞核染色在≥70%的细胞中呈阳性且至少为中度强度，则认为 HNF-1β为阳性；对于 Napsin-A 和 AMACR，任何细胞质染色均为阳性（≥1%）。H 评分通过将强度评分乘以比例评分来确定。中肾管癌中有相当一部分（9/18，50%；H 评分 98）和透明细胞癌（34/55，62%；H 评分 163）呈 HNF-1β阳性，并且无法区分这两种实体（特异性，50%；H 评分的 P 值=0.08）。Napsin-A 和 AMACR 的表达在透明细胞癌[43/55（78%）和 41/55（75%）]中明显高于中肾管癌[4/18（22%）和 4/18（22%）]，并且有助于区分这两种肿瘤（特异性：78%和 78%；P<0.05）。当 Napsin-A 和 AMACR 染色在中肾管癌中出现时，染色为局灶性（≤5%），而在透明细胞癌中染色为斑片状/弥漫性。总之，Napsin-A 和 AMACR 有助于区分女性生殖道的中肾管癌和透明细胞癌，但 HNF-1β 则不然。
