El Camino Hospital, Pathology, Mountain View, CA, USA.
University of California San Francisco, Pathology, San Francisco, CA, USA.
Hum Pathol. 2020 Aug;102:54-59. doi: 10.1016/j.humpath.2020.07.006. Epub 2020 Jul 13.
Invasive plasmacytoid urothelial carcinomas (PUCs) are an uncommon aggressive variant, which often shows immunohistochemical loss of E-cadherin, underlying its distinct discohesive histology. The marker P120 (well described in breast pathology as being a diagnostic tool alongside E-cadherin for lobular neoplasia) has not been evaluated in PUCs. Biopsies, transurethral resections, and cystectomies of PUCs were collected, and whole-slide immunohistochemical analysis of E-cadherin and P120 was applied. A subset of cases were also tested for CDH1 mutation. PUC cases were stratified into morphologic categories of classic, pleomorphic, or desmoplastic. For E-cadherin, 24 of 33 (73%) cases showed an abnormal staining pattern, consisting of complete absence of staining (17/24; 71%) or cytoplasmic staining (7/24; 29%). For P120, 24 of 33 (73%) cases showed an abnormal staining pattern, consisting of loss of membranous staining with cytoplasmic reactivity. Only 2 cases showed a discordant E-cadherin/P120 immunoprofile (94% concordance). Significant staining differences among the 3 morphologic categories were not found. CDH1 mutation was found in 4 of 8 (50%) of cases, with 3 of 4 (75%) cases showing matched molecular/immunoprofile reactivity. No cases with CDH1 mutation showed discordant pattern E-cadherin/P120 immunoreactivity. Our rate of aberrant E-cadherin immunoreactivity in PUCs (73%) is similar to a meta-analysis of published cases (74%). We also report an identical rate of aberrant P120 immunoreactivity in PUCs (73%). While PUC remains a histologic diagnosis, in a subset of cases showing a less appreciated pattern (such as desmoplastic) or confounding cytoplasmic E-cadherin reactivity, the utility of paired P120 staining may be a useful diagnostic tool.
侵袭性浆母细胞性尿路上皮癌（PUC）是一种罕见的侵袭性变异型，通常表现为免疫组织化学 E-钙黏蛋白缺失，其独特的分离组织学由此产生。P120（在乳腺病理学中被很好地描述为用于诊断小叶肿瘤的诊断工具，与 E-钙黏蛋白一起使用）在 PUC 中尚未得到评估。收集了 PUC 的活检、经尿道切除术和膀胱切除术，并应用了 E-钙黏蛋白和 P120 的全切片免疫组织化学分析。一部分病例还进行了 CDH1 突变检测。将 PUC 病例分为经典、多形性或促结缔组织增生性形态学类别。对于 E-钙黏蛋白，33 例中有 24 例（73%）表现出异常染色模式，包括完全无染色（17/24；71%）或细胞质染色（7/24；29%）。对于 P120，33 例中有 24 例（73%）表现出异常染色模式，包括膜染色丢失伴细胞质反应性。仅 2 例显示出不一致的 E-钙黏蛋白/P120 免疫表型（94%的一致性）。3 种形态学类别之间未发现显著的染色差异。在 8 例中有 4 例（50%）发现 CDH1 突变，其中 4 例中有 3 例（75%）显示匹配的分子/免疫表型反应性。没有 CDH1 突变的病例显示出不一致的 E-钙黏蛋白/P120 免疫反应性。我们在 PUC 中发现异常 E-钙黏蛋白免疫反应性的比例（73%）与已发表病例的荟萃分析相似（74%）。我们还报告了 PUC 中异常 P120 免疫反应性的相同比例（73%）。虽然 PUC 仍然是一种组织学诊断，但在一些表现出不太明显模式（如促结缔组织增生性）或细胞质 E-钙黏蛋白反应性混杂的病例中，配对 P120 染色的应用可能是一种有用的诊断工具。
