From Kasturba Medical College, Manipal Academy of Higher Education (MAHE), Mangalore, Karnataka, India (Ms Sood); and the Departments of Pathology and Surgery (Urology), University of Chicago Medical Center, Chicago, Illinois (Dr Paner). At the time of acceptance, Ms Sood was currently a rotating medical student in the Department of Pathology, University of Chicago Medical Center.
Arch Pathol Lab Med. 2019 Dec;143(12):1562-1567. doi: 10.5858/arpa.2018-0139-RS. Epub 2019 Mar 13.
Plasmacytoid urothelial carcinoma (PUC) is a variant of infiltrating urothelial carcinoma that is characterized by tumor cells that have striking morphologic resemblance to and immunohistochemical overlap with plasma cells, and that harbors mutation. Plasmacytoid urothelial carcinoma can be widely infiltrative and may permeate the urinary bladder in a linitis plastica-like manner and spread along the fascial planes and into the peritoneum. Compared with conventional urothelial carcinoma, PUCs have a greater chance for higher-stage disease, surgical margin positivity, and metastasis at presentation that translate into its poorer outcome. Upstaging of lamina propria-invasive (pT1) tumors diagnosed at transurethral resections is common. Because of its unfavorable behavior, a more aggressive management approach is being recommended for PUC, including consideration for upfront cystectomy in pT1 tumors. Thus, accurate distinction should be made especially on the initial transurethral resection specimens because of the therapeutic and prognostic implications. Awareness of PUC's unique clinical presentation, morphology, and immunohistochemical profile is important to avoid a potential misdiagnosis from its mimics.
浆母细胞性尿路上皮癌（PUC）是浸润性尿路上皮癌的一种变体，其特征是肿瘤细胞具有与浆细胞明显相似的形态学特征和免疫组织化学重叠，并且携带 突变。浆母细胞性尿路上皮癌可能广泛浸润，并可能以类似于皮革样胃炎的方式渗透膀胱，并沿着筋膜平面扩散并进入腹膜。与传统的尿路上皮癌相比，PUC 更有可能发生更高分期的疾病、手术切缘阳性和首发转移，从而导致其预后更差。在经尿道切除术中诊断为固有层浸润性（pT1）肿瘤的分期升级很常见。由于其不良的行为，正在为 PUC 推荐更积极的治疗方法，包括在 pT1 肿瘤中考虑 upfront 膀胱切除术。因此，由于治疗和预后的影响，特别是在初始经尿道切除标本中，应准确区分。了解 PUC 的独特临床表现、形态学和免疫组织化学特征对于避免其类似物的潜在误诊很重要。
