Han Yeo Eun, Sung Deuk Jae, Cho Hyun Yee, Yang Kyung Sook, Park Jae Wook, Sim Ki Choon, Han Na Yeon, Park Beom Jin, Kim Min Ju
Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea.
Department of Pathology, Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea.
Korean J Radiol. 2025 Sep;26(9):832-840. doi: 10.3348/kjr.2025.0419.
Plasmacytoid urothelial carcinoma (PUC) is a rare aggressive bladder cancer subtype with limited imaging data owing to its low incidence. This study aimed to report the characteristic features of PUC on multiparametric MRI (mpMRI).
We retrospectively analyzed 13 patients with histologically confirmed PUC who underwent preoperative mpMRI between January 2019 and August 2024. Two blinded radiologists independently assessed tumor size, morphology, signal intensity, apparent diffusion coefficient (ADC) values, dynamic contrast enhancement patterns, contrast enhancement features, and invasive characteristics. Vesical imaging-reporting and data system (VI-RADS) scores were recorded. Interobserver agreement was evaluated using the kappa statistic.
PUC predominantly exhibited diffuse (6/13, 46.2%) or localized (5/13, 38.5%) bladder wall thickening. Diffuse thickening was often associated with a linitis plastica-like appearance. On high b-value diffusion-weighted imaging (DWI), eight and seven cases depending on readers (61.5% and 53.8%, respectively) showed mild hyperintensity or isointensity, with a mean ADC value of 1.1 × 10⁻³ mm²/s. Dynamic contrast-enhanced MRI revealed progressive and prolonged enhancement in 10 cases (76.9%). VI-RADS scores ≥ 4 were observed in 11 cases (84.6%). Histopathological analysis showed that tumors with progressive and prolonged enhancement contained myxoid stroma and some fibrous tissue. Interobserver agreement was excellent for most imaging features, except for good agreement on DWI signal intensity.
PUC demonstrates notable mpMRI features, including localized or diffuse wall thickening (often with a linitis plastica-like appearance), muscle-invasive and advanced disease, progressive and prolonged enhancement patterns, and mild hyperintensity or isointensity on high b-value DWI. These features, which are potentially linked to the myxoid stromal composition of the tumor, suggest that mpMRI may serve as a noninvasive diagnostic tool for this aggressive malignancy. However, further studies with larger cohorts are required to confirm these findings.
浆细胞样尿路上皮癌（PUC）是一种罕见的侵袭性膀胱癌亚型，因其发病率低，影像学数据有限。本研究旨在报告PUC在多参数磁共振成像（mpMRI）上的特征。
我们回顾性分析了2019年1月至2024年8月期间13例经组织学证实为PUC且术前行mpMRI检查的患者。两名盲法放射科医生独立评估肿瘤大小、形态、信号强度、表观扩散系数（ADC）值、动态对比增强模式、对比增强特征和侵袭特征。记录膀胱影像报告和数据系统（VI-RADS）评分。使用kappa统计量评估观察者间的一致性。
PUC主要表现为弥漫性（6/13，46.2%）或局限性（5/13，38.5%）膀胱壁增厚。弥漫性增厚常伴有皮革胃样外观。在高b值扩散加权成像（DWI）上，根据阅片者不同，分别有8例（61.5%）和7例（53.8%）表现为轻度高信号或等信号，平均ADC值为1.1×10⁻³mm²/s。动态对比增强MRI显示10例（76.9%）呈渐进性和持续性增强。11例（84.6%）VI-RADS评分≥4。组织病理学分析显示，具有渐进性和持续性增强的肿瘤含有黏液样基质和一些纤维组织。除DWI信号强度一致性良好外，大多数影像特征观察者间一致性极佳。
PUC在mpMRI上表现出显著特征，包括局限性或弥漫性壁增厚（常伴有皮革胃样外观）、肌层浸润性和晚期疾病、渐进性和持续性增强模式以及高b值DWI上的轻度高信号或等信号。这些特征可能与肿瘤的黏液样基质成分有关，提示mpMRI可能作为这种侵袭性恶性肿瘤的非侵入性诊断工具。然而，需要更大样本量的进一步研究来证实这些发现。
