背景：尿路上皮癌（MPVUC）的微乳头状变异是罕见且具有侵袭性的。手术标本通常显示具有超色的细胞的非典型微簇（AMC），pynotic,外围,不规则的细胞核与细胞质的比例可变。我们回顾了MPVUC患者的尿路细胞学（UTC），并假设AMC的存在与手术标本中的AMC相似。
方法：从2000年至2020年检索了患有MPVUC或常规高级别尿路上皮癌（HGUC）且先前有异常UTC的手术患者的档案。两名病理学家以盲法检查了UTC病例和对照的AMC，没有定量，低,中度,和高。采用二次加权Cohen的Kappa检验比较了评分者间的可靠性。通过逻辑回归确定数字平均得分与MPVUC状态之间的关联。
结果：5例侵入性MPVUC患者，一名具有非侵入性微乳头成分的患者，包括15例常规HGUC对照患者。所有患者先前或同时具有异常UTC样本。细胞学上AMC数量的增加与微乳头状状态相关（OR7.9，95％CI2.7-118，p=.045），评估者之间有适度的一致性(科恩的Kappa0.54，95%CI0.19-0.89，p=.004)。
结论：在手术标本上患有MPVUC的患者中，在细胞学上经常观察到AMC。在非微乳头状HGUC患者中观察到类似的非典型簇，虽然频率较低。然而,鉴于世卫组织建议仅在存在侵入性微乳头状成分的情况下诊断微乳头状，在UTC上对MPVUC的特定诊断不能仅基于AMC的存在。
BACKGROUND: The micropapillary variant of urothelial carcinoma (MPVUC) is rare and aggressive. Surgical specimens often show atypical micro-clusters (AMCs) of cells with hyperchromatic, pyknotic, peripheral, irregular nuclei with variable nuclear to cytoplasmic ratios. We reviewed urinary tract cytology (UTC) from patients with MPVUC and hypothesized that AMCs would be present similar to those in surgical specimens.
METHODS: The archives were searched from 2000 to 2020 for patients with surgical cases with either MPVUC or conventional high-grade urothelial carcinoma (HGUC) and with prior abnormal UTC. Two pathologists reviewed UTC cases and controls in a blinded manner for AMCs, with quantitation of none, low, moderate, and high. Interrater reliability was compared by quadratic weighted Cohen\'s Kappa test. The association between numerical average score and MPVUC status was determined by logistic regression.
RESULTS: Five patients with invasive MPVUC, one patient with a noninvasive micropapillary component, and 15 control patients with conventional HGUC were included. All patients had prior or concurrent abnormal UTC samples. Increasing category of quantities of AMCs on cytology was associated with micropapillary status (OR 7.9, 95% CI 2.7-118, p = .045), with moderate agreement between raters (Cohen\'s Kappa 0.54, 95% CI 0.19-0.89, p = .004).
CONCLUSIONS: In patients with MPVUC on surgical specimen, AMCs were frequently observed on cytology. Similar atypical clusters were observed in patients with nonmicropapillary HGUC, albeit at lower frequency. However, given the WHO recommendation to diagnose micropapillary only if an invasive micropapillary component is present, a specific diagnosis of MPVUC on UTC cannot be based solely on the presence of AMCs.
