Pathology and Laboratory Medicine, University of British Columbia and Vancouver General Hospital, Vancouver, British Columbia, Canada.
Department of Clinical Pathology, Pamela Youde Nethersole Eastern Hospital, Hong Kong, China.
Mod Pathol. 2023 Feb;36(2):100010. doi: 10.1016/j.modpat.2022.100010. Epub 2023 Jan 9.
Abnormal p53 (p53abn) immunohistochemical (IHC) staining patterns can be found in vulvar squamous cell carcinoma (VSCC) and differentiated vulvar intraepithelial neoplasia (dVIN). They can also be found in the adjacent skin that shows morphology that falls short of the traditional diagnostic threshold for dVIN. Vulvectomy specimens containing human papillomavirus-independent p53abn VSCC with margins originally reported as negative for invasive and in situ disease were identified. Sections showing the closest approach by invasive or in situ neoplasia to margins were stained with p53 IHC stains. We evaluated the following: (1) detection of morphologically occult p53abn in situ neoplasia, (2) rates of margin status change after p53 IHC staining, and (3) effect of p53abn IHC staining at margins on the 2-year local recurrence rates. Seventy-three human papillomavirus-independent p53abn VSCCs were included. Half (35/73, 48%) had documented an in situ lesion in the original report. The use of p53 IHC staining identified 21 additional cases (29%) with the p53abn in situ lesions that were originally unrecognized. The histology of in situ lesions in the p53abn "field" varied and became more subtle (morphologically occult) farther away from the VSCC. Fifteen (21%) cases had a morphologically occult and previously unrecognized p53abn in situ lesion present at a resection margin, which conferred an increased risk of local recurrence (5/7 [71.4%] vs 6/22 [27.3%], P = .036). The p53abn in situ lesions at a margin were confirmed to have TP53 mutations by sequencing. p53 IHC staining identified morphologically occult p53abn in situ lesions surrounding human papillomavirus-independent VSCC. p53abn IHC staining at a margin was associated with a 3-fold increased risk of local recurrence.
p53（p53abn）免疫组织化学（IHC）染色模式可在外阴鳞状细胞癌（VSCC）和分化的外阴上皮内瘤变（dVIN）中发现。它们也可在外阴皮肤中发现，这些皮肤的形态不符合传统的 dVIN 诊断阈值。识别出包含 HPV 独立的 p53abn VSCC 的外阴切除术标本，这些标本的边缘最初报告为浸润性和原位疾病阴性。显示侵袭性或原位肿瘤最接近边缘的切片用 p53 IHC 染色剂染色。我们评估了以下内容：（1）检测形态学隐匿性的 p53abn 原位肿瘤，（2）p53 IHC 染色后边缘状态变化的发生率，以及（3）p53abn IHC 染色在边缘对 2 年局部复发率的影响。共纳入 73 例 HPV 独立的 p53abn VSCC。半数（35/73，48%）在原始报告中记录有原位病变。使用 p53 IHC 染色鉴定出另外 21 例（29%）存在 p53abn 原位病变，这些病变在原始报告中未被识别。p53abn“场”中的原位病变的组织学变化更加微妙（形态学隐匿），距离 VSCC 越远。15 例（21%）患者的切缘存在形态学隐匿且以前未被识别的 p53abn 原位病变，这增加了局部复发的风险（7/7 [71.4%] 与 6/22 [27.3%]，P=0.036）。通过测序证实，边缘的 p53abn 原位病变存在 TP53 突变。p53 IHC 染色鉴定出 HPV 独立的 VSCC 周围形态学隐匿的 p53abn 原位病变。边缘的 p53abn IHC 染色与局部复发风险增加 3 倍相关。
