识别非侵入性生长模式对于切除的非小细胞肺癌的正确诊断、侵入性大小确定和 pT 分期是必要的。由于切除后医源性塌陷，原位腺癌（AIS）和侵袭性腺癌之间的区分可能很困难。本研究的目的是研究医源性塌陷切除标本中 AIS 非粘液非侵入模式的复杂形态，并将其与随访联系起来。在数学模型中模拟了医源性塌陷对塌陷 AIS 形态的影响。在两个独立的原发性肺腺癌≤3cm切除样本的回顾性队列中，在修改后的分类中应用三维相关标准，还使用细胞角蛋白7和弹性蛋白作为附加染色剂，并提供可用的随访信息。该模型表明，与塌陷程度较低的区域相比，医源性塌陷期间会发生肺泡壁的内皱，并导致最大塌陷区域的肿瘤细胞高度显着增加。根据 WHO 分类，内折叠 AIS 的形态与乳头状和腺泡腺癌的模式重叠，因此需要进行调整。修改后的分类纳入了对医源性和生物性塌陷的识别、切向切割效应的真实侵袭和侵袭的替代标记，即灰色区域，覆盖了微乳头状、筛状和实性肺泡充盈生长的多层结构。弹性蛋白和 CK7 染色的使用有助于形态学识别医源性塌陷 AIS 以及与侵袭性腺癌的区别。在总共 70 例切除标本中，1 例最初被分类为 AIS，9 例被重新分类为医源性塌陷 AIS。平均随访 69.5 个月后，AIS 塌陷患者的无复发生存率为 100%。根据目前的 WHO 分类，AIS 由于内折叠而被过度诊断为侵袭性腺癌。修改后的分类有助于 AIS 的诊断。版权所有 © 2024。由 Elsevier B.V. 出版。

Recognizing non-invasive growth patterns is necessary for correct diagnosis, invasive size determination and pT-stage in resected non-small cell lung carcinoma. Due to iatrogenic collapse after resection, the distinction between adenocarcinoma in-situ (AIS) and invasive adenocarcinoma may be difficult. The aim of this study is to investigate the complex morphology of non-mucinous non-invasive patterns of AIS in resection specimen with iatrogenic collapse, and to relate this to follow-up. The effects of iatrogenic collapse on the morphology of collapsed AIS were simulated in a mathematical model. Three dimensional related criteria applied in a modified classification, using also cytokeratin 7 and elastin as additional stains, in two independent retrospective cohorts of primary pulmonary adenocarcinomas ≤3 cm resection specimen with available follow-up information. The model demonstrated that infolding of alveolar walls occurs during iatrogenic collapse and lead to a significant increase in tumor cell heights in maximal collapse areas, compared to less collapsed areas. The morphology of infolded AIS overlaps with patterns described as papillary and acinar adenocarcinoma according to the WHO classification, necessitating an adaptation. The modified classification incorporates recognition of iatrogenic and biologic collapse, tangential cutting effect true invasion and surrogate markers of invasion i.e. grey zone, covering a multilayering falling short of micropapillary, cribriform and solid alveolar filling growth. The use of elastin and CK7 staining aids in the morphologic recognition of iatrogenic collapsed AIS and the distinction from invasive adenocarcinoma. Out of a total of 70 resection specimens 1 case was originally classified as AIS and 9 were reclassified as iatrogenic collapsed AIS. Patients with collapsed AIS showed a 100 % recurrence-free survival after a mean follow-up time of 69.5 months. With the current WHO classification, AIS is overdiagnosed as invasive adenocarcinoma due to infolding. The modified classification facilitates the diagnosis of AIS.Copyright © 2024. Published by Elsevier B.V.