胰岛素瘤相关蛋白 1 在细胞学涂片诊断小细胞肺癌中是一种强有力的核免疫染色。

Insulinoma-associated protein 1 is a robust nuclear immunostain for the diagnosis of small cell lung carcinoma in cytology smears.

机构信息

Department of Pathology, All India Institute of Medical Sciences, New Delhi, India.

出版信息

Cancer Cytopathol. 2019 Aug;127(8):539-548. doi: 10.1002/cncy.22164. Epub 2019 Jul 25.

DOI:10.1002/cncy.22164

PMID:31343851

Abstract

BACKGROUND

In a significant percentage of patients with small cell lung carcinoma (SCLC), cytology samples represent the only source of tumor tissue. Ancillary immunocytochemistry (ICC) for neuroendocrine markers is an important adjunct for the diagnosis of SCLC. Insulinoma-associated protein 1 (INSM1) is a novel neuroendocrine marker proposed as an economical single-marker alternative to the traditional 3-marker panel of chromogranin, synaptophysin, and CD56. To the authors' knowledge, limited studies have evaluated INSM1 immunohistochemistry (IHC) for the diagnosis of SCLC and reported high sensitivities and specificities. The objective of the current study was to evaluate the sensitivity and specificity of INSM1 ICC on direct smears (DS) from patients with SCLC in comparison with IHC on small biopsies (SBs).

METHODS

All available DS and SBs from patients with SCLC who were diagnosed over the previous year were retrieved. Immunostaining for INSM1 was performed on alcohol-fixed DS and formalin-fixed SBs wherever available. A total of 10 DS and SBs from patients with non-small cell lung carcinoma were included for comparison. Nuclear staining for INSM1 in ≥1% tumor cells was interpreted as positive.

RESULTS

Among a total of 60 patients with SCLC who were included in the current study, a total of 37 underwent INSM1 IHC on SBs and 36 underwent INSM1 ICC on DS. ICC was noninterpretable in 3 DS due to necrosis. The sensitivity of INSM1 IHC was 97% (36 of 37 cases) whereas the sensitivity of INSM1 ICC was 91% (30 of 33 cases) for the diagnosis of SCLC. Among matched IHC and ICC results available for 11 patients, 91% of cases (10 of 11 patients) demonstrated concordant IHC-ICC staining. All cases of non-small cell lung carcinoma were negative for INSM1 (100% specificity).

CONCLUSIONS

INSM1 appears to be a robust and reliable ICC marker for the confirmation of SCLC diagnosis on cytology smears.

摘要

背景

在相当大比例的小细胞肺癌（SCLC）患者中，细胞学样本是肿瘤组织的唯一来源。辅助免疫细胞化学（ICC）检测神经内分泌标志物是诊断 SCLC 的重要辅助手段。胰岛素瘤相关蛋白 1（INSM1）是一种新型神经内分泌标志物，被提议作为传统 3 标志物（嗜铬粒蛋白、突触素和 CD56）的经济单标志物替代物。据作者所知，有限的研究评估了 INSM1 的免疫细胞化学（IHC）在诊断 SCLC 中的应用，并报告了较高的敏感性和特异性。本研究的目的是评估 INSM1 ICC 在 SCLC 患者直接涂片（DS）中的敏感性和特异性，并与小活检（SB）中的 IHC 进行比较。

方法

回顾性分析了过去一年中诊断为 SCLC 的所有患者的可用 DS 和 SB。凡有条件者，均对酒精固定的 DS 和福尔马林固定的 SB 进行 INSM1 免疫染色。共纳入 10 例非小细胞肺癌患者的 DS 和 SB 作为对照。INSM1 在肿瘤细胞中≥1%的核染色为阳性。

结果

本研究共纳入 60 例 SCLC 患者，其中 37 例行 SB 上的 INSM1 IHC，36 例行 DS 上的 INSM1 ICC。由于坏死，3 例 DS 的 ICC 无法解释。INSM1 IHC 的敏感性为 97%（36/37 例），而 INSM1 ICC 的敏感性为 91%（30/33 例），用于诊断 SCLC。在 11 例可获得匹配的 IHC 和 ICC 结果的患者中，91%（11 例中有 10 例）的病例显示出一致的 IHC-ICC 染色。所有非小细胞肺癌病例均为 INSM1 阴性（特异性 100%）。