Pulmonary typical carcinoid (TC) is a low‐grade, rare lung cancer of neuroendocrine origin. Currently, there is very little information available about the immune cell composition in TC tumours. Here, we analysed by flow cytometry resected tumours from four never‐smoker female patients with TC. Twelve distinct immune cell types were identified in TC tumours. The most abundant immune cells were CD8⁺ T cells, CD4⁺ T cells, B cells and macrophages, which represented 19.8%, 17.7%, 11.5% and 11% of all tumour‐infiltrating CD45⁺ leucocytes, respectively. Natural killer (NK) cells (8.8%) and neutrophils (3.9%) were also common. Three types of dendritic cells (DCs) were identified (plasmacytoid DCs, CD1c DCs, and CD141 DCs) which together constituted 1.4% of all immune cells in TC tumours. Small populations of basophils (1.2%), mast cells (0.8%) and eosinophils (0.6%) were also present. Notably, the percentage of leucocytes (of all living cells) was much lower in TC tumours compared to high‐grade non‐small cell lung cancer (NSCLC) tumours and also compared to non‐cancerous lung tissue. We conclude that TC tumours are relatively non‐inflammatory, although the immune landscape was found to be very complex.

中文翻译：

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典型类癌性肺肿瘤的免疫微环境，四例简报。

肺部典型类癌（TC）是一种神经内分泌起源的低度罕见肺癌。目前，关于TC肿瘤中免疫细胞组成的信息很少。在这里，我们通过流式细胞仪分析了四名从未吸烟的女性TC患者的切除肿瘤。在TC肿瘤中鉴定出十二种不同的免疫细胞类型。免疫细胞最多的是CD8 ⁺ T细胞，CD4 ⁺ T细胞，B细胞和巨噬细胞，分别占所有肿瘤浸润CD45 ^+的19.8％，17.7％，11.5％和11％。白细胞分别。天然杀伤（NK）细胞（8.8％）和中性粒细胞（3.9％）也很常见。鉴定出三种类型的树突细胞（DC）（浆细胞样DC，CD1c DC和CD141 DC），它们共构成TC肿瘤中所有免疫细胞的1.4％。还存在少量嗜碱性粒细胞（1.2％），肥大细胞（0.8％）和嗜酸性粒细胞（0.6％）。值得注意的是，与高级别非小细胞肺癌（NSCLC）肿瘤以及非癌性肺组织相比，TC肿瘤中（所有活细胞中）白细胞的百分比要低得多。我们得出的结论是，尽管发现免疫情况非常复杂，但TC肿瘤是相对非炎症性的。