A distinctive histological variant of poorly differentiated, sarcomatoid, non-small cell lung carcinoma characterized by a discohesive population of giant tumor cells associated with prominent interstitial inflammatory cell infiltrates is described. The tumors occurred in 7 women and 7 men, 42 to 72 years of age (mean: 56 y). They predominantly affected the upper lobes and measured 1.3 to 9 cm in greatest diameter (mean: 4.6 cm). The tumor cells were characterized by large pleomorphic nuclei with prominent nucleoli, ample cytoplasm, and frequent abnormal mitoses, and were surrounded by a dense inflammatory cell infiltrate, often associated with emperipolesis. Immunohistochemical stains were positive in the tumor cells for cytokeratin AE1/AE3 and CK8/18 and negative for TTF1, napsin A, p40, and CK5/6. Next-generation sequencing was performed in all cases using the Oncomine Precision Assay; the most common abnormalities found included TP53 mutations (9 cases) and AKT1 amplification (8 cases), followed by KRAS mutations (4 cases) and MAP2K1/2 mutations (4 cases). Clinical follow-up was available in 13 patients. Three patients presented with metastases as the initial manifestation of disease; 8 patients died of their tumors from 6 months to 8 years (mean: 2.7 y); 3 patients were alive and well from 4 to 6 years; and 2 patients had metastases when last seen but were lost to follow-up thereafter. The importance of recognizing this distinctive and aggressive variant of non-small cell lung carcinoma lies in avoiding confusion with a sarcoma or other types of malignancy.

中文翻译：

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肺炎性巨细胞癌：14 例临床病理学、免疫组织化学和下一代测序研究。


描述了低分化肉瘤样非小细胞肺癌的一种独特的组织学变异，其特征是与显着的间质炎症细胞浸润相关的巨肿瘤细胞的不粘性群体。肿瘤发生于 7 名女性和 7 名男性，年龄 42 至 72 岁（平均 56 岁）。它们主要影响上叶，最大直径为 1.3 至 9 厘米（平均：4.6 厘米）。肿瘤细胞的特点是大的多形性细胞核，核仁突出，细胞质丰富，经常出现异常的有丝分裂，周围有致密的炎性细胞浸润，通常与穿入有关。肿瘤细胞的细胞角蛋白 AE1/AE3 和 CK8/18 免疫组织化学染色呈阳性，TTF1、napsin A、p40 和 CK5/6 呈阴性。所有病例均使用 Oncomine Precision Assay 进行新一代测序；最常见的异常包括TP53突变（9例）和AKT1扩增（8例），其次是KRAS突变（4例）和MAP2K1/2突变（4例）。 13 名患者进行了临床随访。 3名患者以转移为疾病的首发表现； 8名患者在6个月至8年期间死于肿瘤（平均：2.7岁）； 3名患者存活4至6年，状态良好； 2 名患者最后一次就诊时已出现转移，但此后失访。认识非小细胞肺癌这种独特且具有侵袭性的变体的重要性在于避免与肉瘤或其他类型的恶性肿瘤混淆。