Moyana Terence N
Diagnostic and Molecular Pathology, The Ottawa Hospital and University of Ottawa, Ottawa K1H 8L6, Ontario, Canada.
World J Gastroenterol. 2024 Dec 28;30(48):5198-5204. doi: 10.3748/wjg.v30.i48.5198.
Small cell lung carcinoma metastatic to the stomach, whether synchronous or metachronous, is a rare phenomenon accounting for < 0.5% of lung cancers. Hence it can be overlooked by clinicians resulting in delayed diagnosis. This manuscript comments on Yang 's article which reported 3 such cases. The main diagnostic features are based on routine morphology comprised of small cells with hyperchromatic nuclei, scant cytoplasm, brisk mitoses and necrosis. This can be supplemented by immunohistochemistry demonstrating positivity for cytokeratin, thyroid transcription factor-1 and neuroendocrine markers as well as a high Ki-67 labelling index. Imaging modalities such as positron emission tomography/contrast computed tomography help to confirm lung origin and rule out the possibility of extra-pulmonary small cell carcinoma. The predominant mechanism of spread is most likely hematogeneous. Prognosis is generally poor since this represents stage 4 disease but survival can be improved by chemo/radiotherapy and palliative surgery in select cases. Though outcomes have not changed much in the last several decades, the recent Food and Drug Administration approval of immune checkpoint inhibitors was a significant milestone as was the delineation of small cell lung carcinoma molecular subtypes. Liquid biopsies are increasingly being used for biomarker studies in clinical trials to assess treatment response and prognosis.
小细胞肺癌转移至胃，无论是同时性还是异时性转移，都是一种罕见现象，占肺癌的比例不到0.5%。因此，临床医生可能会忽视它，导致诊断延迟。本文对Yang报道3例此类病例的文章进行评论。主要诊断特征基于常规形态学，包括细胞核深染、胞质稀少、有丝分裂活跃和坏死的小细胞。免疫组织化学显示细胞角蛋白、甲状腺转录因子-1和神经内分泌标志物呈阳性，以及高Ki-67标记指数可作为补充。正电子发射断层扫描/对比计算机断层扫描等成像方式有助于确认肺部起源，并排除肺外小细胞癌的可能性。主要的转移机制很可能是血行转移。由于这代表IV期疾病，预后通常较差，但在某些病例中，化疗/放疗和姑息性手术可改善生存率。尽管在过去几十年中结果变化不大，但最近美国食品药品监督管理局批准免疫检查点抑制剂是一个重要的里程碑，小细胞肺癌分子亚型的划分也是如此。液体活检越来越多地用于临床试验中的生物标志物研究，以评估治疗反应和预后。
