How to diagnose small cell lung cancer

Patients with small cell lung cancer suffer a lot after the onset of the disease, and their families are also under great financial and mental pressure. Small cell lung cancer is a disease that does seriously affect our physical health, so we must actively treat it. There are still many lung cancer patients in life. Today we will talk about how to diagnose small cell lung cancer.

It is generally believed that small cell lung cancer originates from Kulchitsky cells (argentophilic cells) in the bronchial mucosa or glandular epithelium and belongs to APUD (amine precursor uptake decarboxylation) tumors. Some people also believe that it originates from stem cells in the bronchial mucosal epithelium that can differentiate into neuroendocrine. Small cell lung cancer is the least differentiated and most malignant type of lung cancer. It often occurs in the central part of the lung, grows rapidly, and metastasizes early. Under a light microscope, the cancer cells are small and short spindle-shaped or lymphocyte-like, with little cytoplasm and a naked nucleus. The cancer cells are densely arranged in groups, separated by connective tissue, and sometimes the cancer cells are arranged in groups around small blood vessels. Electron microscopic observation of ultrastructure shows that the tumor cell cytoplasm contains typical axon-like neuroendocrine granules, but the amount of granules varies, and it has been proven to be related to 5-HT and ACTH. From the immunohistochemical study, the tumor cells are positive for NSE, 5-HT, CgA, and some cases (10+) are positive for Sy, proving that small cell carcinoma has neuroendocrine function. In addition, positive immunohistochemical reactions for CK and EMA were simultaneously found in the same tumor.

In the past few decades, there have been many studies on the molecular mechanism of SCLC, suggesting that the occurrence of SCLC may involve the participation of multiple genes. Some studies have shown that the tumor suppressor gene p53, RB gene (neuroblastoma gene), oncogene Bcl-2 gene, Myc gene, PI3K/AKT/mTOR signal transduction pathway, etc. are all related to the occurrence of SCLC.

1. Bronchoscopy

Bronchoscopy is an important diagnostic method for small cell lung cancer. Through bronchoscope, the pathological changes of the bronchial lining and lumen can be directly observed. If cancer or cancerous infiltration is observed, tissue can be taken for pathological section examination, or bronchial secretions can be aspirated for cytological examination to confirm the diagnosis and determine the histological type.

2. Radionuclide examination

Radioactive drugs such as 67Ga-citrate have affinity for lung cancer and its metastatic lesions. After intravenous injection, they can be concentrated in the tumor and can be used for the diagnosis of lung cancer to show the extent of the cancer. The positive rate can reach about 90%.

3. X-ray examination

X-ray examination is the most commonly used method for diagnosing small cell lung cancer. X-ray examination can be used to understand the location and size of lung cancer. Although X-ray examination of early lung cancer cases cannot yet show a mass, it may show local emphysema, atelectasis caused by bronchial obstruction, or infiltrative lesions or pulmonary inflammation in the vicinity of the lesion.

Above we have talked about how to diagnose small cell lung cancer. I hope it will be helpful to everyone.