Acute Intestinal Obstruction Caused by Dual‐Component Metastasis From Combined Small Cell Lung Cancer: A Rare Case and Literature Review

This case report describes a 75-year-old male patient who was admitted due to acute intestinal obstruction. The patient had a history of small cell lung cancer. Emergency surgery pathology confirmed the presence of primary composite small cell lung cancer with rare independent dual component metastasis: The colonic lesion was metastatic poorly differentiated adenocarcinoma, and the mesenteric lymph nodes were metastatic small cell carcinoma. Postoperatively, the patient rapidly progressed to septic shock and multiple organ failure, ultimately resulting in death. To our knowledge, this case is the first report of Combined Small Cell Lung Cancer (C-SCLC) presenting a rare pattern of independent dual-component metastasis (adenocarcinoma component metastasizing to the colonic mucosa and small cell carcinoma component metastasizing to the lymph nodes) leading to acute intestinal obstruction. This finding expands the understanding of the metastatic heterogeneity of C-SCLC, suggesting that its different cellular components may possess independent metastatic potential and target organ preferences, reflecting the molecular plasticity of tumors during evolution.