Combined large‑cell neuroendocrine carcinoma and small‑cell lung cancer: A case report.

Combined large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung cancer (SCLC) is extremely rare, with only a few reports available in the literature. An accurate diagnosis is difficult to make due to the overlapping clinical features between LCNEC and SCLC, and a standardized treatment option is lacking. A 53-year-old female patient was admitted to Xiaoshan Affiliated Hospital of Wenzhou Medical University (Hangzhou, China) due to symptoms of dyspnea and phlegm, with blood in the sputum. Computed tomography revealed a 52×32×26-mm irregular soft-tissue mass in the left upper lung. Pathological examination of the biopsy specimen showed a poorly differentiated neuroendocrine carcinoma with compression injury, consistent with a mixed type of large and small cell carcinoma. The patient was administered chemotherapy, radiotherapy and targeted therapy, and as of October 2023, the patient had a survival period of 29 months. LCNEC combined with SCLC is a sporadic tumor with a high potential for malignancy. Multidisciplinary treatment and close follow-up are recommended. The multidisciplinary treatment strategy used in the present study is expected to help inform future therapeutic decisions.