Small-cell lung carcinoma is the most aggressive among lung cancer subtypes, has a poor prognosis and is highly associated with smoking. We present a case of small‑cell lung carcinoma in a patient who had never smoked and has survived for 14 years without achieving a complete remission since the first relapse. His long-term survival may be ascribed to the slow growth of the cancer cells, limited metastasis and favorable responses to the treatments he has received. During these 14 years, only two lymph node metastases and a single metastasis to the brain developed. His small-cell lung carcinoma has been well controlled each time by the various treatments he has received, including chemotherapy, radiotherapy and surgery. Pathologically, the tumor was a typical small-cell lung carcinoma with extensive necrosis. Results showed the mitotic rate and the cell proliferation markers to be greater than those in the intermediate-grade atypical carcinoid, but relatively low. Thus, we conclude that this case belongs to an overlap between intermediate- and high-grade neuroendocrine tumors.