Two unusual cases of combined lung carcinoma are presented. Both patients, aged 50 and 53 years, had strong histories of cigarette smoking and presented with lung masses. Microscopic examination revealed an uncommon combination of primary lung cancers. Both cases had a dominant histological picture of large cell neuroendocrine carcinoma. The first case was combined with both squamous and small cell carcinomas in almost equal proportions, while the second consisted of large cell neuroendocrine and squamous carcinomas with a focal area of small cell carcinoma. In addition, both cases contained rhabdoid cells. One of the cases pursued an aggressive clinical course with death in 6 months. The other patient presented with recurrent tumor 12 months after the operation and died shortly thereafter. These cases illustrate two examples of uncommon combined lung cancers: large cell neuroendocrine carcinoma combined with squamous carcinoma and small cell carcinoma. An additional feature was the presence of rhabdoid cells in both cases. It is felt that the rhabdoid component is a reflection of de-differentiation or poor differentiation, and may contribute to the aggressive nature of both tumors.