Some cases of small cell carcinoma show a minor component of either squamous cell carcinoma or adenocarcinoma. They are referred to as combined small cell carcinoma. Uncommonly, the additional component may be large cell carcinoma, spindle cell carcinoma, or giant cell carcinoma. It accounts for only 1-3% of cases. The image shows clusters of macrophages containing anthracotic pigment within the stroma of a small cell lung carcinoma.