Abstract
Primary lung signet-ring cell carcinomas are a rare entity and only a few cases of pure signet-ring cell carcinomas of the lung are reported in the English literature. They usually have an aggressive behavior and a poor prognosis because in most cases they are identified at an advanced stage. We present a unique case of primary signet-ring cell carcinoma of the lung because the patient was HIV positive, a heavy smoker, and also the tumor, discovered incidentally during chest x-ray, was a pure type of signet-ring cell carcinoma. Surgical therapy associated with chemoradiotherapy represents the gold standard in the care of these patients.