RESUMEN
Double primary cancer means that more than two cancers with different origin exist independently in an individual. The diagnosis of double primary cancer was determined by following criteria. Each of the tumors must present a definite picture of malignancy, each must be distance, and the probability of one being a metastasis of the other must be excluded. Primary small cell carcinoma in the esophagus is relatively rare, and rarer when it is combined with other malignant disease. A review of the Korean medical literature failed to reveal any previously described the case of syn-chronous double primary cancer of primary esophageal small cell carcinoma and squamous cell carcinoma of lung. Recently, we have experienced a case of double primary cancer, a 65-year-old man with primary esophageal small cell carcinoma and squamous cell carcinoma of lung, which were diagnosed by endoscopic biopsy and bronchoscopic biopsy.