Abstract
Carcinosarcoma of the stomach is a rare neoplasm, and a total of 61 cases have been reported from 1950. We experienced a case of gastric carcinosarcoma arisen after local resection of the stomach for early gastric cancer (GC). The patient was a 78-year-old man, who underwent local resection for three early GCs at the age of 74. Pathologically, all lesions were intramucosal adenocarcinoma and the surgical margins were all negative, but lymphatic vessel invasion was detected in one lesion which resected up to the depth of muscle layer. The patient stopped attending our hospital after the operation in his own judgement. Three years and 8 months after the local gastric resection, an abdominal CT scan performed in other hospital showed a suspicion of recurrence of GC, and he consulted us for further investigation. A gastric tumor was detected in the upper gastric corpus, where was just the same site that the former resection with muscular layer had been performed. Result of biopsy was non-epithelial malignancy. The patient underwent total gastrectomy. Pathologically, the central part of the tumor consisted of sarcoma and the surroundings, adenocarcinoma, then carcinosarcoma (CS) was diagnosed. So far six cases of CS arisen in the operated stomach have been reported. This is the first case of CS arisen in the lesion which had been locally resected at the former operation. Histogenesis of carcinosarcoma in the present case was considered to lie in dedifferentiation of adenocarcinoma from the clinical course.
