A case of esophageal carcinosarcoma, which proliferated after radical radiochemotherapy for superficial esophageal carcinoma

A 74-year-old man, who was given a diagnosis of esophageal cancer (T1bN0M0 stage I) and was successfully treated by radical radiochemotherapy (60Gy, 5-FU/Cisplatin) in 1998, achieved complete response. In 2004, a nodular lesion was recognized at the same site. and it was found to be atypical epithelium by biopsy. In 2009, the nodular lesion was atypical epithelium on a biopsy, but at the anal side of this lesion there was an area unstained by the spray dye technique, so it was diagnosed as squamous cell carcinoma. This area was close to the nodular lesion, so it was suspected that the carcinoma had progressed submucosally. Esophagestomy and 2-field lymph node dissection was performed. The pathological examination showed esophageal carcinosarcoma, mp, ly0, v0, and the dysplastic spindle cells proliferated close to the SCC. There was no recurrence after 12 months. Only one case of esophageal carcinosarcoma after chemoradiotherapy has been reported in our country. This case in which proliferation occurred after a long interval from the first treatment is very rare. We report this case referring to the mechanism of its origin and the histopathological manifestations.