[A case of superficial esophageal basaloid squamous cell carcinoma resected by endoscopic submucosal dissection].

A woman in her 70s visited our hospital to undergo endoscopy. Esophagogastroduodenoscopy showed a white submucosal tumor-like lesion in the upper esophagus. Analysis of a biopsy specimen revealed that the tumor was a basaloid squamous cell carcinoma. A superficial squamous cell carcinoma was also revealed near the basaloid squamous cell carcinoma before endoscopic submucosal dissection. Curative en bloc resection was successfully performed. Histopathological examination revealed that the basaloid and superficial squamous cell carcinomas had invaded the lamina propria (pT1a-LPM) and epithelium (pT1a-EP), respectively. In addition, the basaloid squamous cell carcinoma had two different components in terms of malignancy and differentiation. Here we report a rare case of esophageal basaloid squamous cell carcinoma resected by endoscopic submucosal dissection.