LAUSR

Background Esophageal squamous cell carcinoma (ESCC) and leiomyoma are common tumors. The coexistence of these two tumors can be classified into two types: the overlying type and the separate type. The overlying type is rare. Methods We report 12 cases of the overlying type treated by endoscopic submucosal dissection (ESD). They underwent pre-ESD endoscopic examination with white-light imaging, iodine staining, narrow-band imaging, endoscopic ultrasound, and biopsy. The clinical, endoscopic and pathologic characteristics were reviewed. Results Among the 12 patients, 3 were female and 9 were male. The age range was 49–76 years. They accounted for 4.0% of 300 cases of esophageal leiomyoma and 1.3% of 955 cases of superficial ESCC or high-grade dysplasia treated by endoscopic resection. After endoscopic examination and biopsy, ESCC or high-grade dysplasia, combined with leiomyoma was considered in four cases; leiomyoma was considered but without the squamous lesion (underdiagnosis) in another case; and leiomyoma was mistaken for submucosal ESCC (overdiagnosis) in the other seven cases. ESD specimens showed that nine cases were intramucosal or submucosal ESCC, and three cases were high-grade dysplasia, overlying leiomyoma originating from the muscularis mucosae or muscularis propria. The 12 cases were successfully treated by ESD, with no recurrence during follow-up. Conclusions We must keep in mind that ESCC or high-grade dysplasia can occur overlying leiomyoma. These cases are rare but should not be neglected, especially in high-risk areas for ESCC. These patients can receive appropriate treatment if overdiagnosis or underdiagnosis can be avoided.