Esophageal squamous cell carcinoma or high-grade dysplasia overlying leiomyoma, rare but not to be neglected.

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.