Presence of microsatellite instability in esophageal squamous cell carcinoma associated with chagasic megaesophagus

AIM: The molecular pathogenesis of esophageal squamous cell carcinoma (ESCC) has been increasingly studied, but there is no report on the role of MSI in ESCC development associated with chagasic megaesophagus (CM).Results/methodology: In four ESCC/CM (4/19) we found microsatellite instability (MSI) alterations (21.1%), being three MSI-L (15.8%) and one MSI-H (5.3%). Four out of 35 ESCC cases showed MSI-L (11.4%) and only one out of 26 CM cases presented MSI-L (3.9%). The MSI-H was observed in an ESCC/CM patient that presents lack of MSH6 immunostaining corroborating deficiency in MMR pathway. Interestingly, the MSI-H ESCC/CM case also presented a deletion the HSP110 poly(T)17 gene. DISCUSSION/CONCLUSION: Taking together, we concluded that MSI is a rare event in esophageal squamous cell carcinoma, but can be associated with CM.