Case report: Black esophagus. Research, Society and Development, [S. l.], v. 14, n. 9, p. e5214949535, 2025. DOI: 10.33448/rsd-v14i9.49535. Disponível em: https://rsdjournal.org/rsd/article/view/49535. Acesso em: 5 dec. 2025.