Metachronous Squamous Cell Carcinoma of the Esophagus After Resolution of Previous Adenocarcinoma.

Esophageal cancer is the sixth leading cause of cancer-related death worldwide. Metachronous malignancies refer to multiple independent primary cancers diagnosed at least 6 months apart. The incidence of metachronous esophageal cancers with different histologic subtypes is extremely rare. This case presents an unprecedented occurrence of esophageal adenocarcinoma, followed by metachronous squamous cell carcinoma.