The esophagus can be divided into thirds: top (proximal) or neck, middle or chest, and lower or abdominal. Esophageal cancer consists of mucous membrane cancer or adenocarcinomas most commonly, or squamous cell or epidermoid cancers. Adenocarcinomas can arise from pre-cancerous cells caused by heartburn or GERD.
Mesothelioma, or malignant mesothelioma, is a rare kind of cancer. It starts in the mesothelium, a thin lining that protects the outer surface of some organs, including the lungs, stomach/abdominal space and chest wall.
A thymoma is a tumor in the thymus gland. It is a rare, typically nonaggressive cancer that is occasionally found among people who have the autoimmune disease myasthenia gravis.