A bulging esophageal mucosal lesion is not necessarily cancerous, so you should not be nervous.
The submucosal bulge in the esophagus is just a morphologic change on endoscopy. It may be a tumor in the submucosal tissue of the esophagus, or it may be due to compression by an organ outside the esophageal wall.
Submucosal bulging lesions of the esophagus are generally benign, the majority being smooth muscle tumors and the minority being mesenchymal tumors, isolated venous tumors, neuroendocrine tumors, esophageal polyps, esophageal carcinomas, and metastases.
Esophageal submucosal augmentation lesions, to determine the nature of the lesion, require ultrasound endoscopy as well as biopsy of pathologic tissue. Treatment is usually endoscopic ESD (endoscopic submucosal dissection) or EMR (endoscopic mucosal resection).