Cervical esophageal pain (worse when swallowing), normal hr & bp, temp 99.5 after egd with biopsies and dilation for 48 hrs post-procedure. no blood in stool, vomiting, or significant chest pain. should i be concerned about a perforation?

Those symptoms are not rare after an esophageal dilatation and biopsy. The esophagus wall is quite thick so perforation with biopsy or dilatation is rare. Mediastinal pain (pain in your chest behind the breast bone and high fever are the symptoms of esophageal perforation and mediastinitis, not bloody vomit or stool. Keep monitor your temperature for now and eating bland diet.