Female patient, 47 years old, from Belo Horizonte. Two years ago began with intense retrosternal pain on swallowing. Last year progressed with dysphagia, heartburn, regurgitation and involuntary 50kg weight loss. Sedentary, obese class III without other comorbidities. An esophagogram with barium sulfate was done.

Question:
Based on clinical and radiological findings, which is the most likely diagnosis?