Seronegative End-Stage Type I Achalasia With Megaesophagus in a Middle-Aged Woman From Central America: A Case Report.

Achalasia is a primary esophageal motility disorder defined by impaired lower esophageal sphincter relaxation and absent peristalsis. Late-stage disease can lead to megaesophagus, a severe dilation and tortuosity of the esophageal body. While most cases are idiopathic, secondary achalasia can be caused by Chagas disease (Trypanosoma cruzi infection), an important consideration in patients from endemic regions of Central and South America. Our case highlights a 51-year-old female from Nicaragua who presented to the emergency department with an acute onset of shortness of breath. A computed tomography angiogram (CTA) ruled out a pulmonary embolism but revealed a severely distended esophagus impacted with food contents. A chest radiograph demonstrated cardiac silhouette enlargement and left-base atelectasis. Gastroenterology was consulted, and the patient was admitted. A barium esophagogram revealed a markedly dilated, tortuous esophagus with an abrupt transition point with narrowing of the distal esophagus at the gastroesophageal junction (GEJ), resulting in the characteristic "bird's beak" appearance. High-resolution esophageal manometry confirmed an elevated median integrated relaxation pressure (IRP) and absent contractility, establishing a diagnosis of achalasia. Because the patient emigrated from a Chagas-endemic region, T. cruzi IgG antibody testing was performed twice and returned negative. The patient underwent a successful upper endoscopy with pneumatic balloon dilation of the GEJ. Her respiratory and dysphagia symptoms resolved; she tolerated a regular diet, and she was safely discharged. This case highlights a unique presentation of end-stage achalasia with megaesophagus initially manifesting as acute dyspnea. It underscores the diagnostic imperative to screen for secondary infectious etiologies like Chagas disease in endemic populations, while recognizing the limitations of single-assay serology. Ultimately, idiopathic achalasia remains the most probable diagnosis once pseudoachalasia and mechanical obstructions are excluded via high-resolution esophageal manometry and endoscopy.