Malignancy-Associated Secondary EGJOO (Pseudoachalasia) Due to Infiltrative Gastric Adenocarcinoma

Pseudoachalasia is an uncommon condition that clinically, radiographically, and manometrically mimics primary achalasia and is most frequently caused by a malignancy involving the gastroesophageal junction or gastric cardia. Distinguishing pseudoachalasia from a primary motility disorder remains challenging because conventional investigations may initially appear reassuring. We present a patient with progressive dysphagia and weight loss whose initial EGD was interpreted as showing no definite mucosal abnormality and whose HREM demonstrated a manometric pattern consistent with EGJOO. Progressive symptoms prompted repeat endoscopy and EUS; these revealed distinct abnormalities of the proximal gastric wall; targeted biopsies confirmed poorly differentiated gastric adenocarcinoma. Although the initial endoscopic examination showed no evident abnormality, HREM cannot visualize or histologically characterize tissue; therefore, it cannot exclude a structural or malignant etiology. This case illustrates that progressive symptoms should prompt re-evaluation.