S2341 Malignancy-Associated Pseudoachalasia: An Unusual Cause

Abstract

Introduction: Achalasia is a rare motility disorder characterized by loss of inhibitory neurons of the myenteric plexus in the esophageal wall. Previous retrospective studies have suggested 4% of patients that present with achalasia-like symptoms and radiographic and esophageal manometric findings consistent achalasia will have causes of dysphagia besides primary achalasia, or pseudoachalasia. We describe a case of pseudoachalasia from a rare cause in a patient with dysphagia and weight loss. Case Description/Methods: An 84-year-old female presented with dysphagia for solids more than liquids, regurgitation of food, and 50 lbs weight loss over 6 months. The patient underwent high-resolution esophageal manometry (HREM) that demonstrated a hypertensive lower-esophageal sphincter. HREM also demonstrated failed peristalsis, incomplete bolus clearance, and pan-esophageal pressurization. An upper GI series demonstrated minimal passage of barium into the stomach, with a tapering of the esophagus with a bird beak-like pattern. The patient was referred for POEM for achalasia. At the start of the procedure, the GE junction was noted to be very tight and would not allow passage of the gastroscope. To advance the gastroscope into the stomach, balloon dilation over a guide wire was performed using a through-the-scope balloon. Endoscopic ultrasound (EUS) was then used to further evaluate the tight GE junction. EUS demonstrated heterogeneous thickening of the esophageal wall extending to the GE junction and gastric cardia. Several enlarged lymph nodes were seen adjacent to the infiltrative process. At the GE junction there was a solid, hard hypoechoic lesion that resisted passage of the endoscope. Pathologic and immunohistochemical analysis of a core tissue biopsy demonstrated atypical mesothelial cells suggestive of mesothelioma. Discussion: The epidemiology of pseudoachalasia remains uncertain given it is a rare mimicker of an already rare motility disorder. Malignancy can produce dysphagia through direct compression of the GE junction or due to submucosal invasion and disruption of the myenteric plexus. Especially in elderly patients, those with significant weight loss or a short duration of symptoms, a diagnosis of malignancy-related pseudoachalasia should be considered. As this case showed, all the other diagnostic testing in the workup of achalasia was consistent with achalasia and fooled us into missing an underlying cancer.