P1.012. Malignant Transformation Within an Epiphrenic Diverticulum in Long-Standing Achalasia: A Very Rare but Preventable Disease Cascade

Topic Benign Disease: Esophageal Function and Motility Background Achalasia is a chronic oesophageal motility disorder causing stasis and inflammation, predisposing to structural complications and malignancy. While squamous cell carcinoma (SCC) is a recognized risk in long-standing disease, malignant transformation within an epiphrenic diverticulum is exceptionally rare. Methods A 74-year-old woman with achalasia diagnosed in 2009 after endoscopy and barium swallow underwent endoscopic dilatations before defaulting follow-up for 15 years. She re-presented with progressive dysphagia, weight loss, and severe malnutrition (BMI 12). Evaluation included repeat upper endoscopy with biopsy and cross-sectional imaging for staging. Assessment demonstrated a moderately differentiated squamous cell carcinoma arising within an epiphrenic diverticulum in a markedly dilated oesophagus, staged cT2N0M0 without distant metastases. Findings were discussed in a multidisciplinary setting to determine optimal management. Results A nasogastric feeding tube was inserted to establish enteral nutrition along with parenteral nutrition in view of her severe malnutrition. The patient was recommended for curative oesophagectomy but she declined and opted for Heller’s cardiomyotomy with Dor fundoplication to relieve obstruction and allow for oral feeding with plans for definitive chemoradiotherapy for treatment of her oesophageal SCC. Conclusion This case illustrates the progressive pathological cascade from untreated achalasia. Chronic stasis and mucosal inflammation likely contributed synergistically to both diverticulum formation and carcinogenesis. It underscores the importance of early diagnosis, timely and appropriate treatment with long-term surveillance in achalasia patients. One should maintain a high index of suspicion for malignancy in such patients presenting with worsening symptoms, even when structural complications (eg. diverticula) are known.