Caustic ingestion represents a medical and surgical emergency capable of causing chemical injury to the gastrointestinal tract, ranging from mucosal erosions to full-thickness necrosis with risk of perforation. Endoscopy is the initial diagnostic tool to assess the extent and depth of injury, often using grading systems such as the Zargar classification to stratify severity and predict complications.

We report the case of a 60-year-old female with a history of caustic ingestion in 2017, which had required partial gastrectomy and duodenectomy due to perforation. She presented again to the Emergency Department following a second episode of caustic ingestion. Urgent gastroscopy revealed extensive necrosis involving the esophageal mucosa, gastric remnant, and intestinal loop, with violaceous nodules and purulent exudate. General surgery was consulted and recommended an urgent exploratory laparotomy, which revealed transmural necrosis extending to the cecum. Due to the severity and extent of the injury, surgical resection was deemed incompatible with life and was not performed.

This case underscores the importance of correlating endoscopic and surgical findings. While endoscopy allows direct assessment of mucosal injury, it may underestimate transmural involvement and deep complications, which are only confirmed surgically. Concordance between both modalities is critical for accurate diagnosis, appropriate therapeutic planning, and optimization of prognosis.