LAUSR

Rationale: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Mediastinal GISTs are rare and mostly arise from the esophagus. Patient concerns: A 68-year-old woman with dysphagia who presented with a huge posterior mediastinal mass. Diagnoses: The patient was diagnosed with a GIST through chest computed tomography (CT)-guided core biopsy of the mass. Interventions: Complete excision including the tumor, lower part of the esophagus and fundus of the stomach were performed. Outcomes: On follow-up after 48 months, the patient is currently alive without any evidence of tumor recurrence. Lessons: The case highlights GISTs are taken into consideration in the differential diagnosis of posterior mediastinal masses.