Primary gastric squamous cell carcinoma presenting as a large submucosal mass: A case report and literature review

RATIONALE: Primary gastric squamous cell carcinoma (SCC) is rarely encountered clinically. SCC, which presents as a submucosal tumor, is even rarer. Without the support of pathological evidence, it is difficult to make a correct preoperative diagnosis. Due to limited clinical data, the pathogenesis and treatment of gastric SCC remain unclear. PATIENT CONCERNS: A 69-year-old man was admitted to our hospital with unexplained weight loss. Endoscopy revealed a submucosal mass without any ulcer on its surface located on the body of the stomach. The results of 2 gastroscopic mucosal biopsies were chronic inflammation. DIAGNOSES: The clinical diagnosis by computed tomography (CT) and gastroscopy was gastrointestinal stromal tumor (GIST) preoperatively. The postoperative pathological examination demonstrated this tumor as moderately differentiated SCC. INTERVENTIONS: Total gastrectomy, distal pancreatectomy, and splenectomy were performed. OUTCOMES: The patient was discharged 7 days after the surgery without any complications. The follow-up CT scan showed no evidence of metastatic disease 6 months after surgery. LESSONS: Large primary gastric SCC could present as a submucosal mass. Gastroscopic mucosal biopsy may not be able to get tumor tissue due to inflammatory reaction.