Residual gastric cancer with a mixed small cell neuroendocrine and keratinizing squamous cell carcinoma: A case report.

Background: Despite advancements in early detection and treatment, the prognosis and histological types for residual gastric cancer (GC) remains poor.

Case summary: This case report presents a rare occurrence of residual GC featuring a combination of small cell neuroendocrine carcinoma (SCNEC) and squamous cell carcinoma (SCC) in a 60-year-old male patient. The patient, with a history of Billroth II gastrectomy for duodenal ulcer bleeding, presented with gastrointestinal bleeding. Preoperative computed tomography and positron emission tomography-computed tomography indicated adenocarcinoma with tumor and abdominal lymph node metastasis. The patient underwent laparoscopic total gastrectomy and lymph node dissection for residual GC. Histological examination of the resected tumor confirmed the presence of both SCNEC and SCC. Postoperatively, the patient underwent adjuvant chemotherapy four times. Two years later, the patient was found to occur esophageal cancer and was performed a small bowel stoma and radical esophagectomy.

Conclusion: In this case report, we detail a rare instance of residual GC with mixed SCNEC and SCC, emphasizing the complexity of diagnosis and treatment, and the need for ongoing research.