Primary Squamous Cell Carcinoma of the Stomach: A Case Report With a Review of Japanese Literature

Abstract

Introduction: Primary squamous cell carcinoma (SCC) of the stomach is extremely rare and its pathogenesis still remains unclear. We present a case of primary SCC which seems to have originated from the ectopic squamous cell epithelium in the stomach. Case: A 66-year-old woman with a two-week history of exertional dyspnea was brought by ambulance. Her blood test revealed severe anemia (Hb=3.7g/dl) and gastrointestinal endoscopy was performed. The white-coated 60mm (long-side) Borrmann type 1 tumor was located at the lesser curvature in the cardiac lesion with no appearance of epithelium (Figure 1). The normal mucosa was slightly elevated and covered the tumor from the stomach to the upper end of the esophageal gastric junction. The biopsy specimens of the tumor demonstrated primary SCC and an abdominal operation was performed. On histopathological examination of the tissue samples obtained in the operation, the ectopic squamous cells were observed in the normal gastric mucosa of a part of the tumor and the primary SCC of the stomach had invaded the lower part of esophagus (Figures 2 and 3). In addition, stomach lesser curvature lymph node had metastasis of SCC. After the operation, she was treated with 5-fluorouracil and cisplatin, and no evidence of recurrence has been seen one year after treatment.Figure 1Figure 2Figure 3Results and Discussion: In Japan 45 cases were reported which had fulfilled the diagnostic criteria of primary SCC of the stomach by the Japanese Society of Gastroenterology from 1992 to 2014. 92.2% of all the SCC cases of advanced gastric cancer, 40% were Borrmann type 2, and 28.9% were type 1. However, the flat type is common in adenocarcinoma of the stomach, which is usually found in the early stages. Over half of the cases of SCC were in the upper gastric body and tended to infiltrate strongly into the submucosa also invading the lower esophagus as our case presented. Conclusion: We reported this case of primary SCC of the stomach which is rarely seen in Japan and collected data from the cases reported to the Japanese Medical Association.