Rare squamous cell carcinoma of the jejunum causing perforated peritonitis: A case report

BACKGROUND: Adenocarcinoma has the highest incidence among malignant tumors of the small intestine (SI). Squamous cell carcinoma (SCC) often occurs in organs covered with squamous epithelium. Primary or metastatic SCC originating from the SI is very rare, with very few cases reported in the literature. CASE SUMMARY: This case report involves a 69-year-old man who developed abdominal pain after lunch. After admission, an abdominal computed tomography scan revealed perforation of the alimentary canal and multiple abnormal low-density lesions in the liver. During laparotomy, an approximately 4 cm × 3 cm-sized solid tumor was found in the jejunum, located 30 cm from the Treitz ligament, with a perforation. An intestinal segment of approximately 15 cm was removed, including the perforated portion. The pathological result was SCC. In combination with liver imaging, a diagnosis of SI SCC with multiple liver metastases was considered. The patient died from hepatic failure 1 mo after the operation. CONCLUSION: SI tumors are very rare compared to those originating in other digestive organs. Due to its insidious onset, the diagnosis of this disease is usually delayed. Clinicians must pay close attention to digestive symptoms such as persistent abdominal pain and melena.