Multifocal small intestinal sarcomatoid carcinoma presenting as recurrent intussusception: a case report and literature review

Sarcomatoid carcinoma of the small intestine is a rare and aggressive cancer with both epithelial and mesenchymal features. Its nonspecific symptoms often lead to diagnosis only after surgical and pathological analysis. A 60-year-old man underwent emergency partial small intestine resection surgery for intestinal intussusception and obstruction. During surgery, a lesion near the ligament of Treitz was found but not removed due to bowel edema and safety concerns. Initial pathology showed sarcomatoid carcinoma. On the 7th postoperative day, the patient experienced nausea and vomiting, and a CT scan revealed recurrent jejunal intussusception. Positron emission tomography/computed tomography (PET/CT) showed high metabolic activity in the proximal jejunum without metastasis. He then had a radical segmental jejunal resection with jejunojejunostomy, and final pathology confirmed sarcomatoid carcinoma. He demonstrated significant recovery and was subsequently discharged in a stable condition. This case shows that small intestinal sarcomatoid carcinoma can be multifocal and lead to recurrent adult intussusception. Thorough intraoperative evaluation of the entire small bowel is crucial if malignancy is suspected. If immediate resection is unsafe during an emergency, a staged radical resection following decompression and optimization might be a viable surgical approach.