Sarcomatoid Carcinoma of the lung: A rare case of three small intestinal intussusceptions and literature review

INTRODUCTION: Sarcomatoid carcinoma is an extremely rare, biphasic tumor characterized by a combination of malignant epithelial and mesenchymal cells. Limited data showed that most cases occurred with advanced local disease and metastasis. PRESENTATION OF CASE: We present a rare case of a 60-year-old man with three small intestinal intussusceptions due to metastatic pulmonary carcinosarcoma. He was explored for chest pain and hemoptysis in Emergency room. Due to his chest symptoms he had a computed tomography (CT) scan of the chest which showed a lesion about 60 mm in diameter in the inferior lobe of the left lung. After 2 weeks physical examination demonstrated a distended abdomen and auscultation was indicated by hyperactive bowel sounds. Further imaging studies with abdominal computed tomography (CT) scan, showed multiple protruding small bowel tumors with entero enteric intussusceptions at three sites requiring a massive bowel resection at surgery. The pathology showed that it was positive for cytokeratin, vimentin, CD-34, and LIS; CK7 was focally positive; and CD117, CD20, and desmine were negative. The final diagnosis was metastatic small bowel carcinosarcoma with a lung primary. DISCUSSION: Lung carcinosarcoma is a high grade biphase neoplasm. The survival rate at 6 months is only around 27%. CONCLUSION: There are rare reports of small intestinal intussusceptions caused by metastatic lung carcinosarcoma, this presentation shows the third case in literature. Physicians should be more alert to symptoms or signs indicating GI metastais in patients with a history of lung cancer.