A case report and literature review of a rare primary multiple small intestinal sarcomatoid carcinoma with co-driver gene mutations

Abstract

Background Sarcomatoid carcinoma (SCA) is a relatively rare malignant tumor, and primary SCA occurring in the small intestine is even rarer, characterized by the co-existence of malignant epithelial cells and sarcomatoid differentiation (spindle/giant cell) components. Compared with other malignant tumors in the small intestine, it has greater invasiveness and earlier metastasis. Case presention We provide a complete case report on the clinical, imaging, genetic characterization, and treatment process of primary multiple small intestinal SCA. The patient underwent surgery, XELOX chemotherapy, and exploratory application of a multi-target tyrosine kinase inhibitor—anlotinib, however the condition progressed rapidly and he died within 3 months. This is the second report of systematic gene sequencing in the small intestine SCA, and co-mutations in key driving genes of KRAS, TP53, and PTPRT have been identified, with PTPRT being the first reported mutation in SCA. Conclusion Small intestine SCA has highly invasiveness and poor prognosis, while according to our statistical data primary multifocal small intestine SCA may have an even poor prognosis. This case was treated exploratorily with a multi-target tyrosine kinase inhibitor, anlotinib, but did not effectively control tumor growth and disease progression. This case provides reference guidance for the treatment of rare diseases such as sarcomatoid carcinoma in the future.