A Case of Sarcomatoid Carcinoma Arising from Mucinous Cystadenocarcinoma of Appendix

ABSTRACT

Sarcomatoid carcinoma or carcinosarcoma is a very rare biphasic tumor characterized by a combination of malignant epithelial and mesenchymal cells. The pathogenesis of sarcomatoid carcinoma is not fully elucidated and the guideline of treatment has not been established yet. Although the upper aerodigestive tract, lung and female urogenital system are known to be the most frequently affected, this tumor also can occur in various sites, including the digestive tract. Since sarcomatoid carcinoma in colon was firstly reported in 1986, 24 cases have been reported to date. We report a rare case with sarcomatoid carcinoma of appendix. Interesting histologic feature of our case was the presence of mucinous cystadenocarcinoma with morphological "transition" between carcinomatous and sarcomatous tissue. To our knowledge, this is the first case of sarcomatoid carcinoma arising from mucinous cystadenocarcinoma of the appendix.