Carcinosarcoma ex pleomorphic adenoma of the salivary gland is an extremely rare tumor of the
major and minor salivary glands that is composed of a mixture of both carcinomatous and sarcomatous
elements with an identifiable benign epithelial and mesenchymal tumor counterpart.

This report describes a rare case of carcinosarcoma ex pleomorphic adenoma involving the left parotid
gland in a 61-year-old female with no history of a long-standing pleomorphic adenoma, nor a recurrent
pleomorphic adenoma, and describes its morphology and important immunohistochemistry findings.
Carcinosarcoma ex pleomorphic adenoma contains features of the two tumors under malignant mixed
tumors, which are carcinosarcoma and carcinoma ex pleomorphic adenoma. Immunohistochemistry
studies were done to document the epithelial and mesenchymal areas from both the malignant and
benign sections of the tumor and to classify the carcinoma and sarcoma component, consisting of
adenocarcinoma, not otherwise specified for the carcinoma component, and myxoid chondrosarcoma
and mesenchymal chondrosarcoma for the sarcoma component.

The paucity of documented cases of carcinosarcoma ex pleomorphic adenoma in prior scientific
publications requires reporting cases such as this. Furthermore, the report provides an insight into
the more complex molecular and structural changes that manifest as cancer behavior in the tumors
of the salivary gland. The case contributes to the fund of knowledge for diagnosis and improvement
of quality of care.

Human ; Adenoma ; Carcinoma ; Carcinosarcoma