What is a Carcinosarcoma?

A carcinosarcoma is a tumor involving the epithelial cells that line the body's organs and the connective tissues, like cartilage or bone. This combination of carcinoma and sarcoma is quite rare but aggressive, suggesting a poor prognosis in many cases. A small percentage of breast cancers meet the diagnostic criteria for carcinosarcoma, and it has occasionally been found as a cause of malignant lung tumors. Its most prevalent location is in the uterus and nearby reproductive tissues, where it accounts for up to five percent of reported neoplasms.

Both the epithelial and connective tissue must be cancerous for a diagnosis of carcinosarcoma, which is a mixed cell line neoplasm. Carcinomas are cancers of the epithelical cells that line skin and many organs in the body, and are quite common. Sarcomas are rare, malignant tumors of connective tissues including bone and cartilage, and occur less frequently among reported cases of cancer each year. In carcinosarcoma, both types of neoplasm are present in the same organ or tissue. The older name for this disease, malignant mixed mesodermal tumor, reflects the fact that connective tissue originates from the embryonic mesoderm.

In the breast, carcinosarcomas are the rarest type of cancers. While carcinomas commonly cause mammary neoplasm, sarcomas occur in less than one percent of cases. Soft tissue sarcomas in breast fat are similar to mixed cell line cancers, but are not the same in their origin or aggressiveness.

There is a significant risk that the tumor will spread from the breast into adjacent pulmonary tissue. Treatment by surgical removal of the malignant tissue has had mixed results. It is important to note that the number of cases available for statistical analysis of prognosis and treatment success has been small.

Pulmonary carcinosarcoma, while uncommon, is an aggressive malignancy that was historically difficult to diagnose distinctly from other lung cancers. Microscopic slide stains were once used to identify the presence of both connective and epithelial cancer, but immunohistology, an improved diagnostic technique introduced in the 1980s, is more effective. The survival and recovery prognosis depends less on the carcinoma component of the cancer than on the connective tissue tumor — the sarcoma, which is often the variable that affects survival and recovery.

Some female reproductive organs contain both epithelial and connective tissue, which makes them relatively more vulnerable to carcinosarcoma. In the uterus, fallopian tubes, and ovaries, the condition is also called a mixed Müllerian tumor. Sometimes the sarcoma is present in the endometrium, but on other occasions it is found in muscle or cartilage outside the uterus or ovaries. Generally occurring in post-menopausal women, its causes are unclear. There are, however a few known risk factors that are shared with other cancers, including estrogen therapy and radiation treatment near the female reproductive organs.