244  Tumours of the salivary glands

 Definition

Carcinosarcoma is a malignant tumour composed of a mixture of both carcinomatous and sarcomatous elements.

ICD-O code 8980/3

Synonym

True malignant mixed tumour

Epidemiology

Carcinosarcoma is extremely rare; approximately 50-60 cases have been reported to date {47,898,911,932,1010, 1320,2377,2466}. The mean age at presentation was 58 years with a range of 14- 87 years {899}. A number of patients have had a history of recurrent pleomorphic adenoma {2466} and several cases have arisen in a pleomorphic adenoma (carcinosarcoma ex pleomorphic adenoma) {899,1010,1320,1400}.

 Localization

 Two-thirds have arisen in the parotid gland, approximately 19% in the submandibular glands, and 14% in the palate {899}. One case has been reported in the tongue and one in the supraglottic region {691}.

Clinical features

Patients typically present with a mass, which may be painful.

 Macroscopy

Tumours are well to poorly circumscribed.

Histopathology

The tumour is composed of mixtures of carcinomatous and sarcomatous elements in varying proportions {225}. Chondrosarcoma and osteosarcoma are the most common sarcomatous elements and moderate to poorly differentiated ductal carcinoma or undifferentiated carcinoma are the most common carcinomatous components. Local tissue infiltration and destruction are characteristic of this neoplasm.

Genetics

LOH at 17p13.1, 17q21.3 and 18q21.3 has been found in one carcinosarcoma. Sequencing studies excluded TP53 mutations, suggesting inactivation of another tumour suppressor gene at 17p13 {932}.

Prognosis and predictive factors

Treatment is wide surgical excision combined with radiotherapy. Almost 60% of patients die of local recurrence and/or metastatic disease (lungs, bones, central nervous system), usually within a thirty month period {47,899,2466}