Sarcomatoid salivary duct carcinoma.

The so-called sarcomatoid salivary duct carcinoma (SSDC) is one of the variants of salivary duct carcinoma (SDC). This neoplasm is characterized by the presence of both a carcinomatous and a sarcomatoid tumor component. The histology and nomenclature of such neoplasms has been a matter of debate for many years. The histologic, immunohistochemical, and electron microscopic findings including those of 4 previously described cases of SSDC are defined and the different attitudes concerning their etiology will be discussed. In addition, the fine-needle aspiration biopsy of such a case is presented for the first time. In analogy to typical SDC there seems to be a predilection for elderly men and a location in major salivary glands. The resected SSDC tumors measured between 1.5 and 3.5 cm. Histologically, each case was a composite of SDC and sarcomatoid carcinoma. Immunohistochemical positivity for epithelial membrane antigen (EMA) and cytokeratins (AE1/AE3, CAM 5.2) was shown in the sarcomatoid tumor component. The important cytomorphologic feature of SSDC is the presence of cohesive clusters and flat sheets of cells with a cribriform pattern, in combination with an atypical spindle cell component. The use of the term SSDC seems more appropriate than the term carcinosarcoma , as the immunohistochemical, electron microscopic, and recent molecular findings in this and other biphasic neoplasms imply a monoclonal origin.