epithelial-myoepithelial carcinoma epithelial-myoepithelial carcinoma epithelial-myoepithelial carcinoma (emca) is a rare malignant tumour that typically arises in a salivary gland and consists of both an epithelial and myoepithelial component. they are predominantly found in the parotid gland and represent approximately 1% of salivary gland tumours. epithelial-myoepithelial carcinomamicrograph of an epithelial-myoepithelial carcinoma (right of image). the epithelial component has a tubular morphology and is evident only focally (upper left of image). benign serous glands (parotid salivary gland) are also seen (left of image). h&e stain.specialtyent surgery cause diagnosis emcas are diagnosed by examination of tissue, e.g. a biopsy. this tumour is characterised by biphasic tubular structures composed of inner ductal and outer clear myoepithelial cells. its appearance is very similar to adenomyoepithelioma of the breast, which may be the same tumour at a different anatomical site. the histologic differential diagnosis includes adenoid cystic carcinoma and pleomorphic adenoma. intermed. mag. high mag. prognosis they generally have a good prognosis. in one larger study, the 5-year and 10-year survival were over 90% and 80% respectively.