[Carcinoma on pleomorphic adenoma in cervical salivary heteropia. Handling of one case and literature review].

The presence of salivary tissue outside of the salivary glands, a term called "salivary heterotopia," is not very common. The co-existence of carcinoma expleomorphic adenoma in a salivary heterotopia in the upper third of the neck can be considered unusual. We present an infrequent and clinically unsuspected case of carcinoma expleomorphic adenoma in the upper third of the neck and independent of the salivary glands. The tumour developed within heterotopic salivary tissue, with the histopathological study of the surgical extract being decisive for its diagnosis. The cervical salivary embryogenesis of heterotopias and their oncogenesis is analyzed. Their clinical signs are reviewed to indicate the difficulty in distinguishing the different types of diagnosis from other primary or metastatic tumours so as to assist in choosing the therapy to follow.