Extended Parotid Tumors with Origin in the Parotid Tissue

Abstract

Primary tumors of the parotid gland arise either in the superficial lobe, deep lobe, isthmus, accessory lobe, or Stensen’s duct, which will result in different behaviors concerning local spread and different clinical presentations. The various topographic and histologic possibilities, especially in the presence of extended tumors, will lead to a difficult differential diagnosis. Primary tumors must be differentiated from involvement of the parotid gland by direct invasion from tumors in neighboring areas and from metastatic disease to the parotid gland. Clinical suspicion is extremely important in order to properly address unusual individual cases and avoid the trap of approaching all parotid masses in the same manner that could eventually lead to either unnecessary or incomplete treatment. The suspicion is raised first by clinical examination and will be strengthened by further imaging studies, and eventually the final diagnosis will be confirmed by pathology. A great variety of histological types have been described in primary as well as secondary tumors to this area. Although statistical data suggests a great prevalence of certain malignant parotid tumors over others, the surgeon must not underestimate the possibility of rare tumors arising in this area that may require a different therapeutic approach. It is a challenge for the surgeon to manage certain complex tumors encountered in the parotid area. The aim of establishing the origin of the extended parotid gland tumor is to tailor the treatment according to the known behavior of tumors originating in the parotid tissue and to avoid the danger of under- or overtreatment.