REVIEW ARTICLE Management of Malignant Submandibular Gland Tumors ALESSANDRA RINALDO 1 , ALFIO FERLITO 1 , PHILLIP K. PELLITTERI 2 , K. THOMAS ROBBINS 3 , ASHOK R. SHAHA 4 , PATRICK J. BRADLEY 5 , LUIZ P. KOWALSKI 6 and WILLIAM I. WEI 7 From the Departments of Otolaryngology  /Head and Neck Surgery, 1 University of Udine, Udine, Italy and 2 Geisinger Medical Center, Danville, Pennsylvania, USA, 3 Gainesville, Florida, USA, 4 Head and Neck Service, Memorial Sloan /Kettering Cancer Center, New York, New York, USA, 5 Department of Otorhinolaryngology */Head and Neck Surgery, Queens Medical Centre, Nottingham, UK, 6 Head and Neck Surgery and Otorhinolaryngology Department, Centro de Tratamento e Pesquisa, Hospital do Cancer AC Camargo, Sa ˜o Paulo, Brazil and 7 Division of Head and Neck Surgery, Otorhinolaryngology, Plastic and Reconstructive Surgery, Department of Surgery, University of Hong Kong Medical Center, Queen Mary Hospital, Hong Kong, People’s Republic of China INTRODUCTION Malignant submandibular gland tumors are quite diverse in terms of their histology and biological behavior. They account for :/8  /12% of all salivary neoplasms (1, 2), with the probability of a malignant diagnosis in :/50% (3  /5) of cases. It is important to remember that statistics concerning the distribution of salivary gland tumors and the proportion that are malignant are usually derived from the tumor regis- tries of large tertiary care centers, and are subject to obvious referral bias (6). An analysis of submandib- ular gland neoplasms excised over a 10-year period (1988  /97) in a fixed UK population in Nottingham revealed an incidence of 9% overall, with a distribu- tion of 66% benign and 34% malignant tumors (7). EMBRYOLOGY AND ANATOMY The submandibular or submaxillary gland develops as a solid proliferation from the epithelium of the stomodeum, and in particular from the endodermal germ layer, during weeks 6  /7 of gestation. In contrast to the parotid gland, which contains only serous glands, the submandibular gland contains both serous and mucous glands. Serous units predominate, ac- counting for :/90% of the acinar cells. The submandibular gland is the second largest salivary gland in the human body and is located in the submandibular triangle. This space is bound inferiorly by the anterior and posterior bellies of the digastric muscle and superiorly by the inferior border of the body of the mandible, with the floor being formed in part by the mylohyoid muscle. The sub- mandibular gland weighs :/7  /15 g and is anatomi- cally divided into superficial and deep lobes by the posterior edge of the mylohyoid muscle. The deep lobe cannot be palpated superficially in the neck but can be palpated in the floor of the mouth. The submandib- ular gland is covered by a fine fibrous capsule derived from the deep cervical fascia. The lingual and facial arteries supply the submandibular gland. Three im- portant nerves */the hypoglossal, the lingual and the marginal mandibular branch of the facial nerve */are intimately related to the submandibular gland. The facial nerve provides the sensory and secretory func- tions of the submandibular gland via the chorda tympani. The secretory innervation to the gland derives from parasympathetic fibers that travel with the lingual nerve (8). The lateral aspect of the gland lies deep to the platysma and the marginal branch of the facial nerve. The deep aspect of the anterior portion of the gland is adjacent to the mylohyoid muscle and its motor nerve, whereas the posterior portion of the gland extends posteriorly and medially to this muscle. Here it is closely related to the lingual and hypoglossal nerves and the floor of the mouth superiorly. Unlike the parotid gland, the submandib- ular gland does not contain any intraparenchymal lymph nodes, but three to six lymph nodes lie adjacent to the gland in the submandibular triangle. Lymphatic vessels originating in the gland drain either to the adjacent preglandular or prevascular nodes or to nodes in the upper jugular chain (1). The union of several ductal tributaries forms the submandibular salivary duct (Wharton’s duct), which is :/5 cm long. It emerges from the deep lobe of the submandibular gland, and runs medially, forwards and upwards beneath the mucous membrane of the floor of the mouth to end at the sublingual papilla, close to the midline to the side of the lingual frenulum. It has on its anterolateral aspect the sublingual salivary gland, some ducts of which drain directly into it. ETIOLOGY The etiology of submandibular neoplasms is poorly understood. Low-dose ionizing radiation has been implicated (1). In a study by Spitz et al. (9) of 64 patients with histologically confirmed salivary gland cancer, which involved the submandibular gland in 18 (28.1%), the authors did not find significant differ- ences between cases and control subjects with respect to tobacco exposure or specific occupational or leisure-time exposures. They reported that associations Acta Otolaryngol 2003; 123: 896  /904 # Taylor & Francis 2003. ISSN 0001-6498 DOI 10.1080/00016480310016406