Salivary Gland Tumor Major salivary glands Parotid Submandibular Sublingual glands Minor salivary glands 500 700 in mucosa of upper aerodigestive tract Half are located on the hard palate
Parotid Gland The largest salivary gland Composed almost entirely of serous acinar cells Accounts for the majority of salivary flow in an active state but only provides 25 % of the total volume of saliva Facial nerve divides the gland into superficial lobes (80%) and deep lobes (20%).
Parotid Gland The most common site of salivary neoplasms Most tumors involve the superficial lobe. Successful surgery depends on identification, dissection, and preservation of the facial nerve and its branches (frontal, zygomatic, buccal, marginal mandibular, and cervical)
Submandibular Gland The second largest salivary gland Composed of both mucous and serous secretory cells Supplying approximately 70 per cent of the total volume of saliva Wharton's duct drains the gland, eventually opening a few millimeters lateral to the midline lingual frenulum in the anterior floor of the mouth
Sublingual Gland The smallest of the major salivary glands Produces predominantly mucous secretions Lies just beneath the mucosa of the anterior floor of the mouth
Salivary Gland Tumor Site Parotid gland % of all Neoplasms 67 % of Malignant 25 Submandibular gland 8 50 Minor salivary glands 27 81 Shah JP, el al. 1990
Diagnostic Workup History: rapid growth, pain Physical examination: - cranial nerve palsy - neck node enlargement - hard consistency and fixation - distant metastasis - submucosal swelling (minor salivary gland)
Diagnostic Workup Radiologic imaging: CT, MRI - lesions fixed to adjacent bony structures - lesion involves the parapharyngeal space - minor salivary cancers arising in the palate, nasal cavity, nasopharynx and paranasal sinuses
Diagnostic Workup FNA cytology - confirming the diagnosis of malignancy - distinguish between salivary and nonsalivary (lymph node) pathology - diagnosis of tuberculosis and lymphoma * A negative finding cannot rule out cancer
Benign Parotid Tumors Pleomorphic adenoma (mixed tumor): 80% Carcinoma ex pleomorphic adenoma 1 7% Warthin s tumor (papillary cystadenoma lymphomatosum): 10-15% Monomorphic adenoma: adenolymphoma, oxyphil adenoma, sebaceous adenoma, basal cell adenoma, clear cell adenoma Benign lymphoepithelial lesions: AIDS
Pleomorphic Adenoma A benign tumor composed of cells exhibiting the ability to differentiate to epithelial (ductal, and nonductal cells) and mesenchymal (chondroid, myxoid and osseous) cells
Pleomorphic Adenoma Most common neoplasm of salivary glands (45-74%) Average age 40-45 years Slow growing and asymptomatic A single nodular, firm, mobile, slightly compressible mass. Recurrent lesions occur as multiple nodules and are less mobile than the original tumor
Warthin s Tumor Occurs only in the parotid gland Second most common benign tumor of parotid gland Bilateral 10% and multiple lesions 10% More common in males (26:1) and smokers Occurs as a painless, fluctuant mass Retrograde infection Ear symptoms (tinnitus, deafness, earache)
Management of Benign Parotid Tumors Superficial parotidectomy with preservation of the facial nerve and its branches. Inadequate local excision or enucleation are prone to local recurrence and nerve injury. Any tumor in the parotid area is considered a parotid tumor until proved otherwise. For a very large deep-lobe parotid tumor, a lowerlip split incision and mandibulotomy approach may be required
TNM Staging for Cancers of the Major Salivary Glands Primary tumor (T) Classification TX Primary tumor cannot be assessed T0 No evidence of primary tumor T1 Tumor 2 cm in greatest dimension without extraparenchymal extension T2 Tumor 2 cm but 4 cm in greatest dimension without extraparenchymal extension T3 Tumor having extraparenchymal extension without seventh nerve involvement and/or 4 cm but 6 cm in greatest dimension T4 Tumor invades base of skull, seventh nerve, and/or 6 cm in greatest dimension
TNM Staging for Cancers of the Major Salivary Glands
TNM Staging for Cancers of the Major Salivary Glands Stage I T1 N0 M0 T2 N0 M0 Stage II T3 N0 M0 Stage III T1 N1 M0 T2 N1 M0 Stage IV T4 N0 M0 T3 N1 M0 T4 N1 M0 Any T N2 M0 Any T N3 M0 Any T Any N M1
Complications of Parotidectomy Facial nerve injury Hematoma Infection Flap necrosis Salivary fistula Frey's syndrome
Malignant Salivary Gland Tumors Mucoepidermoid carcinoma is the most common cancer of the parotid gland and all salivary glands. Adenoid cystic carcinoma is the most common malignant tumor arising in the submandibular gland. In minor salivary sites, adenoid cystic carcinoma and adenocarcinoma are most prevalent.
Mucoepidermoid Carcinoma Occurs in major and minor salivary glands History of ionizing radiation Women to men = 1.5:1 Occurs as a solitary nodule, pain and trismus Facial paralysis Numbness of teeth in tumors close to teeth Ulceration or hemorrhage from minor salivary gland tumors
Mucoepidermoid Carcinoma Low or high grade. A standard superficial parotidectomy is adequate treatment for low-grade mucoepidermoid carcinomas. High-grade tumors can invade the facial nerve, and the incidence of lymph node metastasis at presentation is approximately 50%.
Malignant Mixed Tumor Two types: - carcinoma ex pleomorphic adenoma a long-term history of a benign mixed tumor with rapid growth and fixation to deeper structures and skin. - true malignant mixed tumor or carcinosarcoma 15 20% present with regional lymph node metastases.
Adenoid Cystic Carcinoma More common in parotid gland Most common malignant tumor of intraoral salivary glands Female to male ratio, 3:2 Local extension beyond the gross lesion Perineural involvement High incidence of local recurrence Distant metastases are common, mostly to the lung.
Factors Affecting Choice of Treatment The extent of the lesion at diagnosis (the clinical stage) - small lesions: surgical resection - large tumors invading adjacent structures: extensive resection with adjuvant radiotherapy - unresectable disease - disseminated disease
Factors Affecting Choice of Treatment Location - Borderline resectable lesions in inaccessible locations, such as tumors involving the base of skull, may be better suited for nonsurgical therapy such as chemoradiotherapy or neutron beam irradiation. Histology - Adenoid cystic carcinoma - High grade
Surgical Treatment for Malignant Parotid Tumors Minimal operation for parotid lesion is a superficial parotidectomy with preservation of facial nerve. Deep-lobe parotid tumor can be removed without injuring the facial nerve. A mandibulotomy approach may be necessary for better exposure of the parapharyngeal area.
Surgical Treatment for Malignant Parotid Tumors If the facial nerve is not paralyzed preoperatively and no direct extension into the nerve - preserve the nerve. If the nerve is sacrificed - immediate nerve grafting with interposition grafts - implantation of a Gold Weight in the upper eyelid to improve eye function and eye closure.
Surgical Treatment of Malignant Submandibular Gland Tumors Three important nerves in its vicinity: - ramus mandibularis - hypoglossal - lingual Block dissection - to remove entire contents of the submandibular triangle. - marginal or segmental mandibulectomy if required. - supraomohyoid neck dissection if indicated.
Surgical Treatment of Malignant Minor Salivary Gland Tumors depending on the site of origin - Lesions in the larynx: conservation laryngeal surgery or total laryngectomy - Tongue base: paramedian mandibulotomy - Palate: partial or subtotal maxillectomy. - Nasal cavity or paranasal sinuses: combined craniofacial resection or orbital exenteration in extensive disease
Cervical Lymph Nodes in Malignant Salivary Tumors Elective supraomohyoid neck dissection in - High-grade mucoepidermoid and primary squamous cell carcinoma. - High-stage lesions. Modified or radical neck dissection if - suspicious lymph nodes are found at surgery. - grossly palpable nodes at initial evaluation.
Indications for Radiotherapy Advanced inoperable cancer High-grade, high-stage primary tumor Positive margins after surgery Deep-lobe malignant tumors Lymph node metastases Tumor spillage at surgery
Prognosis Prognostic factor - tumor stage - grade - histologic type: acinic or low-grade mucoepidermoid tumors have a better prognosis. Generally, tumors of the submandibular gland and minor salivary gland are more aggressive than are parotid tumors
Cure Rates in Patients with Malignant Tumors