------------------------------------------------------------------------------- TITLE: PAROTID TUMORS SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds DATE: APRIL 28, 1993 RESIDENT PHYSICIAN: John B. Kinsella MB, FRCS FACULTY: Francis B. Quinn, Jr., M.D. DATABASE ADMINISTRATOR: Melinda McCracken, M.S. ------------------------------------------------------------------------------- "This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purpose of stimulating group discussion in a conference setting. No warranties, either express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." INTRODUCTION: The term 'parotid' is derived from the greek language and literally means 'near the ear'. Tumors in any of the salivary glands are uncommon. Their incidence in the USA is estimated at 40 cases per million, with 80 to 85 per cent of these occurring in the parotid. Parotid neoplasia are slightly more common in females. There is a slight racial predilection for African- Americans over Caucasians. The majority of patients present in the age range 30 to 70 years. The early ambiguity in histologic classification and biologic characteristics of these tumors meant that therapy was poorly directed prior to the 1950s. McFarland in 1953 proposed that surgical treatment for these neoplasms was unnecessary. Improvement in our knowledge of the pathology and clinical behavior of these tumors along with more sophisticated surgical methods during the last three decades has led to more appropriate and effective treatment. SURGICAL ANATOMY: The gland is divided into a superficial(90%) and a deep(10%) lobe by the presence of the facial nerve. It is incompletely invested by a continuation of the deep cervical fascia, which surrounds the SCM posteriorly and overlies the masseter muscle anteriorly. Three important structures run through the substance of the gland, namely the facial nerve(superficial), the posterior facial vein(middle) and the external carotid artery. Its boundaries are as follows: anterior: masseter, ramus of mandible, medial pterygoid posterior: EAC, mastoid process, base of styloid process superior: zygomatic arch inferior: SCM, posterior belly of digastric medial: parapharyngeal space lateral: parotid fascia, subcutaneous tissue, skin INTRA-OPERATIVE LOCATION OF MAIN TRUNK OF FACIAL NERVE: * 1cm deep and inferior to the tragal pointer * nerve bisects thetympanomastoid suture * nerve bisects angle between posterior belly of digastric and tympanic plate * buccal branch of facial nerve runs parallel to and 1cm below the arch of the zygoma - trace this branch back to main trunk * identify the nerve in the mastoid and follow it distally to the extratemporal portion * styloid process - medial and anterior INTRA-PAROTID BRANCHES OF FACIAL NERVE: The main trunk of the facial nerve exits skull at the stylomastoid foramen and gives off branches to the posterior auricular, stylohyoid and posterior belly of digastric muscles. It then enters the parotid and almost immediately divides into two divisions: * upper temporal facial * lower cervical facial These two division give rise to five main branches to muscles of facial expression: * cervical-innervates platysma * marginal mandibular-innervates lower orbicularis oris, depressor anguli oris, depressor labii inferioris, and mentalis * buccal-innervates zygomaticus major and minor, levator anguli oris, buccinator, and upper orbicularis oris. This branch has the richest collateral network and is most significant in terms of emotional and mimetic facial function * zygomatic-innervates lower orbicularis oculi * temporal-innervates the frontalis, corrugator supercilii, procerus, and upper orbicularis oculi. Recovery of function after paralysis of this branch is poorest due to almost complete lack of anastomoses with other branches ANATOMY OF STENSEN'S DUCT: It penetrates the buccinator muscle and opens in the mouth opposite the second upper molar. It may be located along a line drawn from the external auditory meatus to the columella. EMBRYOLOGY AND ETIOLOGY: The salivary glands originate from the aerodigestive tract as small buds off the oral cavity. This process begins at about 4 to 6 weeks gestation. The parotid develops first but encapsulates last allowing lymph nodes to become entrapped within the substance of the gland. There are two theories on the histogenesis of salivary gland neoplasms. One speculates that differentiated cells undergo a process of dedifferentiation into the multiple cell types. The other theory utilizes the progenitor cell present in the intercalated duct and excretory duct to explain differentiation into the various histologically varied neoplasms. Little is known about the etiology of these tumors. The inoculation of newborn mice with polyoma virus is reported to provoke the formation of salivary neoplasms, although there is no evidence to incriminate a viral agent in humans. Similarly, hydrocarbons have been used to induce salivary neoplasms in laboratory animals. The evidence that low dose radiation may induce these tumors in humans is much more convincing and is derived mainly from studies of people exposed to the effects of the atomic bomb at Hiroshima. Therapeutic radiotherapy has also been shown to increase the risk for development of these neoplasms. An epidemiological case control study carried out in the Los Angeles area by Preston-Martin and White and published in 1990 attributes 15 per cent of parotid cancers to prior diagnostic radiation exposure, 85 per cent of the total exposure coming from dental examinations. The authors point out that the dosage of diagnostic dental radiography has decreased substantially in recent years. However, it is not known if the current low doses are significantly carcinogenic. DIAGNOSIS: Any swelling near the ear is best considered a parotid tumor until proved otherwise, but opinions differ as to what constitutes adequate evaluation. The following diagnostic aids may be useful: * CT/MRI: unlikely to influence management of well-defined, freely-movable tumors. Valuable in the evaluation of patients presenting with palate or tonsil swellings in order to distinguish between deep lobe parotid tumors, parapharyngeal lesions, or minor salivary gland neoplasms. Whether MRI scanning will replace CT is presently uncertain, but current reports suggest that a good quality T2 weighted image can delineate the position of the facial nerve with respect to tumor. * Radiosialography: this is based on the concentrating ability of the salivary gland striated ductal epithelium. These cells can extract Tc99m(pertechnetate) from the capillary network of the salivary glands. Gamma emissions from the radioactive material secreted from the ducts can then be identified during scanning of the gland. The presence of a hot mass is usually indicative of Warthin's tumor or oncocytoma. However, hot masses may occasionally be malignant. May occasionally be useful in counseling the elderly and high risk surgical patient who presents with a salivary gland mass. * FNA: simple to do and has a high degree of accuracy in the hands of an experienced cytopathologist. Diagnostic accuracy should be around 85 to 90 percent. (FNA = fine needle aspiration biopsy) * Frozen section: accuracy depends greatly on the experience of the pathologist in dealing with salivary neoplasms. One should not make critical surgical decisions based upon frozen section. CLASSIFICATION: The salivary glands are said to give rise to more types of histologically varied tumors than any other system of the body. Thus, pathologists and clinicians have had great difficulty in classifying these neoplasms and no single system has been universally accepted. A relatively simple classification was originally proposed by Foote and Frazell and modified by Spiro: BENIGN: * Pleomorphic adenoma * Monomorphic adenoma * Warthin's tumor * Benign cyst * Lymphoepithelial lesion * Oncocytoma MALIGNANT: * Mucoepidermoid * Malignant mixed * Acinic cell * Adenocarcinoma * Adenoidcystic * Epidermoid * Other An alternative classification has been proposed by Batsakis which adds information about the histogenesis of these tumors, but is certainly more complicated: BENIGN: * Mixed tumor (pleomorphic adenoma) * Papillary cystadenoma lymphomatosum (Warthin's tumor) * Oncocytoma * Monomorphic tumors -Basal cell adenoma -Glycogen rich adenoma -Clear cell adenoma -Membranous adenoma -Myoepithelioma * Sebaceous tumors -Adenoma -Lymphadenoma * Capillary ductal adenoma * Benign lymphoepithelial lesion * Unclassified MALIGNANT: * Carcinoma ex pleomorphic adenoma * Malignant mixed tumor * Mucoepidermoid carcinoma -Low grade -Intermediate grade -High grade * Adenoid cystic carcinoma * Acinous cell carcinoma * Adenocarcinoma -Mucus-producing adenopapillary and nonpapillary -Salivary duct carcinoma -Other adenocarcinomas * Oncocytic carcinoma * Clear cell carcinoma (nonmucinous and glycogen containing or nonglycogen containing) * Primary squamous cell carcinoma * Adenoid cystic carcinoma * Undifferentiated * Epithelial-myoepithelial carcinoma intercalated ducts * Miscellaneous * Metastatic * Unclassified AJCC CLINICAL STAGING:1988 REVISION: Primary tumor: T0 No evidence of primary tumor T1 Tumor 2cm or less in greatest diameter T2 Tumor more than 2cm but not more than 4cm in greatest diameter T3 Tumor more than 4cm but not more than 6cm in greatest diameter T4 Tumor more than 6cm in greatest diameter Note: All categories are subdivided: (a) no local extension; (b) local extension, defined as clinical evidence of skin, soft tissue, bone, or nerve invasion Lymph nodes: N0 No regional lymph node metastasis N1 Metastasis in a single ipsilateral lymph node, 3cm or less in greatest diameter N2a Metastasis in a single ipsilateral lymph node more than 3cm but not more than 6cm in greatest diameter N2b Metastasis in multiple ipsilateral lymph nodes, none more than 6cm in greatest diameter N2c Metastasis in bilateral or contralateral lymph nodes, none more than 6cm in greatest diameter N3 Metastasis in a lymph node more than 6cm in greatest diameter Distant metastasis: M0 No distant metastasis M1 Distant metastasis BENIGN TUMORS: PLEOMORPHIC ADENOMA: This accounts for 60% of all salivary neoplasms, and is most commonly found in the tail of the parotid. Grossly, mixed tumors are often irregular, lobulated and bosselated. The cut surface is gray or blue. It is essentially an epithelial tumor of complex morphology, possessing epithelial and myoepithelial elements arranged in a variety of patterns and embedded in a mucopolysaccharide stroma. Its capsule is the result of fibrosis of the surrounding salivary parenchyma which is compressed by the tumor, and is referred to as a false capsule. Since the capsule is formed in response to expansion by the neoplasm, it is frequently incomplete, and tumor may be seen projecting through the dehiscences as small bosselations which contact surrounding gland tissue. This lack of a complete capsule is a compelling reason for removing these tumors with as wide a margin as possible. The operation of enucleation, which has now been largely abandoned in favor of superficial parotidectomy, resulted in an unacceptably high rate of recurrence, often as high as 40% over a 30 year period. A recurrent mixed tumor is to be feared, since it represents not a discrete mass but a multiplicity of nodules. These may occur in the previous scar, subcutaneous tissue,both superficial and deep parotid parenchyma, the sheath of the facial nerve and the perichondrium of the external meatus. Further attempts at surgery may be fruitless given the widespread nature of the condition, and may cause damage to the facial nerve. 2 to 5 per cent eventual malignancy rate. WARTHIN'S TUMOR: This accounts for approximately 5% of all salivary tumors making it the second most common benign neoplasm. It usually occurs in the tail of parotid. It usually affects elderly males with a male to female ratio of 5 to 1. Grossly, Warthin's is well circumscribed, soft and cystic. The fresh specimen often contains a viscous chocolate-like fluid. Microscopically, the tumor is composed of papillary elements lining cystic spaces in a lymphoid stroma. The presence of lymphoid tissue within the tumor makes it susceptible to inflammation, often secondary to upper respiratory infection. The clinical features therefore include fluctuation in size and intermittent pain. Treatment is by superficial parotidectomy with recurrences a rarity. ONCOCYTOMA: This accounts for less than 1% of all salivary tumors and occurs almost exclusively in people who are greater than 50 years old. It is well circumscribed and usually has a solid, yellow-tan cut surface. Microscopically, it is composed of large polyhedral cells of varying sizes and shapes. The hallmark of oncocytomas is the presence of true oncocytes that contain large numbers of mitochondria. The diagnosis of oncocytoma should be made only when the entire lesion contains oncocytes. They rarely become malignant. Treatment usually consists of superficial parotidectomy. MONOMORPHIC ADENOMAS: Account for 1-3% of salivary neoplasms. It is commonest in elderly females but has a very broad age range. There are five histological sub-types according to Batsakis' classification system (basal cell, glycogen-rich, clear cell, membranous, myoepithelioma). Microscopically, the epithelium forms a regular pattern, usually glandular, and in which there is no evidence of the mesenchyme-like tissue so characteristic of mixed tumor. Treatment usually consists of superficial parotidectomy. SEBACEOUS TUMORS: Although sebaceous cells are commonly present within normal salivary gland tissue, sebaceous cell neoplasms are rarely seen within these glands. Two distinct histological sub-types occur: sebaceous adenoma and sebaceous lymphadenoma. Treatment usually consists of a superficial parotidectomy. HEMANGIOMAS: Represent more than 50% of childhood salivary neoplasms. More than half are present at birth and the great majority present within the first year of life. A cutaneous hemangioma is found in more than 50% of patients. Microscopically, the normal parotid tissue is replaced by vasoactive elements. Treatment usually consists of serial observation as the majority involute by the time the child reaches five years. PAROTID CYSTS: Prior to the HIV era, cystic lesions of the parotid were thought to occur rarely. Over the past decade, however, a substantial increase in the incidence of these lesions has been reflected by a corresponding increase in the number of cases reported in the literature. The issue that concerns head and neck surgeons is that the classic management for any parotid mass in general includes a superficial parotidectomy for treatment as well as biopsy. However, because elective surgery on HIV patients poses risks for both patients and health workers, and surgical management does not affect the underlying disease, we are now leaning toward a non-surgical management of parotid cysts in these patients. Huang et al recommend CT scanning (to confirm cystic nature) and fine needle aspiration cytology of all parotid tumors in patients at high risk for HIV infection. If the lesion is cystic on CT and benign on FNA, then they recommend watchful waiting and a non- surgical approach. Repeat needle aspiration for palliation is recommended. Although patients may request surgery for cosmetic or other unpleasant symptoms, Huang et al do not recommend the procedure. Surgery should be reserved for suspicious solid lesions, especially with cytology findings, such as abnormal cells or a uniform lymphoid population where further pathological diagnosis is warranted. Huang et al also feel that an elevated amylase level in the parotid FNA specimen is suggestive of benign cystic disease. Finally, they suggest that any patient who presents with a parotid cyst should be investigated for possible HIV infection. MALIGNANT TUMORS: MUCOEPIDERMOID CARCINOMA: This is the most common malignant tumor of the parotid gland. In the submandibular and minor salivary glands, adenoid cystic predominates. The parotid is the primary site for 89% of all the mucoepidermoid carcinomas of the salivary glands. The prevalence of this cancer is highest in the fifth decade, though it is also the commonest malignant salivary tumor in children. The male to female ratio is approximately 1 to 3. These tumors probably originate in the epithelial cells of the interlobar or intralobular salivary ducts. They contain mucin-producing and epithelial cells of the epidermoid type but do not possess myoepithelial cells. The biologic behavior of these tumors has been the subject of controversy. In particular it has been questioned whether there is a benign variety. These neoplasms can range from highly to very poorly differentiated. Today, most authorities recognize that even the most highly differentiated tumors can sometimes metastasize and that they are all malignant. However, the degree of differentiation is very important clinically and correlates well with the extent of local invasion, with the incidence of lymph node metastasis, and with the overall survival. Grossly, low grade tumors resemble benign pleomorphic adenomas. They are usually well circumscribed and the cut surfaces may show dilated cystic structures containing mucous material. High grade tumors are poorly circumscribed, infiltrating, and do not have a cystic appearance. Metastases from these tumors contain both mucin-producing and epithelial cells. The treatment for these cancers depends on the grade. Low grade tumors are usually adequately treated by superficial parotidectomy, whereas high grade malignancies require wide local excision and post-operative XRT. Recurrence may occur many years after treatment, so that one is never really safely considered 'cured'. The 15-year survival rate varies according to the grade of the tumor. Spiro et al quote a 15-year survival rate of 48% for low-grade and 25% for high- grade. ADENOID CYSTIC CARCINOMA: This is the second commonest malignant parotid tumor, and the commonest malignancy of the minor salivary glands. They account for 14% of cancers of the parotid gland. The majority of patients are between the ages of 40 and 60 years. These tumors are not encapsulated but appear circumscribed. There are three common histological patterns-tubular, cribriform, and solid. Neoplasms containing many tubular structures carry the most favorable prognosis, and those consisting mainly of solid nests of cells have the poorest. The cribriform pattern is the commonest. Here the majority of the cells are small and darkly stained and have scanty cytoplasm. The cells are arranged in nests that are fenestrated by round or oval spaces, thus creating the cribriform pattern. This cancer tends to grow slowly and spread relentlessly into surrounding tissues. Hematogenous metastases to lung and bone occur late in the course of the disease, in up to 50% of cases. Lymph node metastasis is unusual. They have a strong tendency for perineural invasion and may extend for long distances by this route. Treatment consists of wide local excision and post-operative XRT. If the facial nerve is involved, it may have to be resected right up to the skull base to obtain free margins. An extremely long period of observation is required if the prognosis is to be judged with any degree of accuracy. Spiro et al quote 5, 10, 15, and 20 year survival rates of 31, 18, 10, and 7 per cent, respectively. ACINIC CELL CARCINOMA: These tumors occur almost exclusively in the parotid gland where they account for 12 to 17 per cent of all cancers. They usually occur between the ages of 30 and 60 years with a male to female ratio of 1 to 2. They rank second only to Warthin's tumor in bilaterality, which occurs in 3% of cases. Grossly, they appear well circumscribed by a large layer of dense fibrous tissue. They are much the same color and consistency as normal salivary gland. As a group, acinic cell carcinomas behave as low-grade malignant tumors in that they have a strong tenancy to recur locally but seldom metastasize. Treatment consists of wide local excision. XRT is not felt to be effective This neoplasm must be followed for long periods after treatment. Spiro et al quote 5, 10, and 15 year survival rates of 76, 63, and 55 per cent respectively. ADENOCARCINOMA: This is a very heterogenous group of neoplasms, which, although capable of being separated onto separate histologic categories, are nonetheless of such low incidence when separated by categories that a detailed statistical analysis is extremely difficult. Altogether they account for perhaps 4% of all salivary tumors. Sub-types include mucinous adenocarcinoma, salivary duct carcinoma, and intercalated duct carcinoma. Mucinous adenocarcinomas can be further sub-categorized into invasive and non-invasive tumors, with associated 20-year survival rates of 20 and 40 per cent respectively. Salivary duct carcinomas occur predominantly in the parotid gland of elderly people, with a male to female ratio of 3 to 1. The majority are rapidly progressive, metastasizing early to regional lymph nodes and lungs. Intercalated duct carcinomas occur mainly in the parotid glands of elderly women. They behave like low-grade carcinomas with a 10-year survival rate of greater than 90%, and a recurrence rare of 60%. MALIGNANT MIXED TUMORS: Approximately 75% of these arise in the parotid gland. They account for between 3 and 12 per cent of all salivary malignancies. There are four histologic sub-types: * Carcinoma ex-pleomorphic adenoma is by far the commonest form. The malignant component is usually a poorly differentiated adenocarcinoma, and the metastases contain only adenocarcinoma. * True or primary malignant mixed tumor(carcinosarcoma)-here the malignant components are carcinoma and sarcoma and the metastases contain both elements. * Metastasizing mixed tumor. This is the most rare variant. Both the original tumor and its metastases consist of structures typical of benign mixed tumor. * In situ, or non-invasive carcinoma. This applies to those tumors without evidence of invasion of the capsule or the surrounding tissue. Invasive carcinomas in mixed tumors and true or primary malignant mixed tumors are highly aggressive. Treatment consists of wide local excision and neck dissection if nodes are present. Post- operative XRT is also recommended. The recurrence rate over a 5-year period is between 40 and 70 per cent and the rate of metastasis to regional nodes is 25 per cent and to distant organs, 33 per cent. Spiro et al quote 5, 10, and 15 year survival rates of 40, 24, and 17 per cent, respectively. SQUAMOUS CELL CARCINOMAS: These account for approximately 0.5% of all parotid tumors. They are commoner in the submandibular glands probably because of the much higher incidence of obstructive duct disease there. This neoplasm tends to affect people of 60 years and over. The microscopic appearance is identical to that of squamous carcinoma in other tissues. Before ascribing squamous carcinoma to a major salivary gland as the primary site, one must exclude mucoepidermoid carcinoma and metastasis or extension to the gland from an extrasalivary glandular source. Treatment consists of wide local excision and neck dissection, if adenopathy is present. Post-operative XRT is also recommended. 5-year survival is approximately 45%. NONEPITHELIAL TUMORS: These account for less than 5 per cent of all salivary gland neoplasms. They include lipomas, neurofibromas, sarcomas, and lymphomas. Primary malignant lymphomas of the salivary glands are rare and the parotid is the usual site. Most patients are in the sixth or seventh decade of life. To qualify as a primary salivary lymphoma the following criteria must be fulfilled: * Enlargement of a salivary gland must be the first clinical manifestation of disease * Histologic proof that the lymphoma involves salivary gland parenchyma * Architectural and cytologic confirmation of the malignant nature of the lymphoid infiltrate. All sub-types of lymphoma may occur in the salivary glands, but Hodgkin's is extremely unusual. METASTASIS TO THE PAROTID: This may occur by lymphatic spread, hematogenous dissemination, or contiguous extension. Yarington, in a series of 250 parotidectomies performed for clinically primary parotid tumors, found 4% metastatic neoplasms from an unsuspected primary source. Since the lymphatic drainage of the scalp, face, external ear, eyelids, and nose is to both intraglandular and periglandular lymph nodes, it is not surprising that cutaneous squamous cell carcinoma and melanoma arising in these areas are the metastatic malignant tumors most often found in the parotid lymph nodes. Blood-borne metastatic carcinomas from infraclavicular organs arise most commonly from a lung primary and, less often, from one in the breast, kidney or gastrointestinal tract. Malignant secondary neoplasms of the parotid carry a grave prognosis with a 5-year survival as low as 12.5%. PAROTID TUMORS IN CHILDHOOD: These are very unusual in children with only 3% of all parotid neoplasms occuring in the first 16 years of life. Mixed tumors are by far the commonest benign epithelial neoplasm in children. The peak incidence occurs at 10 years of age.Behavior and treatment does not differ from similar tumors in adults Hemangiomas are the next commonest, accounting for nearly 10% of all childhood parotid swellings. They are usually present at birth and are located at the angle of the mandible. They are commonest in Caucasian females. They are often diffuse and appear to increase in size with crying or straining. A concomitant hemangioma or telangiectasia in the overlying skin is fairly common. There is often a bluish discoloration of the overlying skin. Most are soft, doughy, and compressible. The controversy over whether these are true neoplasms or vascular malformations has not been resolved. Approximately 50% of hemangiomas will undergo spontaneous involution, particularly during the second and third years of life. Recurrence after superficial parotidectomy is unusual. Three characteristics of malignant neoplasms of the major salivary glands in children deserve emphasis: * Their biologic activity does not differ from that of there counterparts in adults * They may be of epithelial or mesenchymal origin. * Well-differentiated mucoepidermoid carcinoma is the malignant neoplasm usually observed. * Mucoepidermoid and acinic cell carcinoma together account for approximately 60% of malignant salivary neoplasms in children. PRINCIPLES OF TREATMENT FOR PAROTID TUMORS: The University of Virginia has drawn up the following treatment protocol, based on the factors which influence survival. Patient are categorized into one of four groups: Group 1: This includes T1 and T2N0 low-grade malignancies(mucoepidermoid low-grade and acinous). Excision of tumor with a cuff of normal tissue is recommended. This usually requires total parotidectomy. Regional lymph nodes should be evaluated at the time of surgery. The facial nerve is preserved. Group 2: This includes T1 and T2N0 high-grade malignancies(adenocarcinoma, malignant mixed, undifferentiated, and squamous). Total parotidectomy with excision of digastric nodes and preservation of facial nerve is recommended. If the nerve is involved, it is resected back to clear margins on frozen section, and immediately grafted. All patients receive wide field XRT to include the upper-echelon nodes. Group 3: This includes T3N0 or any N+ high-grade cancers and recurrent cancers. Radical parotidectomy with sacrifice of facial nerve and modified neck dissection is recommended for N0. Radical neck dissection is recommended for N+ necks. If there is evidence of facial nerve involvement into the mastoid, the nerve must be followed until negative margins are obtained. Primary nerve grafting is recommended. Post-operative XRT is given to a wide field, from skull base to clavicle. Group 4: This includes all T4 tumors. In addition to radical parotidectomy and neck dissection, surgery may sometimes have to include resection of the masseter muscle, buccal fat pad, skin, mandible, ear canal, mastoid, or other involved structures. Post-operative XRT is routine and the facial nerve is grafted. INDICATIONS FOR POST-OPERATIVE RADIATION THERAPY: * High-grade tumors * Gross or microscopic residual disease * Tumors involving, or close to, the facial nerve * Recurrent disease * Documented lymph node metastasis * Extra-parotid extension * Deep lobe cancers * All T3 and T4 cancers COMPLICATIONS OF PAROTID SURGERY: * Facial nerve injury * Hematoma. Generally related to inadequate hemostasis at the time of surgery. Treatment involves evacuation of the hematoma and hemostasis. * Gustatory sweating (Frey's syndrome). This is a complex of symptoms including localized facial sweating and flushing during mastication. It may be a result of aberrant regeneration of nerve fibers from the postganglionic secretomotor parasympathetic innervation to the parotid occuring through the severed axon sheaths of the postganglionic sympathetic fibers that supply the sweat glands of the skin. It usually presents several months after surgery. The reported incidence of this complication varies from 10 to 100 per cent. It is usually a very minor problem but may require treatment. Options include topical application of 1% glycopyrolate lotion, fascia lata transfer, sternocleidomastoid muscle flap interposition, or tympanic neurectomy. * Salivary fistula. This is a rare complication and usually responds to treatment with pressure dressings. It usually presents as an opening in the suture line below the lobule ofthe pinna. * Wound infection ----------------------------------------------------------------------------- BIBLIOGRAPHY 1. Bull, T.R., A Color Atlas of ENT Diagnosis, Marion, Merrell, and Dow Inc. P 237. 2. Byun, Y. S., Fayos, J.U., Kim, Y. H.: Management of Malignant Salinary Gland Tumors., Laryngoscope, 90: 1052-1060, 1980 3. Cummings, C., editor, Otolaryngology Head and Neck Surgery, Vol. 2, 1987. 4. Dawson, A. K., Orr, J. A.: Long-term Results of Local Extension and Radiotherapy in Pleomorphic Adenoma of the Parotid., Int. J. Radiation Oncology Bio. Phys., 11: 451-455, 1985. 5. English, G. M., editor, Otolaryngology, J. P. Lippincott Company, Philadelphia, Vol 5, Ch 30-31, 1990. 6. Fulmer, R. P. and Stiernberg, C. M., Salivary Gland Neoplasms, Grand Rounds Presentation, UTMB, November 28, 1990. 7. Huang, R. D., Pearlman, S., Friedman, W. H., and Loree, T., Benign Cystic vs Solid Lesions of the Parotid Gland in HIV Patients. Head and Neck, Nov/Dec 1991 8. Kay, L.W. and Haskell, R., Color Atlas of Orofacial Diseases., Yearbook of Color Atlas Services., p 151, 161, 173, 1971. 9. Preston-Martin, S., Brain and Salivary Gland Tumors Related to Prior Dental Radiography. JADA 1990, 120: 151-157. 10. Seifert. G.: Salivary Glands., Diseases of the Head and Neck, An Atlas of Histology. 1987., Ch 7. 11. Spiro, R. H., Diagnosis and Pitfalls in the Treatment of Parotid Tumors. Seminars in Surgical Oncology, 7: 20-24, 1991f ---------------------------------END-----------------------------------------