ARTICLES

(Text of Smt. Radha Devi Memorial Oration delivered on 29^th December, 99 at Madurai during ASICON)

Salivary gland tumours are uncommon. They vary considerably in their site and manner of presentation. Variability in behavious exists even amongst histologicaly similar types and yet histological criteria are often poor prognostic indicator. Treatment should thus be planned individually.

INCIDENCE: Accounts for 650 deaths per year in the USA. In USA: 3 - 4% of all neoplasms of the Head and Neck. In UK: 40 cases per year. AT CRI, Varanasi; 1 - 4 new cases per year. Less than 1% of all registered malignancies.

CLASSIFICATION (WHO)

I. EPITHELIAL

1. Benign:

1. Pleomorphic adenoma
2. Monomorphic adenoma

• Adenolymphoma (Warthin's tumour)
• Benign lymphoepithelial tumour (Goodwin's)
• Oxyphilic adenoma (Oncocytoma)
• Basal cell tumour
• Others

B Malignant

• Acinic cell tumour
• Mucoepidermooid carcinoma
• Carcinoma in pleomorphic adenoma
• Adenoid cystic carcinoma
• Lymphoepithelioma
• Metastatic tumours.

II NON-EPITHELAL

• Lymphomas
• Haemangiomas
• Lymphangiomas
• Neurofibromas
• Lipomas

(Other classification of recent origin exit such as the one by Foote & Frazell and the AFIP one.)

AETIOLOGY: Largely unknown. Suggestion are:

• Epstein - Barr Virus
• Childhood irradiation
• Nutritional deficiencies
• U. V. Exposure
• Genetic

AGE & SEX DISTRIBUTION: Major salivary gland tumours:

Average age incidence:

Benign: 40 years

Malignant: 55 years

Male predominance in Warthins, Female predominance in Acinic cell tumours

SITE & DISTRIBUTION:

CLINICAL EXAMINATION

• Local Examination including bimanual examination
• Examination for nerve palsy

• Cranial nerves - VII, IX, XII, mandibular br of V nerve, Lingual
• Sympathetic chain

• Regional nodal examination
• Systemic examination

Features and symptoms of malignancy

• Unremarkable mass at the site of origin
• Mild intermittent pain
• Nerve involvement
• Dysphagia
• Skin ulceration
• Symptoms due to surrounding structure involvement
• Sudden rapid growth in previously slowly growing tumour

INVESTIGATIONS:

1. Biopsy

• FNAC - useful for preoperative evaluation of salivary swellings and for documenting of recurrent and metastatic disease
• Limitation:: pathologist should be familiar with it
• Accuracy - 90%. It is of special significance in our country where tuberculosis and metastatic SCC involving perisalivary lymphonodes are common
• Trucut - For parotid, submandibular glands
• Open - For minor salivary gland tumours

1. CT SCAN with contrast/3D reconstruction
2. MRI
3. Sialography
4. Gallium Scan

STAGING (UICC 1987):

T1 - <=2cm All Categories are divided into

T2 - >2-4 cm a) No extension

T3 - > 4-6 cm b) extension

T4 - > 6 cm

N1 - Ipsilateral single <=3 cm

N2 - Ipsilaterial single >3-6cm

Ipsilaterial multiple <=6cm

Bilateral contralateral <=6cm

N3 - >6cm

M0 - No distant metastasis

M1 - Distant metastasis

Mode of spread of malignant salivary tumours:

• By expansion
• By local infiltration
• By recurrence - multiple nodules in the gland and overlying skin
• By perineural infilration - characteristic of adenoid cystic tumours
• By lympathics

TREATMENT MODALITIES:

SURGERY

• Superficial parotidectomy
• Total parotidectomy
• Submandibular triangle dissection
• Wide excision of minor gland tumours
• Functional or radical neck dissection

RADIOTHERAPY PROGNOSTIC FACTORS:

• Location of primary tumour
• Extent of primary disease
• Lymph nodal status
• Adequacy of surgery
• Histopathology

POST OPERATIVE COMPLICATIONS:

Early:

• Infection
• Hematoma
• Injury to nerve - VII, XII, Lingual, Mandibular br.of V.
• Injury to the VII N. ( neurapraxia) can occur even after adequate exposure and may take upto 6 months to recover. If detected at surgery, primary suture or grafting can be taken ( (Gr. Auricular, sural N.)

Other options

• Fascia lata sling
• Muscle transfer using temporalis, masseter etc.
• Lateral tarsorraphy
• External salivary fistula
• Local sensory loss

Late:

• Recurrence
• Frey's syndrome
• Ocular damage
• Factitious damage to pinna
• Markus Gunn phenomena

INDICATIONS FOR POST OPERATIVE RADIOTHERAPY

• As an adjunct to surgery
• As a palliation in inoperable tumours

.a In benign mixed tumours:

• Presence of residual disease
• After excision of recurrent tumours

.b In malignancy

• Recurrent tumours
• Positive margin after surgery
• Narrow margin on facial nerve
• Multiple nodal metastasis
• Perineual invasion
• Submandibular tumours

PRINCIPLES OF TREATMENT FOR PAROTID AND SUBMANDIBULAR CARCINOMA

TUMOUR TYPE FOR TREATMENT GROUP

The CRI Experience in Managing Salivary Gland Tumours

I Frequency:

II Patients presenting first time treatment: 16 (Group I)

Patients presenting after treatment outside 12 (Group II)

III Treatment approach

IV Malignant tumours: Treatment with Radiotherapy alone. (N=8)

CONCLUSIONS:

Salivary gland tumours though less common, are encountered in our country. Problems in their management are largely related to the facial nerve. A proper consent should thus be taken from the patient before embarking on surgery for these tumours and should be managed preferably at centers where expertise to handle complications resulting from surgery can be tackled in a proper and judicious way.

REFERENCES:

1. Oxford Textbook of Oncology Vol. I 1995
2. Archives of Otolarygology - Head & Neck Surgery Col 15 March, 1989
3. Journal of Surgical Oncology 45:52-55 (1990)
4. American J. Surgery Vol. 164:623-628 ( 1992)
5. Principles of Surgery, 7^th Ed. 1999 Vol. I Schwartz etal Ed.
6. Comprehensive Text Book of Oncology. Moosa et al Ed. (1991)
7. Scott- Brown's Otolaryngology Sixth Ed. 1997 Butterworth Heinemann