Spectrum of Salivary Gland Disorders in a Tertiary Care Hospital : A Four Year Experience

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Salivary gland tumors are a heterogeneous group of neoplasm in the head and neck region. The major salivary glands are parotid, submandibular and sublingual, while minor salivary glands are located throughout submucosa of the upper aerodigestive tract with the maximum amount on the palate. Benign and malignant both can develop in all salivary glands. Although salivary gland tumors are less than 1% of all the tumors, however, the prevalence of these reported in the literature differs.

Salivary gland tumors constitute 2% to 4% of all the head and neck tumors. The prevalence of salivary gland tumors is reported to be from 0.4 to14 cases per anum per 100,000 population across the globe. While the prevalence of malignant salivary gland range from 0.4 to 2.6 per 100,000 population per anum. Among all the salivary gland disorders the commonest benign and malignant tumors are pleomorphic adenoma and mucoepidermoid carcinoma, respectively.

About 80% involves parotid glands, while 10% to 20% occur in submandibular and sublingual glands incidence wise. Approximately 80% of benign tumor of parotid glands is a pleomorphic adenoma.1 The cause of these tumors is still unknown; probably ionizing radiation, vitamin A deficiency, tobacco, prolonged exposure to sunlight, and chemotherapy may contribute to the development of these disorders. A longstanding lump is the presenting features of benign salivary gland tumors, while malignant tumors can present with a rapidly growing lump, pain, facial nerve palsy, trismus, fistula formation, skin involvement, cervical lymphadenopathy and weight loss.

Malignant parotid tumors may invade facial nerve in about one-third of cases, while malignant tumors of submandibular and sublingual glands may involve hypoglossal nerve, followed by trigeminal and facial nerves. Embryologically salivary glands develop as a result of initial thickening of the epithelium of the stomodeum, whereas submandibular and sublingual glands develop from endodermal germ layers3, while parotid gland develops from oral ectoderm. It is a diagnostic dilemma for histopathologist on one hand and challenging task for its classification on the other hand, due to the complexity and rarity of these disorders. In 1972 World Health Organization (WHO) published the first classification of salivary gland tumors, which has been amended so many times in last 4 decades.

The diagnosis of salivary gland disorders can be achieved with clinical features complemented with fine needle aspiration cytology, ultrasonography, magnetic resonance imaging, and computed tomography confirmed by a histopathological study of the specimen. However sometimes fine needle aspiration cytology alone cannot distinguish between benign and malignant tumors. Benign salivary gland tumors of parotid glands are treated by superficial parotidectomy, while benign submandibular gland tumors are excised totally, followed by observation for any recurrence. Treatment of malignant salivary gland tumors is total excision of the primary tumor along with the removal of the surrounding involved tissues, plus neck dissection followed by chemo-radiotherapy. The incidence of complications especially facial nerve damage is common in malignant tumors due to the close relationship of nerve with the gland.

As salivary gland tumors are common in our Pakistani society and sizeable cases are frequently presenting to our surgical outpatient departments, which are admitted and treated properly. So the purpose of this study was to look into demographic, clinical and histopathological features of salivary gland disorders. This cross-sectional study of 4 years (January 2013 to October 2017) was carried out in the Department of surgical unit 2, Fatima Jinnah Medical University, Sir Ganga Ram Hospital Lahore. After getting approval from the hospital ethical board, all patients with salivary gland disorders were included. Well informed written consent was taken from each patient explaining risks, benefits, an associated complication of the surgical procedure, the prognosis of the disease and about the publication of photographs if needed. All patients were evaluated in terms of detailed history, through local, oral cavity and systemic examination complemented by relevant investigations especially fine needle aspiration cytology (FNAC) of the swelling, ultrasonography and in certain suspicious cases, CT scans of head and neck with IV contrast were also done. Every swelling was assessed for its size, duration, transillumination, fluctuation, consistency, bimanual palpation, lymphadenopathy, skin and neurological involvement. After getting a diagnosis of the lesion based on clinical examination, radiological investigation and FNAC, the surgical procedure was performed accordingly. The specimens were examined by a histopathologist to confirm the disease. The data were analyzed through SPSS version 20.

In this study, 58 patients were included with a mean ± SD age of 34±1.4 years (age range 15–80 years). Males were 23(39.7%) and females were 35(60.3%) with a male: female ratio of 1:1.52. Most of the patients presented in 2nd and 3rd decades (60.3 %, 35). And out of those 35 patients in this age group, pleomorphic adenoma was the commonest histopathological finding (58.0%, 29), followed by mucoepidermoid carcinoma (50%, 2). (Table 01). Regarding the clinical features of salivary gland disorders, the swelling was the commonest (100%) presentation with a mean duration of 2±2.2 years. Most of the swellings (87.9%, 51) were firm on palpation and slow growth of the swellings was noticed in most of the patients (72.41 %, 42). Other features found were a pain, facial nerve palsy, fixity, skin involvement, transillumination, and cervical lymphadenopathy, in 17.2%, 1.7%, 3.4%, 3.4%, 3.4%, 3.4%, respectively (Table 02). Overall benign salivary gland disorders were 54 (93.1%), and malignant were 4(6.9%). Among all benign disorders, 50 cases (86.2%) were benign tumors, while 2 (3.7%) were inflammatory and two cases proved to be benign cysts. Overall benign tumors were noticed in parotid glands followed by submandibular glands. No tumor was found in sublingual glands. Among the benign, pleomorphic adenoma was the commonest histopathological finding (95.55%) in parotid glands followed by submandibular (63.33%). The overall incidence of malignancy was common in submandibular glands (18.18%) 2, followed by parotid glands (4.5%) 2. Among the malignant tumors, mucoepidermoid carcinoma was the commonest histopathological finding (6.9%) 4. (Table 3).

This prospective cross-sectional study of 4 years was carried out in the Department of Surgery, Fatima Jinnah Medical University, Sir Ganga Ram Hospital Lahore. The study was carried out on 58 patients suffering from salivary gland disorders presenting to our surgical outpatient department, from January 2013 to October 2017. All admitted cases were assessed by thorough history, physical examination, and relevant investigations. After performing relevant surgical procedures, specimens were examined by histopathology department.

In this study age range of the patients was from 15 to 80 years with a mean ± SD age of 34±1.4 year. Males were 23 and females were 35 with a male: female ratio of 1:1.52. Most of the patients presented in 2nd and 3rd decades (60.3%). The swelling was the commonest clinical feature with a mean duration of 2±2.2 years. Pleomorphic adenoma was the commonest benign tumor (86.2%), affecting parotid gland in 95.55% of cases. Mucoepidermoid carcinoma was the commonest malignant tumor (6.9 %) predominantly found in submandibular glands (18.18 %), followed by parotid glands (4.5%). No sublingual tumor was found in this study

Salivary gland disorders predominantly affecting middle age female population. Benign tumors are the commonly occurring salivary gland tumors. Pleomorphic adenoma is a commonly occurring benign tumor affecting predominantly parotid gland while mucoepidermoid carcinoma is the commonest malignant tumor of submandibular glands. Inflammatory disorder (Chronic sialadenitis) is also common in submandibular glands.