Malignant Salivary Gland Neoplasm-clinicopathological Study

Salivary gland neoplasm constitute about 10% of all head & neck neoplasm which represent 3% of all neoplasm of the body. In this study 50 patients of salivary gland neoplasm were studied to observe the frequency & clinicopathological pattern. Among 50 cases, 39(78%) were parotid neoplasm, 4 (8%) were submandibular neoplasm and 7 (14%) were minor salivary gland neoplasms. Among the parotid neoplasms, 13 (33.33%) were malignant neoplasms. Whereas in the submandibular neoplasm 2 (50%) were malignant neoplasms and for minor salivary glands tumour 4 (57.14%) were malignant neoplasms. Forty nine cases undergone some form of surgery. Most of them were treated by superficial or total conservative parotidectomy or radical parotidectomy/ submandibular gland excision with or without block dissection. Key word: Salivary gland neoplasm, Adenoid cystic carcinoma, Facial nerve. 1. OSD, DG Health, deputed in BSMMU, Dept. of Otolaryngology-Head & Neck Surgery, BSMMU, Dhaka. 2. Associate Professor, Dept. of Otolaryngology-Head & Neck Surgery, BSMMU, Dhaka. 3. Assistant Professor, Dept. of Otolaryngology-Head & Neck Surgery, BSMMU, Dhaka. Introduction Cancer is one of the few disease still unconquered inspite of relentless efforts of the scientists all over the world. It causes about 12% deaths throughout the world.1 Neoplasm of the salivary gland is an ancient disease. It was first described by kareka in 1952. Throughout the world salivary gland neoplasm constitute about 10% of all head and neck neoplasms which represents 3% of all neoplasm in the body.2,3 Among the salivary gland neoplasms, parotid gland is the commonest site (about 75%)4, of these almost 80% are benign and 80% of benign tumours are plemoriphic adenomas.5 Submandibular gland is the second most common site of neoplasm constituting about 10 to 19%.6 Tumours of the sublingual and minor salivary glands are uncommon representing about onetenth of all neoplasm of salivary glands.7 It is important to have a proper broad based study of neoplasm of salivary gland to find out incidence of malignancy among salivary neoplasms. There are several histological types of malignancy affecting the salivary glands, of which being relatively lower in the parotid gland. Malignancy is far more frequent in the submandibular, sublingual and minor salivary glands. So far it is known, a complete study for frequency of malignancy in salivary gland neoplasm was not carried out previously in our country. This study was carried out to find the frequency of malignancy among salivary gland neoplasms, their histological types, age and sex distribution of the patient, probable aetilogical factors, symptoms, specific site of malignancy and compare the findings with those of previous studies carried out in our country and abroad. Materials and Method : This was a cross sectional study carried out in the department of Otolaryngology-Head & Neck Surgery of BSMMU & DMCH during the period of September, 2006 to March, 2007. Study has been carried out on a total number of 50 patients of salivary neoplasm of different age group. Data were collected by taking history, physical examination & necessary investigation. Aims and Objectives 1. To see the frequency of malignancy among salivary gland neoplasms, 2. To see the demographic features of the cases.


Introduction
Cancer is one of the few disease still unconquered inspite of relentless efforts of the scientists all over the world.It causes about 12% deaths throughout the world. 1 Neoplasm of the salivary gland is an ancient disease.It was first described by kareka in 1952.Throughout the world salivary gland neoplasm constitute about 10% of all head and neck neoplasms which represents 3% of all neoplasm in the body. 2,3ong the salivary gland neoplasms, parotid gland is the commonest site (about 75%) 4 , of these almost 80% are benign and 80% of benign tumours are plemoriphic adenomas. 5Submandibular gland is the second most common site of neoplasm constituting about 10 to 19%. 6Tumours of the sublingual and minor salivary glands are uncommon representing about onetenth of all neoplasm of salivary glands. 7 is important to have a proper broad based study of neoplasm of salivary gland to find out incidence of malignancy among salivary neoplasms.There are several histological types of malignancy affecting the salivary glands, of which being relatively lower in the parotid gland.Malignancy is far more frequent in the submandibular, sublingual and minor salivary glands.So far it is known, a complete study for frequency of malignancy in salivary gland neoplasm was not carried out previously in our country.This study was carried out to find the frequency of malignancy among salivary gland neoplasms, their histological types, age and sex distribution of the patient, probable aetilogical factors, symptoms, specific site of malignancy and compare the findings with those of previous studies carried out in our country and abroad.

Materials and Method :
This was a cross sectional study carried out in the department of Otolaryngology

Results
The present series of 50 cases included the varieties of salivary gland tumours both benign and malignant.But no tumour of sublingual gland was found at that time and likewise does not included in this series.Out of all cases, parotid tumours (both benign and malignant) was 39 (78%), submandibular tumour was 4 (8%) and minor salivary gland was 7 (14%) in numbers.
Carcinoma was common in older age groups and rare in children but benign neoplasm in children and adolescent was not so uncommon.Highest incidence of tumours were found in 5 th decade (50-60 yrs) of life as found in 26% of cases.Next common age incidence have been noted in 3 rd decade of life 22%.
Most of patients (n= 24) were admitted in hospital within 4-8 years of their first symptoms.The second largest group of patients (n= 13) were admitted within 2-4 years of appearance of 1 st symptoms.
The most common and constant presentation was swelling.It was found in all of the cases i.e.100%.Pain was important symptom of malignancy.Overall 13 patients had pain, out of which 9 in parotid gland malignancy, 1 in submandibular and 3 in minor salivary gland malignancy.Facial nerve paralysis was found in 3 cases, all were in parotid gland malignancy.There were 5 cases who showed lymphatic metastasis 3in parotid malignancy and 2 in submandibular gland malignancy.

Age in years
No of case Percentage 10-20 yrs.
Among the submandibular salivary gland neoplasms benign tumour was 2 (50%) in this series compared to 48.2% in Evans and Cruickshank (1970).Benign tumours of minor salivary gland in this study 3 (42.86%)and malignant was 4 (57.14%)compared to that of other study which shows malignancy rate as 55.0%. 7Fifty percent of submandibular gland neoplasm was malignant & that for parotid gland was 33.33%.Incidence of malignancy was higher in submandibular gland which conforms with other studies. 2,19ong the parotid malignancy, 10(25.64%)were mucoepidermoid carcinoma & 3(7.70%) were carcinoma in pleomorphic adenoma.Mucoepidermoid tumours in this study was the commonest malignant tumour although other studies revealed it as the second most common malignant tumour. 2,18oplasm of salivary gland may occur at any age, Marshall and Miles (1974) showed malignant tumours usually appear in later age group but may be seen in the adolescents.In this study highest number of patients were in the 5 th decade (26%) which correlate with other studies. 2,7garding the sex distribution of different neoplasms, benign parotid tumours was more common in male (M:F= 1.8:1).Malignant parotid neoplasms was also more common in male (M:F= 1.8:1).All of benign submandibular salivary gland neoplasms were male.Among the malignant submandibular neoplasms, 50% were in male.Among the benign minor salivary gland tumour, 2 (66.67%) were male and 1(33.33%) was female.Out of 4 malignant tumours of the minor salivary gland 50% was male.In this study for both benign and malignant neoplasm, male was the predominant sex although other studies experienced slight female preponderance. 2,5,7e benign tumour generally have no pain or other distressing symptoms for which they do not care for it.Moreover they fear for the operative treatment.In under developed countries like us, due to poor socioeconomic conditions and non availability of modernized hospital facilities nearby-patient often report to local quackes and village doctors for their treatment before attend to a concerned specialist, for this reasons patient often reports late and sometimes with complication of the disease.In present series, most patients reported-within to 4 to 8 years of the disease.
In present series, all the cases presented with swelling.Size of the swelling in most pleomorphic adenoma were more than 2 cm and malignant tumours varied between 2 to 4cm.Patient with longer duration & larger swelling presented in more advanced stage.Most of the patient of malignant tumours admitted in the hospital at stage-3 is supported by others. 18garding investigation in present series, FNAC was done in all 50 cases (100%), out of which 44(88%) was positive, 3 cases (6%) was false positive and 3 cases (6%) was doubtful results.Post operatively 49(98%) cases were confirmed by histopathological examination.
Forty-nine patients in this series were subjected to treat by some forms of surgery.Most of them were treated by superficial or total parotidectomy/ submandibular gland excision ± block dissection, partial maxillectomy (in minor salivary gland tumour) + radiotherapy.Only one case was inoperable and was treated by radiotherapy.

Fig.- I :
Fig.-I: Overall malignancy rate among salivary gland neoplasm

Table - V
Duration of symptom before admission into Hospital