SPECTRUM OF SALIVARY GLANDS LESIONS IN PAKISTAN: SIX YEARS DATA FROM THE LARGEST GOVERNMENT BASED REFERENCE LABORATORY OF SINDH, PAKISTAN

Objectives: To describe Pathology based spectrum of salivary gland-lesions in Pakistani population.
Methods: A six years observational study conducted at the Department of Histopathology, Dow diagnostic, reference and research laboratory (DDRRL), Karachi. All salivary gland lesions received at the laboratory during 2009-2014 were included in the study.
Results: A total of 370 samples were investigated. Of these, a total of 104(28%) were non-neoplastic and 266(72%) were neoplastic lesions. Out of 104 non-neoplastic lesions, 61 cases (58.6%) were of inflammatory origin and 43 (41.3%) were mucoceles. Out of 61 inflammatory lesions, chronic sialadenitis 48 cases (78.6 %) were the most common lesions. Submandibular gland was the most common effected site. For mucoceles, lower lip was the most common site.
Of the 266 neoplastic lesions, a total of 209 (78.5%) were benign while 57 cases (21.4%) were malignant. Pleomorphic adenoma was the commonest salivary glands benign neoplastic lesions, 188 (89.9%) followed by benign epidermal inclusion cysts as 6 cases (2.8%) and warthin’s tumour as 4 cases (1.9%). Parotid glands were involved in majority of pleomorphic adenoma cases, 132 (70.2) out of 188 cases.In malignant tumours, 21 cases (36.8%) of Adenoid cystic carcinoma were the most common salivary gland malignant neoplastic lesion, 18 cases (31.5%) were mucoepidermoid carcinoma as the second most common malignant lesion followed by 7 cases (12.2%) of Acinic cell carcinoma. Submandibular gland was the most common site in adenoid cystic carcinoma while parotid gland involved in majority of mucoepidermoid carcinoma.

Conclusions: Chronic sialadenitis was the most common non-neoplastic lesion, pleomorphic adenoma was the most common benign lesion and adenoid cystic carcinoma (followed by mucoepidermoid carcinoma) was the most common malignant lesion.