Distribution and Frequency of Salivary Gland Tumours: An International Multicenter Study.

BACKGROUND: Salivary gland tumours (SGT) are a relatively rare group of neoplasms with a wide range of histopathological appearance and clinical features. To date, most of the epidemiological studies on salivary gland tumours are limited for a variety of reason including being out of date, extrapolated from either a single centre or country studies, or investigating either major or minor glands only. METHODS: This study aimed to mitigate these shortcomings by analysing epidemiological data including demographic, anatomical location and histological diagnoses of SGT from multiple centres across the world. The analysed data included age, gender, location and histological diagnosis from fifteen centres covering the majority of the world health organisation (WHO) geographical regions between 2006 and 2019. RESULTS: A total of 5739 cases were analysed including 65% benign and 35% malignant tumours. A slight female predilection (54%) and peak incidence between the fourth and seventh decade for both benign and malignant tumours was observed. The majority (68%) of the SGT presented in major and 32% in the minor glands. The parotid gland was the most common location (70%) for benign and minor glands (47%) for malignant tumours. Pleomorphic adenoma (70%), and Warthin's tumour (17%), were the most common benign tumours whereas mucoepidermoid carcinoma (26%) and adenoid cystic carcinoma (17%) were the most frequent malignant tumours. CONCLUSIONS: This multicentre investigation presents the largest cohort study to date analysing salivary gland tumour data from tertiary centres scattered across the globe. These findings should serve as a baseline for future studies evaluating the epidemiological landscape of these tumours.

Biological warfare--an emerging threat.

As we approach the 21st century, there is an increasing worldwide awareness and threat regarding the use of biological warfare agents both for war and terrorist attack. Biological agents include microorganisms or biological toxins that are used to produce death in humans, animals and plants. They are characterized by low visibility, high potency, substantial accessibility and relatively easy delivery. Biological warfare agents are unconventional weapons that can be delivered by unconventional means like aerosol sprays, food and water contamination, conventional explosive munitions or by covert injections. Because of their concealed delivery, easy transportation and difficult identification they are readily adaptable for terrorist operations or to gain political advantages. The detection of such attack requires recognition of the clinical syndromes associated with various biological warfare agents. Diagnosis can be made on clinical grounds and on investigations. Protective measures can be taken against biological warfare agents. These should be implemented early (if warning is received) or later (once suspicion of agent use is made). After the confirmation of diagnosis emergency medical treatment and decontamination are performed in rapid sequence. Patients are then evacuated and specific therapy is given according to the agent involved. Appropriate emergency department and hospital response could significantly limit the morbidity and mortality of biological warfare agents.