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date, most of the epidemiological studies on salivary gland tumours are limited for a variety of reason including being out of date, extrapolated from either a single centre or country studies, or investigating either major or minor glands only.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.

The range of lesions seen in Saudi geriatric patients were similar to those reported for other parts of the world, although the lesions were more similar to those reported from developing countries. The very high rate of oral cancer, however, is expected to take the majority of the resources allocated to geriatric oral health care, except if a strong, population-based prevention program is initiated immediately.

Most MEC of minor salivary glands appear to be low-grade tumors. It is conceivable that some grading methods (Brandwein and modified Healy) may lead to an unnecessary escalation of management methods in these tumors. The MSKCC method may have emphasized some parameters which may not have much importance in minor salivary gland MEC. The AFIP method appears to be the most appropriate to use for the grading of minor salivary gland MEC. Further studies are required to confirm or disprove this finding.

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare malignant neoplasm that has an exquisitely exclusive affection to the jawbone. It is defined as squamous cell carcinoma arising within the jaw and developing from residual odontogenic epithelium or from a preexisting odontogenic cyst or tumor. The solid-type of this tumor is a central jaw carcinoma arising de novo and has no initial connection with the oral mucosa. Herein, we report a case of solid-type PIOSCC involving the mandible in a 37-year-old male patient elucidating its histopathological and imaging findings. The patient underwent surgical resection followed by post-operative adjuvant radiotherapy. The close 2-year follow up of the patient revealed neither locoregional nor distant metastasis.

Peripheral dentinogenic ghost cell tumor is a rare tumor with only 24 cases previously described in the English literature. The majority of cases have been reported to occur in the anterior part of the jaws. A case occurring in posterior (molar region) of the mandible in a 75-year-old edentulous woman is reported. The patient presented with a nodular swelling in the left mandible that showed erosion (saucerization) of the underlying bone radiographically. On microscopy, the tumor showed mainly solid epithelial islands resembling ameloblastoma in fibrous connective tissue. The islands were associated with ghost cells and dysplastic dentin. This report includes the clinical, radiographic, and microscopic features of the patient, in addition to the review of the English literature on the tumor.