Patterns of salivary tumours at a university teaching hospital in Kenya

Abstract

Salivary gland tumours (SGT) are rare, comprising about 5% of head and neck tumours with a higher incidence reported in the western compared with the African centres. There are few studies on SGTs that have been conducted in Africa. A descriptive retrospective study was done to describe the demographic characteristics, site distribution and histological patterns of SGT at a University teaching hospital in Kenya over a 12-year-duration. There were 132 SGTs out of 2426 biopsies of head and neck tumours, the age range was between 8 to 80 years (mean = 43.6 yrs) and the modal age was 50 yrs. The percentage of tumours arising from minor salivary glands (MiSG) (67%) were twice than that from the major salivary glands (MaSG) (33%). The sites most affected for the Misg was the palate and for the MaSG was the submandibular gland. Pleomorphic salivary adenoma (PSA) (40.2%) was the most common benign SGT while adenoid cystic carcinoma) (ACC) (20.5%) was the most frequent amongst the malignant type. The overall male:female ratio was almost 1:1. However, there were more females than males with benign SGTs, whereas an equal gender distribution was noted in malignant SGT. Benign and malignant SGT occur at a younger age. MiSGs of the palate were most frequent site of tumour and the least frequent is the sublingual gland. More than 50% of SGT were malignnant and hence any SGT should raise a high index of suspicion.

Pattern of Salivary Gland Tumour in Sokoto, North-Western Nigeria

“…But in our study, the minor salivary glands with 63 (61.2%) cases, was the commonest site of the SGTs that is similar to findings in other studies [6] [21]. A possibility of racial variations existing in the clinico-pathologic distribution of SGTs, with Africans having less proportion of SGTs in the parotid gland, but more proportion occurring in the minor salivary and submandibular glands when compared with white populations in Table 2.…”

“…Poverty, illiteracy, religious faith and low life expectancy may be proffered as some of the reason for the fewer number of elderly SGT patients seen in African studies. Unlike other studies that have reported female preponderance in SGTs [6] [9], our finding was that of male dominance and is similar to the findings of Silas et al [14] in North-Central Nigeria, who attributed this to cultural practices which refuses females from attending hospitals alone without permission from their husbands. In addition however, most women in northern Nigeria are not gainfully employed, and this causes serious problem to the family when it comes to payment of hospital bills.…”

“…Contrary to western reports that the submandibular SGTs had more malignant tendency, our study revealed a more benign tendency of the submandibular SGTs. However, our findings further reiterate the assertion that pa-rotid SGTs are more likely to be malignant in African populations [6] [7].…”

“…This study reviewed 103 cases of SGTs within a five-year period, with patients' ages ranging between the 1 st to 7 th decades of life with a peak at the 4 th decade, similar to other African studies [6] [11]. Over 70% of the patients under review were between 21 -60 years.…”

“…According to the World Health Organization (WHO), global incidence of salivary gland tumors is about 0.4 -13.5 cases per 100,000-population annually [5]. These tumors occur mainly in the parotid, submandibular, and minor salivary glands; while the sublingual gland is rarely affected [6]. Most studies in Africa have noted benign tumours especially the pleomorphic adenoma as more common than the malignant ones, particularly the muco-epidermoid and acinic cell carcinoma [7]- [9].…”