Oral leukoplakia in the Sudan: clinicopathological features and risk factors

Abstract

Objectives: To analyse the clinical and histopathological features of oral leukoplakia (OL) in the Sudan, and to identify the risk factors associated with dysplastic and malignant changes.

Methods: Records of 117 cases with the diagnosis of OL at the Department of Oral Pathology in the period from 2010 to 2017 were reviewed.

Results: Of the 117 cases included in this study, 30 cases (25.6%) showed carcinoma in the initial diagnostic biopsy. The mean age at diagnosis was 59.8 years with a male/female ratio of 3.3:1. The lip (48.7%) and the gingiva (31.6%) were the predominantly affected sites. Multivariate regression analysis revealed that females were associated with 3.36-fold [95% confidence interval (CI), 1.36-10.76; P = 0.012] higher risk of malignant transformation compared with males. Verrucous leukoplakia was associated with 3.38-fold (95% CI, 1.12-10.19; P = 0.031) higher risk of malignant transformation compared with homogeneous leukoplakia. Exclusive Toombak dipping was the significant risk factor for the presence of dysplasia in OL (odds ratio, 9.35; 95% CI, 1.28-67.99; P = 0.027).

Conclusions: Clinical and histopathological features of OL were analysed and correlated. Toombak dipping was the significant risk factor for dysplastic changes, while female gender and verrucous leukoplakia were the factors associated with malignant transformation.

Keywords: Oral leukoplakia; Toombak; dysplasia; malignant transformation; risk factors.

Figure 1.

Clinical appearance of oral leukoplakia (OL) associated with Toombak dipping. (a) A superficial white lesion with no obvious thickness or roughness. (b) A white lesion located on the tongue showing a localised area of marked thickening and yellowish discolouration. (c) A diffuse white lesion extending on the lower lip and the gingiva associated with heavy thickening and grooving (verrucous). (d) An elevated white/yellowish lesion with marked thickening located on the buccal mucosa. Areas of erosions are noted at the margins.

Figure 2.

Histopathological changes of oral leukoplakia (OL) associated with Toombak dipping. (a) Hyperkeratosis with mild dysplasia. (b) Moderate dysplasia with multiple nucleoli extending to the middle third. Focal mitotic activity and broad rete ridges are noted. (c) Severe dysplasia. Pseudoepitheliomatous, hyperparakeratotic stratified squamous epithelium with dysplastic changes extended above the mid of the spinous layer.