## 3 Results  
_Clinico-Pathologic Characteristics of New Case Series of Intraoral Common Blue Nevi_  
Table 1 shows the clinico-pathologic characteristics of eight new cases of intraoral blue nevi. Accordingly, the mean age at diagnosis was 32.3 years within an age range of 19-52 years. In the present series, intraoral common blue nevi predominantly affected females, with a male to female ratio of 1:4. All lesions detected were single lesions amounting to less than 1 cm in size, while all lesions were identified on the palate (Figure 2). No raised swelling was observed in any of the lesions, although Figure 2 shows that the blue nevus is present with inflamed minor salivary gland duct openings in the background, which may have indirectly contributed to the slightly raised presentation. The colour of the lesions varied from blue to black. All nevi included in the present series were single lesions that did not present with recurrences or undergo a malignant transformation after being followed up for a minimum of 4 years and up to 15 years (Table 1). In the present series, the majority of the lesions were clinically identified as nevi (6/8), with a single lesion each carrying a clinical impression of an amalgam tattoo and melanotic macule. Microscopically, all lesions showed a submucosal proliferation of elongated spindle-shaped cells, with the majority of the cells containing melanin pigment within the cytoplasm (Figure 3a,b). All lesions contained varying amounts of melanophages. No cellular atypia or mitotic activity was noted. None of the DBN reported in this series was amelanotic in presentation or was evident in a background of densely sclerosed stroma. The melanocytic origin of the cells was confirmed with immunohistochemical investigations with an S-100 antibody (Figure 4a,b). Figure 3: (**a**) Photomicrograph exhibiting pigmented dendritic nevus cells in the submuc (HE) \(\times 10\). (**b**) Photomicrograph exhibiting pigmented dendritic nevus cells in the submuc (HE) \(\times 40\). A few nevus cells are highlighted in (**b**) with five pointed stars. Figure 4: (**a**,**b**) Immunohistochemistryistochemically stained section to show the origin of the nevus cells (S-100) \(\times\)10; 40. Note: all S-100-positive nevus cells are stained in a golden brown colour. Table 2 shows the distribution of OMN reported in five published studies and the present study. Out of the 521 OMN reported, the common blue nevi accounted for 25.7% (134/521) of the cases reported and were the second most common lesions reported in all case series [9; 10; 11; 12; 13; 14; 15; 16]. The most common lesions among OMN were submucosal/intramucosal nevi, which accounted for 61.5% (315/512) of the cases. The literature review-based clinicopathologic comparison was performed with DBN and intramucosal nevi as the remaining nevi were not observed in considerable amounts for meaningful statistical comparison. Accordingly, when considering both intramucosal and intraoral DBN, both may occur at any age, although the majority have been shown to occur in adults. In elderly patients, DBN are more common (32%) compared to intramucosal nevi (20%). Both lesions show a female predilection; however, a lack of relevant information in some references regarding gender distribution precludes definitive conclusions [9; 16]. With respect to the site of occurrence, the most significant observation is the fact that DBN show a predilection to occurring at the hard palate compared to other mucosal sites. On the other hand, intramucosal nevi do not show an overwhelming predilection to the hard palate and may occur in all mucosal sites including in keratinized and non-keratinized mucosal surfaces (Table 3).