In general, salivary gland diseases can be subdivided into neoplastic and non-neoplastic diseases. The latter category includes different diseases that pose a diagnostic and therapeutic challenge to the clinician because of their closely similar clinical presentation despite different etiologies such as reactional inflammatory processes, metabolic and immune disorders, infections, and iatrogenic responses. Thus, clinical knowledge of oral lesions, as well as the determination of aspects related to the etiopathogenesis of these lesions, is necessary for the correct diagnosis and for the indication of appropriate treatment [16].
When located on the ventral tongue, the differential diagnosis with lymphangioma must be considered. de Camargo Moraes et al.[19] state that mucocele of the gland of Blandin-Nuhn (ventral tongue) should not be considered rare. In their series, this type of mucocele was the second most frequent.
Lesions located in the soft palate and retromolar region are rare, but in the latter case the differential diagnosis with mucoepidermoid carcinoma should be considered.
Among the non-neoplastic pathological processes affecting the minor salivary glands, mucoceles are the most common in children and young adults, a fact probably related to the higher frequency of injuries that result in extravasation of saliva to the adjacent connective tissue [11].
In agreement with similar studies reported in the literature, in the present investigation 75.85% of the cases were diagnosed during the first and second decades of life, 49.42% of them during the second decade of life. Two cases were diagnosed in newborns. Jones et al [9], analyzing 4406 children ranging in age from 0 to 16 years over a period of 30 years (1973-2002), observed 735 (16.68%) cases of mucoceles.
In the present study, most patients (60.12%) were females, in agreement with studies showing almost 70% prevalence of mucocele in women [17]. In contrast, Mathew et al. [20] describe a prevalence of mucocele in 0.16% of the population studied and the lesion was found only in males. Cataldo and Mosadomi [12], studying 594 cases between 1958 and 1969, observed no gender preference. As regards race, the lesion was more common in white subjects (124; 71,68%) in accordance to de Camargo Moraes et al. [19].
The most common location of mucoceles is the lower lip. This may be related to the trauma exerted upon the lip, as a result of teeth spatial distribution [3, 11]. In the present study, mucoceles were observed on the lower lip in 78% of the cases, all presenting a history of trauma. Less frequently involved regions included the ventral tongue, floor of the mouth (ranula), hard and soft palate, buccal mucosa, and lingual frenum.
Mucoceles are more frequently treated by surgical excision of the lesion and careful dissection of the adjacent minor salivary glands affected [11, 17]. However, recurrence can occur and a new surgical intervention taking the above mentioned care is necessary [11].
In the case of ranulas, treatment consists of surgical removal of the sublingual gland and/or marsupialization. Marsupialization may be performed before definitive excision of the gland in an attempt to permit the formation of an intraoral fistula through which saliva is excreted. This approach requires the removal of the roof of the lesion in order to permit reestablishment of the communication between the gland duct and oral cavity [11].
Yagüe-Garcia et al. [3] compared the results obtained after treatment with scalpel versus CO2 laser. Authors concluded that CO2 laser ablation is rapid and simple. They had postoperative complications and recurrence in the cases treated with conventional surgery. It is important to emphasize that the removed specimen must be microscopically evaluated to confirm the diagnosis, regardless of the technique used [3]. Prognosis is excellent.