Various intra oral cystic lesions are encountered during routine dental check-up or reported by patients and is commonly observable finding during clinical practice. Sublingual epidermoid cyst is a type of benign subcutaneous cystic lesion, derived from the ectoderm, and is rare and develops beneath the tongue or floor of the mouth. Most of the time, these cysts are found asymptomatic, however are reported with discomfort or complications in a patient if they grow in size. Therefore, a thorough knowledge about the nature of sublingual epidermoid cysts is essential arriving at proper diagnosis and also to provide appropriate treatment. In this article, an extensive literature review of the cases reported so far using PUBMED electronic database search was performed to explore its characteristics, etiological features, symptoms, diagnosis, complications, treatment options and prognosis along with its bibliographic details.

Epidermoid cyst is a rare benign cystic lesion which is rarely seen in the floor of the mouth. Being a cystic malformation deriving from the ectoderm, they represent less than 0.01% of all the oral cavity cysts [1-3]. While relatively uncommon, these cysts can lead to various symptoms and may require meticulous diagnosis and treatment planning. In composition, they are filled with keratin, sebum, and other skin debris. As a result, they are considered a type of inclusion cyst [4].

Occurrence of epidermoid cyst are more frequent in the other part of the body like skin, ovaries, testicles (80%), head and neck region (1.6-6.9%) compared to intraoral appearance (0.01%) [2,3].  As their occurrence in the oral cavity is uncommon, there are less publications found in the dental journals especially in pediatric journals. Moreover, occurrence of these cysts in pediatric patients are extremely rare. Literature search revealed hardly countable number of publications and no publications in pediatric journals (Table 1) [3,5-11]. Moreover, it is evident that there is no bibliographic analysis carried out pertaining to this cyst apart from few simple narrative reviews. Therefore, the aim of the present article is to analyses the bibliographic details of the sublingual epidermoid cyst pertaining to its characteristics, etiological features, symptoms, diagnosis, complications, treatment options and prognosis in children. Such detailed bibliometric analysis contributes to the thorough understanding of occurrence of this uncommon lesion in pediatric patients providing insights into their management and the importance of meticulous diagnosis.

The detailed electronic database search was carried out using PubMed from 1992 till 2024 for a period of one week using key words (MeSh terms) like ‘sub-lingual cysts’, ‘intraoral cysts in children,’ ‘epidermoid cysts,’ ‘soft tissue lesions in oral cavity’ and ‘cysts in floor of the mouth’ in different combinations. Only relevant articles pertaining to sublingual epidermoid cysts and which are in English language were considered for evaluation. Those reported in the head and neck region or other parts of the body, other parts of the oral cavity were excluded from the review. Letter to editor and abstracts were also not considered for the evaluation.

Following the literature search, a total of 43 publications were selected (Figure 1). All publications were tabulated pointing the demographic factors like author, year of publication, age, gender of the patient, journal in which article is published, place of the case published, symptoms, location and treatment approach carried out in chronological order starting from new to old (Table 1) [1-45].

Table 1: List of published sublingual epidermoid cysts in the English literature retrieved through PUBMED search

Figure 1: Bibliometric analysis of Pediatric and total publications

A total of 60 cases have been reported from total 43 publications, in that majority publications were contributed from India (n=13) followed by Brazil (n=4), USA (n=3) and Turkey (n=3) (Table 1) (Figure 2). Maximum publications were reported in medical journals with only eight reports published in journals related to dentistry such as Journal of the Canadian Dental Association, Case Reports in Dentistry, Journal of Oral and Maxillofacial Surgery, National Journal of Maxillofacial Surgery, Annals of Maxillofacial Surgery, Journal of Clinical and Experimental Dentistry, Medicine Oral Pathology Oral Circum Bucal and Journal of Maxillofacial and Oral Surgery. Not a single publication was published in pediatric dental journals (Table 2).

Figure 2: Country-wise metric analysis about their contribution

Table 2: Bibliometric analysis of Journal’s contribution towards occurrence of Sublingual Epidermal cysts.

In the present bibliometric analysis about the domain occurrence of sublingual epidermal cysts, literature search was carried out using PUBMED electronic database from inception 1992 till December 2024 and the selected articles were tabulated (Table 1). Following the search, a total of 43 publications reporting total 60 cases have been reported occurring in the sublingual region of the oral cavity.

Evaluation of reported sublingual epidermoid cysts in pediatric patients revealed hardly nine cases in the English literature showing uncommon occurrence of these cysts during childhood or puberty (Table 1). Among these nine cases, six cases were diagnosed in female patients and remaining three in male patients. This finding was contrast to the previous reports showing male predilection found in adult cases [2,3,25]. However, some reports show there is no gender predilection for this cyst [12-15]. The age of the patients in children ranged from 11 months to 14 years old in this review. In case of adult patients, a wide age group is observed ranged from 15 to 87 years with mean age of 34 years in males and 29 in females [2,3]. Only in two cases symptoms like difficult in chewing and speaking was present and in remaining cases there were no symptoms present with the lesion.

Santos et al recently (2020) [3] evaluated the clinical and morphological features of both dermoid and epidermoid cysts of the oral cavity in their 48-year retrospective study in Brazil at an oral diagnosis reference center. Among 15.387 documented cases, only 4 (30.7%) of sublingual epidermal cysts were found and in that they found only one case of epidermoid cyst in an eleven-month-old female infant. Unfortunately, they have not mentioned the treatment approach done in this case.

In children, these cysts usually mimic or be mimicked by dermoid cyst or ranula in that region. It is very difficult to differentiate between plunging ranulas from plunging sublingual epidermoid cyst and pose a great diagnostic challenge as both of them exhibit very similar clinical features [12-14]. A ranula is a retention cyst of the sublingual salivary gland, characterized by unilateral transparent lesion occur in the floor of the mouth below the tongue. Even this is more common in children. Therefore, in differential diagnosis of large sublingual cysts, dermoid cyst and simple ranula should be considered. Using only radio imaging studies, it is not possible to distinguish between a dermoid, epidermoid cyst or a simple ranula. As three of them require different treatment strategies, it is important to differentiate one from the other. FNAC investigation guides in differentiating ranula from epidermoid or dermoid cyst. In addition to this, MRI provides a valuable information of the cyst location thereby helping in selection of appropriate surgical approach [19,27]. In the present case, there was a diagnostic dilemma regarding plunging ranula or sublingual epidermoid cyst as both are common in the midline of the oral cavity in the anterior portion of the sublingual space. When both these swellings in the floor of the mouth dissect through the mylohyoid muscle and produce swelling within the neck, they are referred to as plunging sublingual epidermoid cyst or plunging ranulas. But following histopathological examination, a final diagnosis of plunging sublingual epidermoid cyst was made. Therefore, for proper diagnosis and to rule out from different lesions, a histopathological examination is always mandatory [30,31].

The clinical appearance of these lesions in the oral cavity depends on their size, as well as their anatomical locations. They vary in size from a few millimeters to a few centimeters and literature shows few cases of giant cysts [20,30,32]. In one case it measured 7 cm and, in another case, it measured 13 cm. Lyngdoh et al [1] published a giant sublingual epidermoid cyst which measured 13×13 cms, with visible Wharton’s duct openings on both the sides. Radiographic examination revealed even a grossly enlarged mandible in this case. Therefore, early detection and diagnosis of all cystic lesions in children is highly essential [46].

Regarding review of treatment approach, in four cases intraoral approach and in remaining cases extra oral approach was used. In the present case, transoral approach was used. The intraoral approach is more appropriate for sublingual epidermoid cysts and small/medium sized lesions and has the advantage of no external visible scar [43]. However, it is associated with limited exposure and with higher morbidity due to damage to Wharton’s duct and other vital structures in the sublingual space. Transcervical approach is required for infra-mylohyoid cysts and large lesions which gives an optimal result.

Sublingual epidermoid cysts are rare in children but can present challenges when they become symptomatic. Understanding their characteristics, causes, symptoms, and available treatment options is crucial for healthcare professionals and individuals including pediatric dentist affected by these cysts. Early diagnosis and appropriate management contribute to a positive prognosis and improved quality of life for those with sublingual epidermoid cysts.