Excision of the mucocele of the lower lip with electrocautery: a case report

Moitra PN, Ambwani H, Singh Y, Gore D and Kumar R

Published on: 2024-06-01

Abstract

Mucocele is one of the common lesions of oral mucosa encountered that results from an alteration of minor salivary glands. Two histological types exist: extravasation and retention, with different causative factors such as trauma leading to severance of the duct with spillage of mucin into the adjacent connective tissue and obstruction, respectively. Clinically, they consist of a soft, bluish, and transparent cystic swelling that normally resolves spontaneously. Treatment frequently involves surgical removal, micro marsupialization, cryosurgery, steroid injections, and CO2 lasers. As mucocele is a common lesion and affects the general population, it is important to emphasize and share perspectives on it.

Keywords

Retention cyst; Extravasation phenomenon; Mucocele

Introduction

Developmental, inflammatory, ulcerative, neoplastic, etc. are various groups of lesions found in the lips. One of the most common lesions of the oral mucosa is mucocele, which occurs due to the buildup of mucous secretions due to trauma or lip-biting habits [1]. The lower labial mucosa is the most common site of occurrence of oral mucocele, as it is more likely to experience trauma [2]. Mucocele is pain-free and has a high possibility of recurrence [3]. They are sub-categorized into two types: mucous extravasation type and mucous retention type. The mucous extravasation type occurs due to trauma, e.g., lip biting, where retention of mucous occurs due to congestion of minor salivary glands [4,5]. Leakage into the soft tissues is caused by traumatized salivary ducts surrounding the gland, leading to extravasation of the mucocele. Surrounding the mucosa, there is the formation of a pseudocapsule in the final stage [6]. Clinically, both extravasation and retention cysts appear similar. It is mostly clinically diagnosed due to its pathognomonic appearance [7]. Retention mucocele can be found in any part of the oral cavity, whereas extravasation mucocele are most commonly seen on the lower lip, tongue, and buccal mucosa. The probabilities of mucocele being found in the posterior region of the tongue are low [8]. Mucocele usually do not show any symptoms but can sometimes cause difficulty in chewing, swallowing, or speaking. The lower labial mucosa is the most common location for the occurrence of mucoceles, as it contains adipose tissue, connective tissue, salivary glands, blood capillaries, and nerves. Any pathology that involves the above can cause mucoceles on the lips [9]. Mucocele on the oral mucosa could be present deep within the connective tissue or as a fluid-filled vesicle. There could be drainage of mucin from the superficial lesions, which precedes the recurrence. Fibrosis could be seen in long-standing lesions [10]. The diagnosis of mucocele could be confirmed based on the lesion’s colour, site, etiology, and consistency. A final diagnosis could be confirmed by histological investigations. Treatment modality for mucocele includes surgical excision, cryosurgery, laser excision, laser vaporization, marsupialization, and micro-marsupialization [8].

Case Report

Fig 1: Intraoral View Showing Mucocele on the Lower Lip.

A twenty-two-year-old male came to the outpatient department of oral medicine and radiology with the chief complaint of pain-free swelling in the lower right lip region for 2 months. The HOPI suggested that the swollen area was found labially in 32 and 33 regions. For the past 2 months, it was initially small in size and progressively increased to its present size. He also gave the history of an increase or decrease in size during mastication. The patient gave a history of lip-biting for 2 months. The patient had a history of difficulty with mastication and speech. The lesion was approximately 0.8× 0.7 cm in size. It is oval in shape, pink in colour, and well defined, and no surface changes have been noticed. On palpation, the inspectory findings, such as borders and the extent of the growth, are confirmed. The swelling is soft, fluctuant, and non-tender on palpation. The swelling was pale pink in colour. On intra-oral examination, the other findings of occlusal caries (36 and 46) were present. Generalized stains and calculus in the lower anterior region were present. On the basis of the clinical features and habit history of lip-biting, the case was diagnosed as mucocele. Restoration with 36 and 46 was done on the patient’s first clinical visit. The patient was systemically healthy. A complete hemogram revealed all blood cell counts within normal limits. As the patient reported discomfort during eating and while speaking, it was decided to go for an excisional biopsy performed under LA using an electrocautery following oral prophylaxis. An infiltration anesthesia of lignocaine containing 1:200,000 adrenaline was given in the area of interest. The electrocautery unit was set to cutting mode, and the growth was excised en masse using the loop electrode with normal saline for irrigation. Hemostasis was achieved. The specimen was then transferred to a vial containing 10% formalin and sent for histopathological assessment. Prior to discharge, post-operative instructions were given to the patient, with the advice to take analgesics should the need arise. The one-week recall revealed uneventful healing. No recurrence of the growth was observed during the two-month and six-month follow-up periods.

Fig 2: Intraoperative Photograph Showing Surgical Excision of the Mucocele.

Fig 3: Excised Tissue (Mucocele).

Fig 4: Uneventful Healing of the Surgical Area after Excision.

Histological Examination

Fig 5: Confirmed the Diagnosis by Histopathological Examination.

H and E-stained sections show sub-epithelial mucous-filled vesicles. A mild to moderate chronic inflammatory cell infiltration is observed in underlying connective tissue, along with excretory ducts and a few mixed acini suggestive of mucus extravasation cyst (Mucocele).

Etiopathogenesis

There are two etiological factors proposed, which are responsible for mucocele. One is trauma-related. (extravasation), and another cause is obstruction of the salivary gland ducts (retention). Extravasation mucoceles are caused by the extravasation of fluid into the surrounding tissue from the ducts or acini and elicit inflammatory changes. The obstruction type may be due to salivary calculi that cause retention of the saliva, hence dilation of the duct. Literature states that among the two types of 95% were extravasations, and it also undergoes three evolutionary phases.

Mucous spills diffusely from the excretory duct into conjunctive tissues, where some leucocytes and histiocytes are found.
Granulomas appear during the resorption phase due to histocytes, macrophages, and giant multinucleated cells associated with a foreign body reaction.
Connective cells form a pseudo-capsule without epithelium around the mucosa.

Discussion

Mucoceles, of minor salivary gland origin, is one of the most common mucosal lesions affecting the general population. Trauma and obstruction of the salivary gland duct are the two main etiological factors responsible for the lesion. There are two types of mucocele that have different etiological factors: painless, asymptomatic swellings that have a relatively rapid onset, enlarge, and then appear to involute because of the rupture of the contents into the oral cavity, resorption of the extravasated mucus, or retention of the mucin. The patient may relate a history of recent or remote trauma to the mouth or face, or the patient may have a habit of biting the lip. The duration of the lesion is usually 3-6 weeks; however, it may vary from a few days to several years in exceptional instances [11,12]. Often, an individual may rupture or unroof the vesicles by creating suction pressure. In such situations, the affected individuals report a chronic and recurrent history [11,13].

There are a few strong contributing factors that aid in the diagnosis of mucocele, such as appearance, clinical findings, and consistency. Literature suggests that lip biting is one of the common factors responsible for mucocele. The role of the radiograph has minimal contribution; ruling out any calcified structure such as sialolith would definitely contribute to the pathogenesis of the type of mucocele, especially for the retention type [14,15]. Histopathologically, the extravasated type is not lined by the epithelium (pseudo cyst), and in the case of the retention type (true cyst), it is lined by the epithelium. In our case report, based on the correlation of the clinical findings and the history of lip biting and based on the histopathology, the final diagnosis was in favour of the mucous extravasation phenomenon. Moreover, positive findings of a history of lip biting and histopathological absence of epithelial lining, along with the presence of spilled mucin and granulation tissue, led to the diagnosis of a mucocele of extravasation type.

Conventional surgical removal is the most common method used to treat this lesion. Other treatment options include CO2 laser ablation, cryosurgery, intralesional corticosteroid injection, micro marsupialization, and electrocautery [11-13]. The importance of this article is that clinically, the lesion is mistaken for benign salivary gland tumors and salivary gland duct cysts, which require a different treatment plan.

Conclusion

Mucocele are relatively common salivary gland cysts. Its recurrence rate is rare if the involved accessory salivary glands are removed. Care must be taken to eliminate the causative agent along with the surgical excision of the lesion.

Journal of Oral and Dental Health Research