SRM Journal of Research in Dental Sciences

: 2021  |  Volume : 12  |  Issue : 1  |  Page : 48--51

Mucocele showing both retention and extravasation phenomenon: An eccentric case report

Preethi Arunachalam1, Dineshkumar Thayalan2, Abdul Razak1, K Abiramivarman1, Abishek Gowtham1, Abinaya Rajesh1,  
1 Department of Oral Pathology, SRM Dental College, MDS, Ramapuram, Chennai, Tamil Nadu, India
2 Reader, Department of Oral and Maxillofacial Pathology, SRM Dental College, Ramapuram, Chennai, Tamil Nadu, India

Correspondence Address:
Dr. Dineshkumar Thayalan
MDS, Reader, Department of oral and maxillofacial pathology, SRM Dental college, Ramapuram, Chennai - 600 089, Tamil Nadu


An unusual report of mucocele presenting with both retention type and extravasation phenomenon has been presented. A 44-year-old male patient presented with a swelling in the commissure of the lip region for the past 2 months. A thorough clinical examination and history taking gave a diagnosis of a mucocele. This case highlights and discusses the histopathological features, differential diagnosis, and the theories behind the presentation of this rare case report.

How to cite this article:
Arunachalam P, Thayalan D, Razak A, Abiramivarman K, Gowtham A, Rajesh A. Mucocele showing both retention and extravasation phenomenon: An eccentric case report.SRM J Res Dent Sci 2021;12:48-51

How to cite this URL:
Arunachalam P, Thayalan D, Razak A, Abiramivarman K, Gowtham A, Rajesh A. Mucocele showing both retention and extravasation phenomenon: An eccentric case report. SRM J Res Dent Sci [serial online] 2021 [cited 2022 Oct 3 ];12:48-51
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Full Text


A mucocele is the most common lesion of the oral mucosa involving salivary gland and ducts, which is a consequence of a local trauma resulting in rupture of a salivary duct and spillage of the mucin into the adjacent soft tissues. Hence, mucoceles have been classified as (a) an extravasation mucocele or (b) a retention mucocele. The extravasation type is far more common than the retention type. This report presents an unusual case of a mucocele exhibiting both phenomena.

 Case Report

A 44-year-old male patient reported to the department of oral medicine with the chief complaint of swelling on the left commissure of the lip region for the past 2 months. History revealed a small swelling initially before 2 months, and the patient developed the habit of biting the swelling often, upon which the swelling increased and attained the current size.

On clinical examination, a well-defined round solitary swelling was seen on the left commissure of the lip extending to the left buccal mucosa for 1 cm along the occlusal plane in relation to 33, 34 tooth region which was measuring approximately 10 mm × 8 mm in dimension. The mucosa over the swelling was smooth and nonpulsatile. The swelling was reddish blue in color. On palpation, the inspectory findings regarding site, size, and shape were confirmed. The swelling was compressible, free movable, and was not fixed to any underlying structures. On palpation, no tenderness of the swelling and lymph nodes were elicited.

Excisional biopsy was done using laser cauterization method and was subjected for histopathological examination [Figure 1] and [Figure 2]. The specimens were roughly spherical in shape, soft in consistency and compressible in nature. The largest specimen measured approximately 1 cm × 1 cm in diameter and appeared bluish grey in color [Figure 3].{Figure 1}{Figure 2}{Figure 3}

The histopathological examination revealed parakeratinized stratified epithelium covering a mass of connective tissue consisting of loosely arranged collagen fibers. The epithelium was hyperplastic in few areas and ulcerated in few areas. The deeper portion of the connective tissue showed the presence of a cavity exhibiting eosinophilic-stained material resembling mucin and was surrounded by chronic inflammatory infiltrates along with few mucinophages and blood vessels and extravasated RBCs, suggestive of extravasation phenomenon [Figure 4], [Figure 5], [Figure 6]. There was also a presence of another cavity lined by an epithelium resembling ducal epithelium. The ductal epithelium appeared as single layer flat-to-cuboidal–shaped cells, and the cavity was filled with mucoid material suggestive of retention type of mucocele [Figure 7]. A section of normal mucous salivary gland was also evident.{Figure 4}{Figure 5}{Figure 6}{Figure 7}

Based on the thorough clinical examination and history taking along with the histopathological examination, the final diagnosis was given as mucocele showing both retention type and extravasation phenomenon.


Mucocele is a reactive lesion affecting the salivary gland, which is not lined by an epithelium, hence cannot be termed as a true cyst. Etiopathogenesis of the mucocele has been discussed by many authors. Local mechanical trauma is said to be the major reason. When the duct gets severed, mucus escapes into the surrounding tissue suggestive of extravasation phenomenon that attracts macrophages that attempt to phagocytose the foreign material.[1],[2] Other reason is obstruction of the salivary duct suggestive of retention type of mucocele. Some cases are also associated with improper feeding habit.[3] Mucoceles are reported with no specific gender predilection and seen in all age groups but predominant in the third decade of life as like our case. Congenital mucoceles are also seen in rare cases.[4] Lower labial mucosa is said to be the most common site encountered followed by the floor of the mouth, ventral part of the tongue, and buccal mucosa.[5] In our case report, the lesion was present in the commissure of the lip. Superficial mucoceles are usually seen in soft palate, retromolar region, and buccal mucosa. Rarely superficial mucocele are reported in labial mucosa which needs to be considered for differential diagnosis in case of neoplastic salivary gland lesions.[6] Mucoceles are dome-shaped, sessile nodules usually of few millimeters to centimeters and often resolved spontaneously, usually solitary; however, multiple mucoceles have also been reported. They are fluctuant but painless. They give a bluish tinge due to the Tyndal effect.

Histopathological features of retention type of mucocele include mucin filled dilated salivary duct with periductal hyalinization and interstitial lymphoplasmacytic infiltrates, and as a chronic state, it can result in interstitial fibrosis. In case of extravasation phenomenon, the pseudocyst is seen devoid of epithelial lining and the cavity appear to be filled with mucin, abundant epitheloid foamy histiocytes, neutrophils, and granulation tissue.[1] An unique presentation of both retention and extravasation phenomena was appreciated in the current case report, and thus far, no such case was reported in the literature as per our knowledge. Mucoceles are often confused with ranula, the latter is a variant of mucocele which presents as a swelling in the floor of the mouth and has a similar nature of mucocele formation, but the ranula involves the obstruction of a major salivary gland, predominantly the sublingual gland. Some authors have reported a salivary duct cyst under the classification of retention type.[7] Other differential diagnosis of the mucocele can be oral hemangiomas, oral lymphangiomas, pyogenic granuloma, lipomas, and soft tissue abscess. Long-standing mucocele lesion results in the appearance of fibroepithelial polyp due to fibrosis or can be termed as fibrosed mucocele.[8] Mucoepidermoid carcinoma (MEC) can also be listed in differential diagnosis, yet with the distinct types of atypical cell population, MEC can be ruled out. Minimal obstructive changes seen in retention type of mucocele could be confused with sialadentitis or with Sjogren's syndrome. A case of clear cell changes have also been reported in in mucocele by Piña et al., on the lower labial mucosa showing macrophage proliferation with abundant clear cytoplasmic vacuolation and signet ring formation.[9] Special stains used for mucocele are PAS, Mucicarmine, and Alcian blue. IHC marker CD68 usually shows positive to mucocele while CK5, CK6, CKAE1, and CKAE3 are said to be negative markers for mucocele.[10]

Management of mucocele is complete excision of the lesion along with the feeding salivary gland. Recurrence can be seen if there is an iatrogenic intraoperative damage to neighboring salivary gland or incomplete removal of the feeding gland in a large lesion. Complete histopathological examination to confirm salivary gland tumor. Laser ablation, super-potent topical corticosteroids, and gamma-linolenic acid have been reported to be effective in isolated case reports for superficial mucoceles. The prognosis is usually excellent when a complete resection is made.


Mucocele though is the most common lesion of the oral mucosa, the current case report is one of its kind featuring the presence of both obstructed and ruptured salivary duct in the same lesion. Although mucocele is a reactive lesion, clinicians have to take proper attention in arriving at correct diagnosis and management.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.


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