|Year : 2013 | Volume
| Issue : 2 | Page : 94-96
Oral mucosal lipoma: An unusual presentation
Suryapratap Singh1, Akheel Mohammad2, Sharanjeet Singh Bedi3
1 Department of Neurological Surgery, Narayana Medical College and Hospital, Nellore, Andhra Pradesh, India
2 Department of Oral Surgery, Narayana Medical College and Hospital, Nellore, Andhra Pradesh, India
3 Department of Neurology, Narayana Medical College and Hospital, Nellore, Andhra Pradesh, India
|Date of Web Publication||22-Oct-2013|
Chinthareddypalam, Nellore - 524 002, Andhra Pradesh
Lipoma is a benign tumor of adipose tissue and one of the most common benign neoplasms of the body. One type of soft-tissue lesions of the oral cavity is lipoma. However, its occurrence in the oral cavity is very rare. It commonly occurs in the trunk and extremities. Lipoma accounts for only 1-4% of the intraoral soft tissue lesions. The intraoral site of occurence includes buccal mucosa, floor of the mouth and tongue. Here, we present a case of an intraoral lipoma in a 30-year-old young male patient. After 3 years follow-up, patients showed no signs of recurrence.
Keywords: Adipocytes, lipoma, oral, surgery
|How to cite this article:|
Singh S, Mohammad A, Bedi SS. Oral mucosal lipoma: An unusual presentation. SRM J Res Dent Sci 2013;4:94-6
| Introduction|| |
Lipomas are the most common soft-tissue mesenchymal neoplasms, with 15-20% of cases involving the head and neck region and only 1-4% affecting the oral cavity.  A lipoma in the mouth is an asymptomatic, slowly growing, rare benign tumor of mesenchymal origin consisting of fat.  It may present in various forms, such as sessile or pedunculated. It may be single and occurs as a lobulated tumor of variable sizes although mostly below 3 cm diameter and generally surrounded by a fibrous capsule.
The first description of an oral lesion was provided in 1848 by Roux in a review of alveolar masses, where he referred to as "yellow epulis." 
The etiology of lipoma is uncertain; some authors have suggested endocrine, traumatic and hereditary causes. 
The diagnosis is made by histopathological examination of an incisional or excisional biopsy specimen. An important feature is that the tumor tends to float when placed in a 10% formaldehyde solution.  Treatment consists of conservative surgical removal of the lipoma. Recurrences are rare.
The purpose of this paper is to report a case of patient with an oral lipoma whose treatment consisted of surgical excision. The paper includes a case report and a review of the literature.
| Case Report|| |
A 30-year-old male patient presented in Department of surgery with a round nodule in the right buccal mucosa region of the mouth. Patient informed that the tumor had grown to the present size within the last 6 months, which affected chewing and speech, but painless. An intraoral smooth well-defined sessile nodule of similar color to the surrounding mucosa was observed in the right buccal mucosa, a little above the alveolar ridge; it measured about 2.5 cm × 1.5 cm in size. Radiography revealed no bone involvement. An excisional biopsy was carried out. Microscopically, these tissues revealed sheets of mature fat cells containing clear cytoplasm and eccentric nucleus, with no evidence of cellular atypia or metaplasia, which confirmed that it was a lipoma. The tumor was placed in 10% formaldehyde, where it floated, suggesting fat content. Patient is currently being monitored and so far no recurrence has occurred.
| Discussion|| |
Lipomas of the mouth are benign tumors. They grow slowly, do not infiltrate other tissues, do not ulcerate and are painless. The cheek is the most common site of occurrence intra-orally followed by tongue, floor of the mouth, buccal sulcus and vestibule, palate, lip and gingiva. , This pattern corresponds closely to the quantity of fat deposit in the oral cavity. They are relatively rare in the mouth and the maxillofacial region. , According to the literature, mouth lipomas are distributed evenly between sexes; most of the patients being over 40 years of age. , The case is similar to other published reports as the patient was aged 57 years. In general, their prevalence does not differ with gender; although, a predilection for men has been reported. ,
The pathogenesis of lipoma is uncertain, but they appear to be more common in obese people. However, the metabolism of lipoma is completely independent of the normal body fat. If the caloric intake is reduced, lipoma does not decrease in size; although, normal body fat may be lost.
Lipomas are adipose mesenchymal neoplasms that rarely occur within the oral cavity (1-4%). Lipids unavailable for metabolism  coupled with the autonomous growth of a lipoma have rendered it to be a true benign neoplasm. 
Lipomas are slowly enlarging, with a soft, smooth-surface mass of the submucosal tissues. When it is superficial, there is a yellow surface discoloration. The lesion may be pedunculated or sessile and occasional cases show surface bosselation. 
Multiple lipomas of head and neck have been observed in neurofibromatosis, Gardner syndrome, encephalocraniocutaneous lipomatosis, multiple familial lipomatosis and proteus syndrome. Generalized lipomatosis have been reported to contribute to unilateral facial enlargement in hemifacial hypertrophy.  Although its etiology is unknown, possible causes may include trauma, infection, chronic irritation and hormone alterations. , In few cases of lipoma, rearrangement of 12q, 13q, 6p chromosomes have been observed. ,
Clinically, oral lipomas generally present as mobile, painless submucosal nodules, with a yellowish tinge as observed in our cases. In some cases, oral soft-tissue lipomas can present as a fluctuant nodule. Because of these clinical features, other lesions, such as oral dermoid and epidermoid cysts and oral lymphoepithelial cysts must be considered in the differential diagnosis of oral lipomas.  Furthermore, most oral lymphoepithelial cysts are found on the floor of the mouth, soft palate and mucosa of the pharyngeal tonsil,  which are uncommon sites for oral lipomas. Oral dermoid and epidermoid cysts also present as submucosal nodules and typically, occur on the midline of the floor of the mouth.  However, oral dermoid and epidermoid cysts can occur in other locations of the oral mucosa. Because an oral lipoma can occasionally present as a deep nodule with normal surface color, salivary gland tumors and benign mesenchymal neoplasms should also be included in the differential diagnosis.  Definitive diagnosis depends on the correlation between the histological and clinical features. 
The histopathology remains the gold standard in the diagnosis of lipoma. Lipomas are not very different in microscopic appearance from the surrounding fat. Like fat, they are composed of mature fat cells, but the cells vary slightly in size and shape and are somewhat larger, measuring up to 200 mm in diameter. Subcutaneous lipomas are usually thinly encapsulated and have distinct lobular patterns. Deep-seated lipomas have a more irregular configuration, largely depending on the site of origin. All are well-vascularized, but under normal conditions, the vascular network is compressed by the distended lipocytes and is not clearly discernible. Lipomas are occasionally altered by the admixture of other mesenchymal elements that comprise an intrinsic part of the tumor. The most common element is fibrous connective tissue, which is often hyalinized and may or may not be associated with the capsule or the fibrous septa. Lipomas with these features are often classified as fibrolipomas.  Quite often, however, lesional fat cells are seen to "infiltrate" into surrounding tissues, perhaps producing long thin extensions of fatty tissue radiating from the central tumor mass. When located within striated muscle, this infiltrating variant is called intramuscular lipoma (infiltrating lipoma), but extensive involvement of a wide area of fibrovascular or stromal tissues is best termed as lipomatosis. Occasional lesions exhibit excess numbers of small vascular channels (angiolipoma), a myxoid background stroma (myxoid lipoma, myxolipoma) or areas with uniform spindle shaped cells interspersed among normal adipocytes (spindle cell lipoma). When spindle cells appear somewhat dysplastic or mixed with pleomorphic giant cells with or without hyperchromatic enlarged nuclei, the term "pleomorphic lipoma" is applied. When the spindle cells are of smooth muscle origin, the term myolipoma may be used. It is angiomyolipoma when the smooth muscle appears to be derived from the walls of arterioles. Rarely, chondroid or osseous metaplasia may be seen in a lipoma, which is described as chondroid lipoma, osteolipoma or ossifying lipoma. On occasions, lipomas of the buccal mucosa cannot be distinguished from a herniated buccal fat pad, except by the lack of a history of sudden onset after trauma. Otherwise, lipomas of the oral and pharyngeal region are not difficult to differentiate from other lesions, although spindle cell and pleomorphic types of lipoma must be distinguished from liposarcoma.  Most of these microscopic variations do not affect the prognosis, which is usually good. 
The treatment of oral lipomas, including all the histological variants is simple surgical excision. Although the growth of oral lipomas is usually limited, they can reach great dimensions, interfering with speech and mastication and reinforcing the need for excision.  Surgical excision is the ideal treatment with rare recurrence as we did in our case.
| Conclusion|| |
Presented in this report is a case of intraoral lipoma in 30-year-old male. In referencing the literature to date, this type of case has been rarely documented.
Solitary lipomas has enthused little interest in the past and have largely been ignored in the literature. The reason is that the most lipomas grow insidiously and cause few problems other than those of a localized mass. Approximately, 15-20% of lipoma occurs in the head and neck region. Among the reported intraoral lipomas, 50% occur in the buccal mucosal region. Surgical excision is the ideal treatment with excellent outcome; however, complete resection should be emphasized as this is the key factor to avoid recurrence.
It is therefore important to diagnose the lesion correctly in the physical examination and histopathology to establish the prognosis. Health-care professionals need to understand this disease to treat it adequately.
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