Rare case of intra-oral palatal (soft palate) fibro-lipoma

INTRODUCTION

The palate forms a division between nasal and oral cavity. It is divided into two parts - hard palate and soft palate. A mass or growth in the palate can be a resultant of numerous pathologies which includes periapical lesion, periodontal diseases, reactive process, salivary gland pathologies or neoplastic process. They may be either congenital or acquired. Masses of congenital origin are usually associated with unerupted tooth and torus palatinus while acquired conditions are resultant of dental abscess, salivary gland neoplasm, fibro-osseous lesion, fibrous or fatty lump, neurogenic tumors, epithelial or connective tissue neoplasm such as papilloma, squamous cell carcinoma, browns tumor.

They are best examined by inspection and palpation. Endoscopic examination and radiological examination can help to rule out pathologies but confirmatory diagnosis can be reached only with help of histopathology. Lipoma is a benign mesenchymal neoplasm usually surrounded by a thin fibrous capsule around mature adipocytes.¹ They contribute as the most common soft tissue tumor in the human body and amongst them, about 20% cases occur in the head and neck region.¹ Oral lipomas are however very rare and comprise only 0.5-4% of allbenign tumors of the oral cavity.^1,2 Usual presentation is as painless, well-circumscribed, slow-growing submucosal or superficial masses. The most common occurring site being buccal mucosa, often followed by tongue, floor of mouth, lips, and gingiva.^1,2 Here, we report a case of 30 years male patient with mass on soft palate and discuss its clinical relevance.

CASE REPORT

A case of 30-years-old male patient presented with chief complaints of post nasal drip, nasal obstruction (right side>left side) and intermittent headache for 3 years. There was also history of snoring and mouth breathing during sleep. There weren’t any complaints pertaining to speech or deglutition.

On diagnostic nasal endoscopy there was slight deviated nasal septum towards left side anteriorly and a smooth surfaced, firm, non-pulsatile mass was found situated over upper surface of soft palate in immediate posterior close relationship with the posterior-most part of the nasal septum leading to a suspended mass hanging in the nasopharynx with support of a small stalk (Figure 1).

Patient was advised Computed tomography paranasal sinus (CT-PNS) which showed presence of fairly large lobulated (3×2×2 cm) predominantly fat density lesion situated over the soft palate that was projecting into the nasopharynx causing significant nasopharyngeal obstruction (Figure 2).

Patient underwent combined approach (trans-oral + endoscopic) excision of the mass under general anaesthesia with coblation of the stalk behind the nasal septum. Under general anaesthesia, an enmass excision of the suspending mass in the nasopharynx was performed under endoscopic supervision with help of coblation, followed by final detachment of the inferior aspect of the mass (stalk) trans-orally in the rose’s tonsillectomy position with parallel endoscopic guidance from nasal route. The mass was in toto delivered trans-orally and the point of attachment of the stalk was then endoscopically coblated ensuring no remnant.

Mass was then sent for histopathological examination. Patient’s surgery and post-surgical stay of 2 days were uneventful with no residual masticatory or speech disturbances. He was started on oral feeds on the 3rd postoperative day and remained comfortable as well as asymptomatic even on follow up.

Histopathological examination of the mass suggested presence of abundant adipose tissue, with trace presence of fibro-collagenous tissue and chronic inflammatory cells, with no evidence of any malignancy (Figure 3).

DISCUSSION

Lipoma is a benign slow-growing neoplasm composed of maturefat cells. The first description of oral lipomas was given by Roux in 1848 in a review of alveolar mass; he referred it as a ‘yellow epulis’.³ Lipomas are rare in the oral cavity. The most common location of lipoma in the oral cavity is the buccal mucosa, a region abundant in fatty tissue, followed by tongue, lips, and floor of the mouth.^1,2 This pattern of location of the tumor corresponds to the quantity of fat deposits in the oral cavity. The palate has very little fatty tissue and the incidence of a lesion here is quite low.⁴ Although lipoma may resemble fat cells histologically, they differ from them metabolically. It has been shown that the fat of lipoma is not used for energy production during the starvation period, as it happens with normal adipose tissue.^1,2

No clear explanation exists regarding the pathogenesis of oral lipomas.⁴ Various mechanisms have been proposed explaining the origin of these tumors in the oral cavity which range from origin from lipoblastic embryonic cell nests, metaplasia of muscle cells, and trauma to chronic irritation and fatty degeneration.^5,6

Although most lipomas are asymptomatic, but if symptomatic, the symptoms depend upon the rate of growth, size, and location of the tumor. Commonest presentation is of a painless palpable mass where examination reveals a well-defined, soft to firm, and smooth-surfaced tumor. The tumor is soft and flat when the underlying muscle is relaxed and becomes firm and more spherical when the muscle contracts.

The differential diagnosis includes lesions with similar clinical features, such as thyroglossal duct cysts, pleomorphic adenoma, mucoepidermoid carcinoma, lymphoepithelial, or dermoidoral cysts.¹

There are various subtypes of intra-oral lipomas namely simple lipoma, fibro lipomas, angio lipomas, intramuscular or infiltrating lipomas, pleomorphic lipomas, spindle-cell lipomas, salivary gland lipomas (sialolipomas), and myxoid lipomas.^1,2,4,5 Amongst these, simple lipoma is the most common form seen.

The diagnosis is based on the cytological examination of the tissue. Fine needle aspiration cytology (FNAC) is always a good option, but histopathological examination of tissue is definitive and hence confirmatory. Radiological evaluation with CT scan is seldom necessary which helps in knowing the nature as well as the extent of the mass including infiltration into underlying structures.

Treatment is indicated in symptomatic patients especially if disturbs daily pursuits which may or may not include interference with speech, mastication, or if cosmetically unacceptable.^4-6

The treatment of oral lipomas regardless of the histologic variance is surgical excision.^4-6 The prognosis is good as recurrences are uncommon, but they may occur in the infiltrative variant.

CONCLUSION

To conclude, lipomas are uncommon tumors in the oral cavity and palate being the rarest amongst them as is our case. It would be strongly advocated to keep lipoma in the differential diagnosis when evaluating a palatal mass. Also, it is worth mentioning and recommending that a careful radiological examination of large lesions arising from the palate is a must before approaching for surgery.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: Not required

REFERENCES

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