|Year : 2015 | Volume
| Issue : 4 | Page : 588-592
Fibrolipoma: A rare entity - Case series
Kavita A Amale1, Narendra T Chaudhari2, Sweety S Bafna2, Hemant R Umarji1
1 Department of Oral Medicine, Diagnosis and Radiology, Government Dental College and Hospital, Mumbai, Maharashtra, India
2 Department of Oral Pathology and Microbiology, Government Dental College and Hospital, Mumbai, Maharashtra, India
|Date of Submission||19-Aug-2015|
|Date of Acceptance||24-May-2016|
|Date of Web Publication||19-Aug-2016|
Dr. Narendra T Chaudhari
Nirman Park Phase 3, A-6, Room No: 4, Santoshi Mata Road, Kalyan West - 421 301, Mumbai, Maharashtra
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Lipomas are benign soft tissue neoplasms of mature adipose tissue usually seen in the head and neck region. Intraoral lipomas are rare lesions, which may be discovered during routine dental examinations since they present as a slow-growing, painless, and asymptomatic yellowish mass. Fibrolipoma is one of the rare variants of the lipoma, and very few cases have been reported in the oral cavity. These lesions infrequently cause pain, but may grow to large size causing difficulty in speech and mastication. Surgical excision is the treatment of choice, and the prognosis is generally good as recurrence rate is very less. Here, we present two cases of fibrolipoma and a brief review of literature.
Keywords: Excision, fibrolipoma, neoplasm, recurrence
|How to cite this article:|
Amale KA, Chaudhari NT, Bafna SS, Umarji HR. Fibrolipoma: A rare entity - Case series. J Indian Acad Oral Med Radiol 2015;27:588-92
|How to cite this URL:|
Amale KA, Chaudhari NT, Bafna SS, Umarji HR. Fibrolipoma: A rare entity - Case series. J Indian Acad Oral Med Radiol [serial online] 2015 [cited 2022 Nov 26];27:588-92. Available from: http://www.jiaomr.in/text.asp?2015/27/4/588/188769
| Introduction|| |
Lipomas are benign mesenchymal neoplasms consisting of mature adipocytes, generally enclosed by a thin fibrous capsule.  Intraoral lipoma was first described by Roux in 1848, to which he referred to as "yellow epulis."  Classic lipomas are the most common, followed by fibrolipomas among the intraoral lipomas.  Lipomas can be attributed to mechanical, endocrine, and inflammatory influences, which may lead to the differentiation of multipotent mesenchymal cells in fat tissue, cartilage, and bone. Systemic and local influences such as local trauma or prolonged ischemia may cause modification of mesenchymal cells. The pathogenesis of fibrolipoma remains unclear. It may be congenital due to an endocrinal imbalance, product of a degenerated fibromatous tumor, or arise from the maturation of lipoblastomatosis. 
About 15-20% of lipomas occur in the head and neck region, but only 1-4% occurs in the oral cavity. They are seen in patients belonging to fourth or fifth decade with equal gender predisposition, although a male predilection is also seen.  Lipomas are commonly located on buccal mucosa (53.7%), buccal sulcus (14.6%), and tongue (9.8%). They are encapsulated, but may present an infiltrating growth if capsule is absent. These are slow-growing, painless, and asymptomatic lesions, which may interfere with speech and mastication.  Few lesions become ulcerated which leads to difficulty in diagnosis.  Intra-osseous lipomas may arise from the soft tissue adjacent to the bone or may occur in an intramedullary location. 
The histological variants seen are classic lipoma (41.5%), fibrolipoma (34.1%), spindle cell lipoma (9.8%), sialolipoma (9.8%), osteolipoma (2.4%), and chondrolipoma (2.4%).  Histologically, the tumor is composed of adult fat cells that are sub-divided into lobules by fibrous connective tissue septa. The histological pattern may show varied features such as dense fibrous connective tissue septa, spindle cell components, mitotically active atypical cells, mature blood vessels, myxoid stroma, or even salivary acinar structures are seen along with mature adipose tissue depending on each variant. 
Intraoral lipomas are managed by conservative local excision without any recurrence, but intramuscular lipomas due to their infiltrating nature and when multiple,  show recurrence rate of as high as 62.5%.  Oral fibrolipomas are uncommon in the oral cavity with few cases documented so far. As the proliferative activity of fibrolipoma is greater than the other variants, the need for accurate diagnosis is important.  Hence, we present here two cases and a brief review on fibrolipomas.
| Case Reports|| |
Case report 1
A 19-year-old female patient reported with a complaint of gradually increasing intraoral swelling on the right cheek. The patient was apparently alright when she noticed a growth of about 0.5 cm in diameter 6 years ago and since it was asymptomatic; she did not report to the dentist. However, the growth gradually increased to its present size and caused difficulty in mastication which prompted the patient to visit the hospital. There was no history of bleeding and discharge from the swelling, and no treatment was taken for the lesion. Extraoral examination showed no facial asymmetry. There was no associated lymphadenopathy.
Intraoral examination showed pink-colored, exophytic, pedunculated growth of 4 cm × 3 cm in size on the right buccal mucosa opposing crowns of 15 and 16. The growth was well-circumscribed, with keratotic bite markings on the surface. The surface was smooth and glossy with intact mucosa. On palpation, it was soft in consistency, nontender with no bruit, and slightly mobile. Slip sign was not demonstrated. The swelling was fluctuant with no bleeding [Figure 1]. Provisional diagnosis of lipoma and differential diagnosis of fibroma and neurofibroma were considered. The lesion was completely excised and subjected to histopathological examination. Microscopic examination revealed thin atrophic surface epithelium and dense connective tissue. The stroma consisted of adipose tissue interspersed between numerous collagen fiber bundles [Figure 2] and [Figure 3]. Based on the above features, a final diagnosis of fibrolipoma was given. Postoperative follow-up of the patient after 6 months showed no signs of recurrence [Figure 4].
|Figure 1: Extraoral view: No facial asymmetry; Intraoral view: Pink-colored, exophytic, pedunculated growth on the right buccal mucosa (Case 1)|
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|Figure 2: Thin, atrophic epithelium and dense collagen fibers along with adipose tissue (Case 1) (H and E, ×4)|
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|Figure 3: Mature adipocytes surrounded by numerous collagen fibers (Case 1) (H and E, ×10)|
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Case report 2
A 41-year-old male patient visited our outpatient department with a complaint of swelling in the left back region of jaw since 3 years. The patient did not feel any discomfort as the swelling initially was small about 0.2 cm in size, but as it increased slowly over the years, it affected patient's chewing ability. There was no bleeding and discharge from the swelling, and no significant medical or family history. The patient had no deleterious habit history. There was no facial asymmetry and associated lymphadenopathy on external examination.
A well-defined, round, pedunculated, pinkish-white growth on the left pterygomandibular raphe distal to 38, measuring about 2 cm × 2 cm in size was seen. Surface of the growth appeared smooth and shiny. Overlying mucosa was intact with superficial blood vessels seen. It was soft-to-firm in consistency, pedunculated, no bruit, slightly mobile, and nontender on palpation. Slip sign was negative, and bleeding was not seen. The lesion prevented the teeth from complete occlusion [Figure 5]. Provisional diagnosis of fibroma and differential diagnosis of lipoma and neurofibroma were given. The lesion was completely removed and sent for histopathological examination. Microscopic examination showed surface epithelium and dense, mature connective tissue. The stroma predominantly consisted of collagen fiber bundles. Deeper areas of stroma showed mature adipocytes surrounded by collagen fiber bundles consistent with fibrolipoma [Figure 6] and [Figure 7]. Postoperative follow-up of the patient after 4 months showed no signs of recurrence [Figure 8].
|Figure 5: Extraoral view: No facial asymmetry; Intraoral view: Round, pedunculated, pinkish-white growth on the left pterygomandibular raphe (Case 2)|
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|Figure 6: Thin, atrophic epithelium and dense collagen fibers showing adipose tissue in deeper areas (Case 2) (H and E, ×4)|
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|Figure 7: Mature collagen fibers with few interspersed matured adipocytes (Case 2) (H and E × 10)|
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| Discussion|| |
The metabolism of fat cells in a lipoma is different from normal fat cells, as during starvation, there will be a loss of fat from normal fat deposits in the body, but not from a lipoma. Furthermore, fatty acid precursors are incorporated rapidly into lipoma fat than into normal fat. Basically, the lipid present in lipoma is not available for metabolism.  Fibrolipoma according to the WHO classification is a rare microscopic variant of lipoma, which is characterized by mature adipose tissue interspersed by dense fibrous connective tissue. ,
The various factors attributed for the etiology of fibrolipoma are congenital, endocrine imbalances, degeneration of fibromatous tumor, or from the maturation of lipoblastomatosis.  The growth rate of fibrolipomas is faster than the classic variants. Even though fibrolipomas are benign tumors, few cases of conversion to liposarcoma are also reported.  The consistency is soft-to-firm, which depends on the quantity and distribution of fibrous tissue and the depth of the tumor. It is most commonly seen in the buccal mucosa and buccal vestibule,  and it also shows a slight predominance in females. 
Fibrolipoma is the most frequent microscopic variant of oral lipomas. Microscopically, the fibrolipoma is composed of lobules of "chicken-wire" appearing, benign adipocytes with a component comprising broad bands of dense collagen. It is mostly well circumscribed and maybe thinly encapsulated like the classic lipoma.  Differential diagnosis includes many benign mesenchymal tumors such as fibromas, simple lipomas, and minor salivary gland tumors either benign or malignant.  Magnetic resonance imaging is a very helpful tool for the diagnosis of all kind of lipomas.  The treatment for fibrolipoma is surgical excision which is associated with rare recurrence. Malignant transformations in the oral and maxillofacial regions are rare. 
The pathological conditions such as neurofibromatosis, Gardner syndrome, encephalo-craniocutaneous lipomatosis, multiple familial lipomatosis and Proteus syndrome, Cowden's syndrome, multiple hamartoma syndrome, and Dercum's disease are associated with multiple head and neck lipomas.  As the clinical course of fibrolipoma is usually asymptomatic, the lesion grows to a large size, leading to cosmetic problems that prompt the patient to take treatment. A few complications such as obstruction of upper airway leading to asphyxial death in case of esophageal fibrolipoma and liposarcoma in long-standing cases can also occur. , The Ki-67 and proliferating cell nuclear antigen expression are increased in fibrolipomas than in other variants, which suggest a greater proliferative rate and faster growing pattern, but this feature does not affect the prognosis of the lesion.  The cases we presented were of young female and a middle-aged male showing soft-to-firm growth suggestive of lipoma. The lesions were confirmed as fibrolipoma on histopathological examination.
| Conclusion|| |
Fibrolipoma may resemble many lesions clinically and pose a diagnostic challenge to general dentists. Histopathological examination is advised for the confirmation of diagnosis. This would be helpful in providing treatment and prevention of complications such as malignant transformation. Fibrolipoma is a rare lesion, so more cases should be documented to make dental professionals aware of its features.
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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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8]