Chondroid Lipoma: A Rare Variant of Lipoma
Correspondence Address :
Samadrita Paul,
C/o Gitesh Das, F-107, Shiva Shree Gardens Apartments, Block 2, 4th Cross Road, Remco BHEL Layout, Rajarajeshwari Nagar, Bengaluru-560098, Karnataka, India.
E-mail: samadritapaul05@gmail.com
Lipoma is a benign, growing tumour of mesenchymal origin composed of mature fat cells and adipocytes. They can occur in the subcutaneous layer or at intramuscular or intermuscular sites. Oral lipoma, a benign tumour of mesenchymal origin composed of mature adipocytes and usually surrounded by a thin fibrous connective tissue capsule, is rare and mostly found on the buccal mucosa and tongue. Hereby, the authors present a case of Chondroid Lipoma (CL), a very rare subtype of lipoma involving the ventral surface of the tongue in a 50-year-old female patient. The Chondroid Lipoma, a variant of lipoma, is extremely rare in the oral and maxillofacial region containing both embryonal fat and cartilage.
Adipocytes, Chondroid matrix, Fibrous tissue, Mesenchymal tissue
A 50-year-old female patient visited the Department of Oral Medicine and Radiology with a chief complaint of swelling under her tongue for 20 days. The patient first noticed the growth 20 days ago; before that, she did not notice any growth below her tongue. There was no history of pus discharge, bleeding, or trauma associated with the growth. The growth is not associated with pain or any kind of discomfort. The patient’s past medical, dental, and family histories were non-contributary. On general physical examination, the patient was moderately built and nourished with pallor present. Intraoral examination revealed a well-defined sessile growth measuring about 1.5×1.5 cm present on the ventral surface of the tongue which was in close approximation with the root stumps irt 32, 31, 41, 42 [According to FDI system] (Table/Fig 1),(Table/Fig 2). On palpation, the growth was soft in consistency, mobile, and non tender with a negative diascopy test. On hard tissue examination, root stumps were present irt 31, 32, 41, 42, 43, 44, 46, 48. Based on the clinical findings, a provisional diagnosis of mucocele involving the ventral surface of the tongue was made. Traumatic fibroma and lipoma were considered under the differential diagnosis. Routine blood examination results were found to be within normal limits. The lesion was excised under local anaesthesia. Microscopic examination revealed focal areas of mature cartilage with surrounding lobules of adipocytes suggestive of CL (Table/Fig 3),(Table/Fig 4). Based on these, authors confirmed the diagnosis of CL. The patient was followed-up for four months, and no recurrence was noted.
Lipoma, being the most common benign tumour of the body, earns the title of the “universal tumour” or “ubiquitous tumour” (1). It occurs in all parts of the body where there is the presence of adipose tissue (2). Oral lipoma is a relatively rare entity, comprising 2.2% of all lipomas and 1%-4% of all benign tumours of the oral cavity (3). Oral lipomas can be sessile or pedunculated with soft, smooth-surfaced nodular masses, which are asymptomatic and mostly an incidental finding, but large lipomas can cause functional difficulties (2). The findings of a few case reports published in the literature has been depicted in Table/Fig-5 (4),(5),(6),(7),(8),(9). Oral lipoma was first demarcated by Roux in 1848 and referred to as the “yellow epulis” (10). It usually occurs in adult patients within an age range of 40-60 years without any gender predilection, and sites include the tongue, floor of the mouth, buccal mucosa, gingiva, mucobuccal or labial folds, palate, and major salivary glands (10). Morphologically, oral lipoma can be classified as diffuse, superficial, and encapsulated forms (10). Oral lipoma is usually asymptomatic with a thin epithelium giving a yellow discolouration, but if it is in deeper tissues, it may appear pink. It is soft in consistency when palpated, and usually, the size does not exceed 3 cm at the time of diagnosis, but it can increase upto 5-6 cm over a period of years (11).
According to Takizawa A et al., (5) lipomas can be classified as:
• Classic lipoma; lipoma variants, such as:
1) Angiolipoma;
2) Chondroid Lipoma (CL);
3) Myolipoma; and
4) Spindle cell/pleomorphic lipoma.
• Hamartomatous lesions;
• Diffuse lipomatous proliferations; and
• Hibernoma.
According to the World Health Organisation (WHO) 2002, CL is defined as “a unique and recently recognised benign adipose tissue tumour containing lipoblasts, mature fat cells, and chondroid matrix” (11). CL, a variant of lipoma, is extremely rare in the oral and maxillofacial region containing both embryonal fat and cartilage. It was first described by Meis and Enzinger in 1993, who reported 20 cases, out of which only two were located in the head and neck region (12). It usually presents in the third or fourth decade of life, occurring rarely in children less than 10 years old. It presents as a slow-growing, painless mass, most commonly in limb girdles and proximal extremities, and rarely in the head and neck region (particularly intraorally). It behaves benignly and has no reported cases of recurrence and metastasis, but sometimes it might show rapid growth, which can be misinterpreted as malignant transportation (12).
There are two hypotheses regarding the origin of the cartilaginous component of this tumour:
• Due to mechanical stress, it leads to a metaplastic change in an ordinary lipoma; and
• Under the influence of growth factor in this lesion, it might arise from the multipotential stem cells (11).
According to Shafer’s, lipoma can be histologically classified as classic lipomas and its variants, namely fibrolipoma, intramuscular lipoma, spindle cell or pleomorphic lipoma, myxoid lipoma, angiolipoma, salivary gland lipoma or sialo lipoma, CL, myolipoma, osteolipoma, and atypical lipoma. Amongst these histological variants, classic lipoma and fibrolipoma are the most common, representing about 80% of all reported cases. Rarely, lipoma may be composed of chondroid metaplasia called CL (10).
The CL histologically contains nests, sheets of cytoplasmic vacuolation or eosinophilic granular cytoplasm, and cords of rounded cells within prominent myxoid to hyalinised chondroid stroma with mature fat present in variable amounts (12). In present case, the section when stained with Haematoxylin and Eosin (H&E) showed stratified squamous epithelium surrounding lobules of adipocytes along with focal areas of mature cartilage suggestive of CL.
On the other hand, chondrolipoma, which also commonly occurs in the head and neck, is a whole different entity that can be misinterpreted as CL (6). It contains mature cartilaginous areas, and the adipose component is entirely composed of mature tissue with a lack of any lipoblastic cells, whereas CL is composed of mature adipocytes admixed with multivacuolated lipoblast-like cells in a myxohyaline and chondroid matrix, giving a pseudosarcomatous appearance (9),(13). CL has previously been misdiagnosed as sarcomas, either chondrosarcoma or liposarcoma, particularly extraskeletal myxoid chondrosarcoma (11). Extraskeletal chondrosarcoma can be excluded because it does not contain adipocytes or lipoblast-like cells as seen in CL (9).
In present case, surgical excision was performed without any recurrence in the periodic follow-up. Diagnostic aids such as ultrasonography, computed tomography, and magnetic resonance imaging may be performed to determine the location, extent, and margins of the mass in case of infiltrating lipoma, but otherwise conservative treatment is the desired protocol without causing much discomfort.
The CL is an extremely rare variant of oral lipoma. The characteristics of this oral lesion tend to show few deviations from the classical oral lipoma, chiefly being the marked predilection for involvement of the ventral aspect of the tongue. Being the rarest, the present case report will help in considering it as a marked differential diagnosis in the future.
DOI: 10.7860/JCDR/2024/69185.19257
Date of Submission: Dec 19, 2023
Date of Peer Review: Feb 09, 2024
Date of Acceptance: Feb 24, 2024
Date of Publishing: Apr 01, 2024
AUTHOR DECLARATION:
• Financial or Other Competing Interests: None
• Was informed consent obtained from the subjects involved in the study? Yes
• For any images presented appropriate consent has been obtained from the subjects. Yes
PLAGIARISM CHECKING METHODS:
• Plagiarism X-checker: Dec 20, 2023
• Manual Googling: Feb 13, 2024
• iThenticate Software: Feb 22, 2024 (11%)
ETYMOLOGY: Author Origin
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