{'fraction_non_alphanumeric': 0.03076198697324021, 'fraction_numerical': 0.014439300007847445, 'mean_word_length': 4.938490214352283, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Co-existence of oral intra-muscular lipoma and lobular capillary hemangioma: A rare case report

Highlights • Intra muscular lipoma are rare with an incidence of 1.8%.• Most common site for oral intramuscular lipoma is tongue.• Intramuscular lipoma has shown recurrence due to difficulty in complete excision of the lesion.• Immunohistochemistry plays a crucial role to distinguish Lobular capillary hemangioma from pyogenic granuloma.• Co-existence of other lesions with Lipoma are reported in literature hence it is crucial to do a complete clinical examination in such cases.


Introduction
Lipoma is a benign mesenchymal soft tissue neoplasm of mature adipocytes. It accounts for 50% of all benign soft-tissue tumors [1]. 15%-20% of lipomas are found in head and neck region and only 1-4% cases are seen intraorally which accounts for 0.1%-5% of all the benign tumors of the mouth [2]. Intramuscular lipomas are rare, with an incidence of 1.8%. In literature lipomas are classified based on the location and histological pattern. According to location Lipoma's are either classified as subcutaneous lipoma i.e. (superficial to enclosing fascia in the subcutaneous tissue) and deep seated lipoma i.e. (deep to enclosing fascia).
Intramuscular lipomas are generally deep seated lipoma which originate inside the muscle [3]. Paget in 1853 was the 1st to describe a lipoma infiltrating the trapezius muscle. Later Greenberg et al. classified lipoma as intermuscular and intramuscular [4]. Intra-muscular lipoma can be histologically divided as infiltrating type, well circumscribed type and mixed type (i.e. with both infiltrating margins and well circumscribed areas) [3][4][5].
Hemangioma was 1st described by Poncet and Dor as Botryomycose humane in 1897 [6]. Hemangiomas are histologically classified as capillary, cavernous and mixed hemangiomas. It is relatively rare in oral cavity. Incidence of intraoral capillary hemangioma varies from 0.5% to 1.0% of all intraoral neoplasms [7,8]. Histologically capillary hemangioma are very similar to pyogenic granuloma but can be differentiated only on immunohistochemistry. Many studies classify pyogenic granuloma histologically in two types' lobular capillary hemangioma (LCH) and non-lobular capillary hemangioma (non-LCH). This is a rare case of Coexistence of Intramuscular lipoma with LCH who was treated in a tertiary care hospital under the department of Oral and maxillofacial surgery.  size and wasn't associated with pain, paresthesia, or difficulty in mastication. No such mass was observed on any other part of the body. There was no history of any tooth extraction or trauma to that region. Patient had a history of tobacco chewing since 10-15 years, 3-4 times a day. There was no relevant genetic information. No relevant medical history, surgical history, family history, drug history or psychosocial history.

Presentation of case
Extra-oral examination revealed a localized swelling on the left side of the face near commissure of the mouth measuring 5 cm × 3 cm, with smooth surface with no color change. On palpation it was soft in consistency, non fluctuant and non tender. No lymphadenopathy was noted (Fig. 1).
Intra-oral examination revealed a swelling on the lower left labial vestibule which was round in shape, yellowish in color and sessile, measuring 3 cm × 2 cm extending from the distal part of the canine till the mesial aspect of 1st molar, with smooth surface and distinct borders. On examination, an incidental finding of a mass on the ventral surface of the tongue was also noticed which was sessile, erythematous in nature measuring 1 cm × 0.5 cm with lobulated surface and irregular borders. On palpation, both the swellings were non-tender, soft in consistency with no blanching on pressure (Fig. 2).
An Orthopantomograph radiograph was done which showed no significant changes related to the area of interest. USG showed fairly well defined echogenic lesion in the intramuscular plane at the site of swelling measuring 2.2 × 0.8 cm in the region of left side of mandible. No evidence of calcification or vascularity were noted. Bony cortices and underlying muscle appeared normal. FNAC was done twice but yielded no material.
A provisional diagnosis of lipoma was made based on its clinical signs and symptoms. The patient was then advised an excisional biopsy under general anesthesia. Patient was kept NBM for 7 h before the surgery. The work has been reported in line with SCARE 2018 criteria [9]. Surgery was performed by the 1st author of this case report.

Surgical management & follow up
Patient was intubated via nasotracheal route, scrubbed and draped in aseptic manner. 2% lignocaine with 1:80,000 adrenaline was injected around the swelling. An Intraoral longitudinal incision of 4 cm was made over the mucosa covering the swelling in lower left vestibule, blunt dissection was done throughout and  complete lesion was excised. Tongue mass was excised, hemostasis was achieved and closure of mucosa was done using 3-0 Vicryl synthetic absorbable sutures on both the sites. Excised tissue was then stored in 10% formalin and was sent for histopathological examination (Fig. 3). Post-operative pressure dressing was given in the chin region for 3 days. Post-op antibiotic and analgesic were administered i.e. Inj Augmentin 1.2 gm Intravenous BD, Inj Dynapar (in 100cc ns) Intravenous TDS. After a follow-up of 1 year patient showed no signs of recurrence. Clinically the swelling on left chin region subsided after post op day 3. No signs of mental nerve paresthesia.

Histopathological examination
Two samples labelled as (A) mass of lower labial vestibule measuring 2 cm × 1.5 cm × 1 cm (Fig. 4) and (B) proliferating lesion at the tip of the tongue measuring 1 cm × 0.5 cm × 0.5 cm were sent for histopathological investigation. Sample A showed features of lipoma that is thin connective tissue septa separating lobules of mature adipocytes while sample B showed a benign tumor composed of blood vessels comprising of small capillary sized vascular channels. There was no evidence of any atypia or malignancy. Immunohistochemistry showed positive reaction for CD31 marker on endothelial cell of blood vessels (Fig. 5).

Discussion
Lipoma is a benign soft tissue tumor of mesenchymal origin, most commonly affecting the trunk and proximal part of extremities. Gender predilection also differ depending on type of intra-oral lipoma. Microscopically they are categorized as classic lipoma, fibro-lipoma, angiolipoma, spindle cell lipoma, pleomorphic, myxoid, sialolipoma, and intramuscular lipomas. A higher female predilection of fibro-lipoma was reported in a study by Juliasse et al. (2010) and osterne et al. (2019) [10]. All cases of sialolipoma which were observed in a study by juliasse et al. were female. Intramuscular or infiltrating lipoma is a rare type of lipoma, originating between skeletal muscle bundles and infiltrating through the intramuscular septa. Common site of origin in head and neck region include orbicularis muscle, temporalis muscle. Most common intraoral site was tongue [11,12]. Flecther et al. in his study found 27% of all the infiltrative lipoma in head and neck region whereas 12.5% of all well circumscribed type located in head region [13]. Clinically Intramuscular lipomas are generally slow growing well defined, round to ovoid in shape, sessile, yellow in color due to its thin overlying mucosa [14].
The etiology and pathogenesis of intra-oral lipoma remains unclear, but few theories are put forth which includes "Hypertrophy theory," which states that obesity and inadvertent growth of adipose tissue may contribute to the formation of these oral lesions, Metaplasia theory suggests formation of lipoma because of aberrant differentiation of in situ mesenchymal cells into lipoblast since fatty tissue can be derived from mutable connective tissue cells almost anywhere in the body.
CT, MRI and USG can be used to understand the location, extent and nature of swelling. Fine needle aspiration cytology (FNAC) can also be performed in order to confirm the diagnosis, however histopathological diagnosis is the gold standard method for the diagnosis of lipoma. Surgical excision is the treatment of lipoma. After excising it completely, chances of recurrence and malignant transformation are rare in lipomas. Studies suggest recurrence is commonly seen in Intramuscular lipoma (infiltrating lipomas) due to its difficulty in complete excision. Other non-surgical management include lipolysis by injecting agent's phosphatidyl choline/ sodium deoxycholate (PDC/DC) compounds in the subcutaneous fat [15]. Co-existence of Intraoral Lipoma and Lobular capillary hemangioma is extremely rare and only one case of coexistence of lipoma with multiple pyogenic granuloma was reported by Alphy Alphonsa Sebastian et al. in 2017 in a 52 year old female patient [16].
The incidence of intraoral capillary hemangiomas are extremely rare and it varies from 0.5%-1.0% of all intraoral neoplasms especially with female predilection (ratio of 3:1) in second and third decades of life [17,18].
Pyogenic granuloma is often confused with lobular capillary hemangioma. There are two histological types of pyogenic granuloma of the oral cavity: the LCH and non-LCH type. Differential diagnosis for this lesion are Traumatic fibroma, pyogenic granuloma, Epulis granulomatosa etc.
In an analysis of 244 cases of gingival lesions in South Indian population, Shamim et al. found that non-neoplastic lesions accounted for 75.5% of cases with lobulated capillary hemangioma being most frequent lesion, accounting for 52.71% cases [19].
CT Contrast, MRI, USG and Color Doppler can be done in order to confirm the diagnosis. In this case histopathological examination of the excised lesion followed by immunohistochemistry was performed in order to confirm the diagnosis.
Immunohistochemistry play a crucial role in distinguishing pure capillary hemangioma from pyogenic granuloma [20].
In pyogenic granuloma the immunohistochemistry shows absence of CD31, CD34, CD105 and Tie2 of perivascular ovoid mesenchyma. The perivascular mesenchymal spindle cells revealed immunopositivity to SMA [20]. Both pyogenic granuloma and Capillary hemangioma shows presence of CD31 CD34 CD105 on endothelial cell. Immunohistochemical analysis was done in our case which reveal endothelial cells and ovoid cells are positive to CD34 marker [20].
The treatment of LCH is mainly surgical excision. Surgical excision should be done with utmost care because of high risk of increased intra and postoperative bleeding which should be managed properly if excision is planned. However in this case due to its small size excisional biopsy was planned and bleeding was controlled with absorbable sutures.
Patient's main pre-operative concern was the swelling and poor esthetics caused by it. However after excision the swelling was completely eliminated restoring the facial symmetry. Patient was satisfied as there were no extra oral scars since the whole procedure was done via intra-oral approach.
Hence complete examination of oral cavity plays a crucial role to rule out co-existence. Complete excision of intramuscular lipoma and clear histological diagnosis of LCH is important to reduce the chances of recurrence.

Declaration of Competing Interest
The authors report no declarations of interest.

Funding
No source of funding.

Ethical approval
Not applicable.

Consent
Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the editor-in-chief of this journal on request.

Author contribution
1. Dr. Yogesh Kini: The conception and design of the study, analysis and interpretation of data, drafting the article, final approval of the version to be submitted. 2. Dr. Anish Kamat: The conception and design of the study, analysis and interpretation of data, drafting the article, final approval of the version to be submitted. 3. Dr. Komal Navalkha: The conception and design of the study, analysis and interpretation of data, drafting the article, final approval of the version to be submitted. 4. Dr. Swapna Nayan: Analysis and interpretation of data, drafting the article, final approval of the version to be submitted. 5. Dr. Geetanjali Mandlik: Analysis and interpretation of data, drafting the article, final approval of the version to be submitted. 6. Dr. Damini Gupta: Analysis and interpretation of data, drafting the article, final approval of the version to be submitted.

Registration of research studies
Not applicable.

Provenance and peer review
Provenance and peer review not commissioned, externally peerreviewed.