Immunoexpression of calcitonin and glucocorticoid receptors in central giant cell lesions of the jaws.

BACKGROUND: This study analyzed the immunoexpression of calcitonin receptor (CTR) and glucocorticoid receptor (GR) in central giant cell lesions (CGCLs) and verified potential associations with patient's response to clinical treatment with intralesional injection of triamcinolone. MATERIALS AND METHODS: Fifty-four cases of CGCLs, including 22 non-aggressive, and 32 aggressive, were investigated by immunohistochemistry. RESULTS: Surgery was the therapeutic choice for 53.1% of the aggressive CGCLs, and 46.9% were submitted to the conservative treatment with intralesional triamcinolone injections. Among patients submitted to conservative treatment, 60% (n = 9) showed favorable response. CTR expression was observed in 68.51%, and GR in 94.44% of the total sample. There were no differences in the expression of CTR, neither GR in mononucleated stromal cells (MSCs) or multinucleated giant cells (MGCs), in relation to aggressiveness, treatment performed for and the response to conservative treatment. Both markers showed a positive correlation between their expression in MSCs and MGCs in the total sample (P < 0.0001). CTR expression on MSCs showed a positive correlation with MGCs in the aggressive and non-aggressive groups (P < 0.0001). CONCLUSIONS: Calcitonin receptor and GR expression were diffuse and similar in non-aggressive and aggressive cases, and it did not influence the response to clinical treatment with triamcinolone in the sample studied.

Multinucleated giant cell reaction in lower lip squamous cell carcinoma: a clinical, morphological, and immunohistochemical study.

BACKGROUND: Multinucleated giant cell (MGC) reactions have been identified in several malignancies, but their frequency and significance in lower lip squamous cell carcinoma (SCC) are not established. This study evaluated the MGC reactions and their association with clinicopathological parameters in lower lip SCCs. The polarization profile of these cells (M1 or M2 macrophages) was also assessed. METHODS: The presence and distribution of MGC reactions in high-power fields (400×) were evaluated in hematoxylin/eosin-stained histological sections of 91 lower lip SCCs. The histopathological grade of malignancy was evaluated using two grading systems (World Health Organization [WHO] and Malignancy Grading of the Deep Invasive Margins). The histiocytic nature (CD68) and polarization profile (M1-HLA-DR+ or M2-CD163+) of MGCs were evaluated by immunohistochemistry. RESULTS: Multinucleated giant cell reaction was identified in 36 (39.6%) cases, and its frequency was 3.3 times higher in well/moderately differentiated tumors than in poorly differentiated tumors (WHO grading system) (P = 0.006). For Malignancy Grading of the Deep Invasive Margins, the frequency was 2.03 times higher in highly/moderately keratinized tumors than in tumors with minimal/no keratinization (P = 0.012). No significant associations were observed between the presence/distribution of MGCs and clinical parameters (tumor size, lymph node metastasis, distant metastasis, and clinical stage) (P > 0.05). All MGCs were positive for CD68 and there was a predominance of HLA-DR+ over CD163+ MGCs (P = 0.031). CONCLUSIONS: Multinucleated giant cell reactions may not be involved in tumor progression in lower lip SCCs. In this microenvironment, MGCs tend to exhibit a predominantly M1 phenotype and may represent a foreign body reaction to SCC keratin pearls.

Pattern of galectins expression in actinic cheilitis with different risks of malignant transformation.

BACKGROUND: Actinic cheilitis (AC) is a chronic inflammatory lesion that in some situations can turn into squamous cell carcinoma of the lip. The molecular mechanisms involved in this process are not yet completely understood. This study aimed to investigate the expression pattern of galectins in actinic cheilitis according to the histopathological grading. METHODS: Immunoexpression of galectin-1, galectin-3, galectin-7, and galectin-9 was semiquantitatively analyzed in 65 cases of actinic cheilitis graded as low risk (n = 40) or high risk (n = 25) of malignant transformation. Association between the location of the galectins in the cellular compartments and histopathological grading was analyzed. RESULTS: Galectin-1 was mainly observed in the cell cytoplasm, and was elevated (score 3) in 60% of cases, regardless of the histopathological grade (P > 0.05). Galectin-3 expression was higher in high-risk group than in the low-risk group (P < 0.05), with a predominant expression in the cytoplasm and nucleus of low-risk (67.5%), and only in the cytoplasm of high-risk cases (60%) (P < 0.05). Galectin-7 expression did not show significant differences between low-risk and high-risk groups (P > 0.05). With respect to galectin-9, 89.2% of cases were positive, showing decrease in median of scores as there was an increase in histological grade (P < 0.001), with predominant expression in the nucleus and cytoplasm. CONCLUSIONS: This study is the first indication of galectins involvement in the pathogenesis and morphologic progression of actinic cheilitis, particularly galectin-3 and galectin-9.

Hamartomas, choristomas, and teratomas of the oral cavity: A 49-years cross-sectional study in an oral diagnostic service.

BACKGROUND: To investigate the incidence and demographic profile of hamartomatous, choristomatous, and teratoid lesions in a Brazilian population over a 49 years-period. METHODS: A retrospective cross-sectional study was performed, and data regarding demographic and clinical aspects were obtained from the medical records of a [removed for blind peer review] referral center (1970-2019). The collected data were submitted to descriptive analysis and Pearson's chi-square, Fisher's exact, and Kruskal-Wallis tests (p ≤ 0.05). RESULTS: In a total of 16,412 medical records analyzed, 300 (1.83 %) were hamartomatous, 2 (0.01 %) choristomatous, and 1 (0.01 %) teratoid lesions. Hamartomas were most diagnosed in females and adults. Statistical significance was observed between hamartoma and age group (p < 0.001). Odontoma was the most frequent hamartomatous lesion. In choristomatous and teratoid lesions, there was no occurrence in males. The jaws were the most affected anatomical site by hamartoma. Choristomas were observed on the mandible and tongue, while a teratoid lesion was seen on the floor of the mouth. CONCLUSIONS: Low occurrence of choristomatous and teratoid lesions over hamartomatous lesions and a heterogeneous occurrence profile regarding sex, age group, and anatomic site were observed. Hamartomas are relatively common and benign conditions that may cause damage and require special care during dental treatment. Thus, the dentist needs to be able to identify and treat them appropriately. Likewise, although choristomas and teratomas present no risk to patients and have a lower occurrence than hamartomas, they also require treatment.

Immunohistochemical analysis of mismatch proteins in carcinogenesis of the lower lip.

AIM: This study investigated the immunohistochemical expression of hMLH1 and hMSH2 proteins in lower lip squamous cell carcinoma (SCC) and actinic cheilitis (AC), to contribute to the understanding of the development of lower lip cancer. METHODS AND RESULTS: Forty cases of lower lip AC and SCC were studied. Quantitative immunohistochemical analysis was undertaken by counting 1000 cells (positive and negative) in each lesion. Statistical evaluation included Student's t-test and one-way ANOVA. For SCC and AC, the mean number of hMLH1- and hMSH2-positive cells decreased with advanced stage of the lesion. The largest mean number of immunostained cells was observed in AC cases without dysplasia or with mild dysplasia (hMLH1: 721.23 ± 88.116; hMHS2: 781.50 ± 156.93). Intermediate values were obtained for AC with moderate or severe dysplasia (hMLH1: 532.86 ± 197.72; hMHS2: 611.14 ± 172.48). Lower lip SSCs presented the smallest number of positive cells (hMLH1: 255.03 ± 199.47; hMHS2: 518.38 ± 265.68). A statistically significant difference was observed between groups (P < 0.001). CONCLUSIONS: The results support the hypothesis that changes in the immunoexpression of these mismatch proteins are related to the process of carcinogenesis of the lower lip.

Immunoexpression of HSP27 does not seem to influence the prognosis of oral tongue squamous cell carcinoma.

New methods of early detection and risk assessment have been studied aiming to predict the prognosis of patients and directing a specialized treatment of the oral tongue squamous cell carcinoma (OTSCC). In this context, several molecular biomarkers have been investigated for this purpose, and, among them, the heat shock protein 27 (HSP27) can be named. The study aimed to analyze whether heat shock protein 27 (HSP27) exerts any influence on OTSCC, correlating its immunoexpression with clinicopathological parameters, and patient survival. The sample comprised 55 OTSCC cases and 20 normal oral mucosa specimens. The malignancy grading systems proposed by the WHO in 2005, Brandwein-Gensler et al., and Almangush et al. were applied in a histomorphological study. HSP27 expressions were evaluated through the Immunoreactivity Score System (IRS). Significant values were considered at p <0.05 for all statistical tests. Higher IRS results were observed for normal oral mucosa specimens when compared to OTSCC cases (p <0.001). No significant associations between HSP27 immunostaining, the analyzed clinicopathological parameters and patient survival were observed. The results of the present study indicate lower HSP27 expression in OTSCC cases compared to normal oral mucosa specimens. Thus, HSP27 expression does not seem to influence patient prognosis.

Morphological analysis of cell cannibalism: An auxiliary tool in the prediction of central giant cell granuloma clinical behavior.

Central giant cell granuloma (CGCG) is a benign jaw lesion with variable clinical behavior. Cell cannibalism is a cellular process associated with aggressiveness and invasion in malignant neoplasms. Here, we morphologically investigated cell cannibalism as an auxiliary method to predict CGCG clinical behavior. Cell cannibalism was quantitatively evaluated in 19 cases of peripheral giant cell granuloma (PGCG), 38 cases of CGCG (non-aggressive and aggressive), and 19 cases of giant cell tumor of bone (GCT) stained with hematoxylin and eosin. T-test was performed to assess the differences between the variables analyzed (p ≤ 0.05). Cell cannibalism was identified in 21% of non-aggressive CGCGs and 68.4% of aggressive CGCGs. A significantly higher amount of cannibal multinucleated giant cells (CMGC) was observed in aggressive CGCG compared to PGCG and non-aggressive CGCG (p = 0.042; p = 0.044, respectively). There were no significant differences in the CMGC index between non-aggressive CGCG and PGCG (p = 0.858) and between aggressive CGCG and GCT (p = 0.069). CGGC cases that exhibited rapid growth and tooth displacement and/or root resorption had a higher amount of CMGC (p = 0.035; p = 0.041, respectively). Cell cannibalism can be identified in CGCG through routine anatomopathological examination. The quantification of CMGC can help to predict the clinical behavior of central giant cell granuloma.

Clinical pathological analysis of nine cases of aneurysmal bone cyst of the jaws in a Brazilian population.

Aneurysmal bone cysts (ABCs) are benign osteolytic lesions that occur rarely in the jaws. The aim of this study was to investigate the clinical, radiographical and pathological features of ABCs of the jaws. A retrospective analysis of the content of a 39-year database, including nine cases of ABCs of the jaws diagnosed from the archives of the Oral Pathology Service. Nine patients (3 males and 6 females), ranging in age from 5 to 33 years were included. Seven (7/9) lesions were located in the mandible and two (2/9) in the maxilla. A painful swelling was the most common clinical finding (n = 4, 4/9). Radiologically, the lesions frequently presented as multilocular (5/9), well defined (4/9), bone expansion and perforation (2/9). Pathological analysis revealed that two cases were associated with central ossifying fibroma and one case with central giant cell lesion. Histomorphology showed a predominance of the solid type (5/9) and of sinusoidal pseudocystic spaces (4/9). Giant cells, osteoid material, calcified material, blood vessels and hemosiderin deposits were observed in 6/9, 7/9, 8/9, 9/9 and 7/9, respectively. The patients with ABCs presented clinical and radiographical features, which often posed a diagnostic dilemma. Knowledge about the most common characteristics of ABCs may contribute to the establishment of a more accurate diagnosis.

DNA damage through oxidative stress is an important event in oral leukoplakia.

OBJECTIVE: To evaluate the oxidative DNA damage, through 8-hydroxy-2'-deoxyguanosine (8-OHdG), and its repair by base excision repair pathway [Redox factor-1 (Ref-1); X-ray Repair Cross Complementing-1 (XRCC-1)] in different epithelial dysplasia degrees in oral leukoplakia. DESIGN: Forty-four cases of oral leukoplakia and 10 normal oral mucosa were quantified for 8-OHdG, Ref-1, and XRCC-1 through immunohistochemistry. RESULTS: Cytoplasmic 8-OHdG and nuclear XRCC-1 were significantly associated with multiple synchronous lesions (p = 0.048; p = 0.034, respectively). Nuclear Ref-1 was significantly associated with oral leukoplakia on the tongue (p = 0.027). A significantly gradual cytoplasmic 8-OHdG expression increase was observed between normal oral mucosa and epithelial dysplasia (p < 0.05). Nuclear Ref-1 expression was significantly lower (p < 0.01) in non-dysplasia/mild dysplasia, while its cytoplasmic expression was significantly higher in non-dysplasia/mild dysplasia compared to moderate/severe dysplasia and normal oral mucosa (p = 0.03; p < 0.0001, respectively). A significantly higher cytoplasmic XRCC-1 expression was observed in non-dysplasia/mild and moderate/severe dysplasia compared to normal oral mucosa (p < 0.0001; p < 0.0001, respectively). All epithelial dysplasia degrees showed a correlation between nuclear and cytoplasmic expression of these proteins (p < 0.05). CONCLUSIONS: 8-OHdG formation may not play a role in the development of multiple synchronous oral leukoplakias. However, it is related to the severity of the epithelial dysplasia. The subcellular level of Ref-1 implies different roles according to the degree of epithelial dysplasia. Cytoplasmic XRCC-1 expression indicates a possible failure of the DNA repair mechanism and occurs in early morphological stages of epithelial dysplasia.

Necrotizing sialometaplasia: A report of two cases and review of the literature.

Necrotizing sialometaplasia (NS) affects salivary glands, and despite being a benign condition, its clinical and histopathological features sometimes mimic other malignant pathologies of epithelial origin. This article presents two cases of NS and discusses clinicopathological features and the differential diagnosis of this condition. The first case, a 76-year-old woman with a 6-month history of painful oral thrush. Intraoral examination showed an ulcerative lesion located on the hard palate. The clinical hypothesis was squamous cell carcinoma. Second, a 26-year-old man with a 40-days ulcerative lesion on the soft palate. Intraoral examination revealed a reddish ulcer measuring 0.5 cm. Clinical hypothesis was traumatic ulcer. In both cases, a biopsy was performed, and a histopathological diagnosis of NS was established. NS cause is poorly understood, and its clinical features resemble other oral lesions with ulcerative aspects. Thus, dentists must be aware of the clinical features of oral ulcers with more than a 2-week duration without defined etiology.

Central odontogenic fibroma.

Odontogenic fibroma (OF) is a benign odontogenic tumor characterized by various amounts of odontogenic epithelium in a mature fibrous stroma. Two variants can be distinguished: an intraosseous or central OF (COF) and an extraosseous or peripheral. The intraosseous variant is an extremely rare tumor that presents clinical, radiographic, and histopathologic variable findings. A thorough review of the English literature revealed 78 cases of COF so far. Thus, we report an additional case of COF occurring in the maxilla of a 36-year-old woman. In addition, we performed a brief description and discussion of the cases reported in the maxilla and mandible.

Epidemiology and correlation of the clinicopathological features in oral epithelial dysplasia: analysis of 173 cases.

Oral epithelial dysplasias (OEDs) are potentially malignant disorders characterized by diverse degrees of cellular atypia. The early and careful diagnosis has extreme importance, allowing prevention of the progression to the oral squamous cell carcinoma. This study aimed to determine the epidemiology and then correlate it with the clinicopathological features of OED. One hundred seventy-three cases of oral lesions retrieved from the files of a Service of Pathological Anatomy, covering a 38-year period, were submitted to descriptive statistical analysis through the Pearson χ(2) test. The majority of cases were from affected females (57.9%), with a peak of occurrence in the age group of 41 and 55 years (37.3%), white patients (64.8%), and those with lesions located on the gingiva/alveolar ridge (25.1%). The lesions predominantly presented with white color (56.8%) and were described as nodules (27.4%), with a rough surface (76.7%), an exophytic growth (79.1%), and a sessile base (95.6%). The majority of the lesions with degree of mild (34.6%) and moderate (34.9%) OED had clinical diagnosis of leukoplakia, whereas 33.3% of the lesions with degree of severe had clinical diagnosis of squamous cell carcinoma (P < .05). Tobacco use was the risk habit more related with OED (42.6%) (P > .05). The knowledge of OED epidemiology and clinical features provide a better understanding of the factors that possibly are associated with the malignant transformation of OED. Furthermore, these results contribute to supporting a prompt and accurate recognition of these lesions in clinical practice.

Survival-related epithelial-mesenchymal transition proteins in oropharyngeal squamous cell carcinoma: A systematic review and meta-analysis.

OBJECTIVE: To aim of this systematic review was to explore the relationship between Human papillomavirus (HPV) and epithelial-mesenchymal transition (EMT) related to the prognosis of oropharyngeal squamous cell carcinoma (OPSCC). DESIGN: For this systematic review, searches were performed in PubMed, Web of Science, Scopus, Science Direct, and Cochrane, and a random-effects model was used for meta-analysis. The presence of EMT was confirmed by the loss of E-cadherin immunoexpression and overexpression of vimentin. RESULTS: In summary, EMT-related proteins were expressed regardless of HPV status; however, overall survival was better in HPV-positive OPSCC cases, with a 5.88 times lower death risk compared to HPV-negative patients (OR=0.17; 95%CI=0.10-0.30). Likewise, the maintenance of E-cadherin in OPSCC was associated with an 11.11 times lower risk of death due to the disease (OR=0.09; 95%CI=0.01-0.88). CONCLUSIONS: More advanced clinical stages (III/IV) and the presence of lymph node metastases (N1-3) were common in OPSCC but were not significantly associated with HPV status.

Assessment of the presence of interleukin 17+ macrophages and Th17 cells in situ in lip and oral tongue cancer.

Increasing clinical evidence indicates that Th17 cells may promote or inhibit tumor progression, however the exact role of these cells in Oral Squamous Cell Carcinoma (OSCCs) pathogenesis and progression remains unclear. Tumor associated macrophages are highly plastic phenotype cells which can differentiate as M1 or M2. The mechanism and cellular phenotype of IL-17 expressing macrophages are unknown. 40 cases of lip and 28 of tongue SCCs were submitted to immunohistochemical analysis, and histologically graded. In tongue cases TNM was analyzed. The number of IL-17+ T cells was higher in lip SCC (p = 0.028). IL-17+ macrophages was greater in tongue SCC (p = 0.014). There were more IL-17+ macrophages in the high-grade malignancy oral tongue SCCs (p = 0.016), yet there was no significant difference in the numbers of RORγt+ lymphocytes by histopathological or TNM analysis. This study provides evidence concerning IL-17's pleiotropic roles, being possibly dependent on its cellular sources in the tumor microenvironment.

Analysis of local immunity in squamous cell carcinoma of the tongue and lower lip.

Antitumor immunity plays an important role in the development of and protection against malignancy. In general, patients with cancer are known to be immunologically compromised. The objective of this study was to evaluate local immunity in squamous cell carcinomas (SCCs) of the tongue and lower lip by immunohistochemistry, using anti-CD3, -CD4, -CD8, -CD25 and -zeta antibodies. Immunoexpression at the invasive front was compared considering anatomical tumor location and metastasis. The CD4/CD8 ratio was calculated for each case and associated with the variables. CD3+, CD4+, CD8+ and CD25+ cell counts were higher in SCCs of the lower lip and anti-zeta immunostaining was more evident in non-metastatic cases. CD8+ and CD25+ cell counts were also significantly correlated with tumor location (p=0.004 and p=0.004, respectively), with the observation of a larger number of these cells in SCCs of the lower lip. The CD4/CD8 ratio showed no significant association with metastasis or anatomical location. In conclusion, the clinical behavior of the oral SCC cases studied might be partially related to the immunohistochemical profile of the inflammatory infiltrate present at the invasive front.

Elastofibromatous change of the oral mucosa: case report and literature review.

Elastofibroma is an uncommon fibrous pseudotumor that usually occurs in the subscapular region of middle-aged and older adults. Since its seminal description, cases of elastofibroma or elastofibroma-like proliferations have been identified at several anatomic locations, including the foot, hand, thigh, olecranon, gastrointestinal tract, trachea, dorsal spine and eye. Involvement of the oral cavity is rare, with only four cases reported to date. Herein, we report a case of elastofibromatous change in the soft palate of a 55-year-old man and review the literature regarding pathogenesis, clinicopathologic features, differential diagnosis and management.

Lipomas of the oral cavity: clinical and histopathologic study of 41 cases in a Brazilian population.

This study evaluated the clinical and histopathologic aspects of 41 cases of oral lipomas diagnosed in a Brazilian population. All records from patients diagnosed with oral lipoma between 1970 and 2008 were reviewed. Histological sections were evaluated by light microscopy. There was a predominance of females (2.4:1), with a peak incidence between the sixth and seventh decade. The buccal mucosa was the most affected site (53.7%), followed by the buccal sulcus (14.6%) and tongue (9.8%). Tumor size ranged from 0.5 to 10 cm and the mean reported duration was 48 months. Histologically, the following variants were identified: lipoma (41.5%), fibrolipoma (34.1%), spindle cell lipoma (9.8%), sialolipoma (9.8%), osteolipoma (2.4%), and chondrolipoma (2.4%). Most tumors were well delimited, irrespective of the variant. Lipomas are rare tumors of the oral cavity. The characterization of new variants, such as sialolipomas, and the identification of histological subtypes in already known variants, such as low-fat and fat-free spindle cell lipomas, highlight the importance for careful microscopic evaluation of these tumors, which might be combined with immunohistochemistry in some cases.

Aggressive spindle cell rhabdomyosarcoma in an 11-month-old boxer dog.

Rhabdomyosarcoma (RMS) is a malignant neoplasm derived from mesenchymal tissue with a tendency toward myogenic differentiation associated with the embryogenesis of skeletal muscle. According to the histological features, it can be classified in embryonal, botryoid, alveolar, and pleomorphic, which usually correspond to clinical behavior and prognosis. The spindle cell (SCRMS) variant is a rare subtype of the embryonal RMS and is considered to be less aggressive lesion. The aim of the present paper is to report an unusual case of SCRMS in an 11-month-old male boxer dog diagnosed as extensive SCRMS that affected the frontal region of the skull. Due to the aggressive nature of the lesion and poor clinical prognosis the dog's owners preferred euthanasia as a treatment. A full postmortem examination was carried out. Microscopically, the lesion was composed of a highly cellular proliferation of spindle cells arranged in long and intersecting fascicles. After performing the immunohistochemical studies (HHF-35, smooth muscle actin, desmin and MyoD1), the present case was diagnosed as SCRMS.

Myofibroma of the oral cavity. A rare spindle cell neoplasm.

Myofibroma is an uncommon spindle cell neoplasm rarely found in oral cavity. Typically, this lesion is seen in neonates and infants with few cases reported in adults patients. In the oral cavity, myofibroma occurs within the submucosal or intramuscular tissue and has a predilection by the tongue, buccal mucosa and lips. Microscopically, a typical biphasic pattern can be observed. Misdiagnosis included benign and malignant spindle cell lesions of nerve tissue or smooth muscle origin, such as neurofibroma, leiomyoma and sarcomas. Thus, immunohistochemical staining is a useful tool to identify the nature of neoplastic cells and to reach an accurate diagnosis. An immunohistochemical panel consisting of antibodies to vimentin, SMA, HHF-35, S-100p and desmin must be achieved. In most cases, positivity for vimentin, SMA and HHF-25 can be observed. Our report describes a solitary myofibroma of the tongue of a 23-year-old man with emphasis in clinical, histopathological and immunohistochemical features of this lesion.

Ossifying fibromyxoid tumor in the mandibular gingiva: case report and review of the literature.

BACKGROUND: Ossifying fibromyxoid tumors (OFTs) are uncommon soft tissue neoplasms. Only one case arising in the gingiva has been described. METHODS: A 21-year-old woman presented with a painless exophytic mass located in the right posterior mandibular gingiva, which was identified 6 months earlier. Radiographs showed irregular calcifications inside the lesion, discrete irregularity of alveolar bone, and integrity of buccal and lingual cortical bone. An incisional biopsy was performed based on the clinical diagnostic hypothesis of peripheral ossifying fibroma or peripheral giant cell granuloma. Microscopic features were compatible with the diagnosis of ossifying fibroma. The entire mass was excised and submitted to histopathologic and immunohistochemical analysis. RESULTS: Histopathologic analysis revealed proliferation of round to spindle-shaped cells arranged in cords and nests and embedded in a fibromyxoid matrix. An incomplete shell of bone trabeculae located beneath the fibrous pseudocapsule was observed at the periphery. Immunohistochemical analysis showed positivity for vimentin and S-100 protein and negativity for smooth muscle actin, muscle-specific actin, and glial fibrillary acidic protein. The definitive diagnosis was OFT. The patient showed no clinical signs of recurrence 7 months after surgical excision. CONCLUSIONS: OFTs located in the gingiva are extremely rare. At this site, these tumors are clinically indistinguishable from other reactive or neoplastic lesions. Although many cases present an indolent biologic behavior, the local recurrence of OFTs has been reported; therefore, long-term follow-up is mandatory.