A rare case of oral squamous cell carcinoma in a patient with Cowden syndrome: Association or coincidence?

Cowden Syndrome (CS) is a rare genetic disease caused by mutations in the PTEN tumor suppressor gene, often presenting a challenging diagnosis due to its diverse clinical manifestations. Although extensively linked to several types of cancer, the precise association between CS and oral malignancies, particularly squamous cell carcinoma (SCC), remains poorly understood. This report describes a unique case of late diagnosis of CS in a 53-year-old female patient who later developed SCC in the inferior alveolar ridge, even without exposure to classic risk factors. The need to increase awareness in the medical and dental communities about CS and its manifestations in the oral cavity is highlighted. Early recognition and management of conditions associated with CS have a significant impact on patients' quality of life. Encouraging the publication of similar cases is recommended to encourage detailed analyzes and investigations in order to better understand the possible association between the syndrome and the development of malignancies in the oral cavity.

Evaluation of the presence of Th1 response through T-bet and IFN-gamma immunohistochemical expression in lower lip and oral tongue squamous cell carcinomas.

INTRODUCTION: Evaluate the immunohistochemical expression of T-bet and IFN-γ in lower lip (LLSCC) and oral tongue squamous cell carcinoma (OTSCC), verifying the presence of Th1 responses in lesions with different clinical conditions. METHODS AND MATERIALS: Thirty OTSCC and 30 LLSCC were analyzed by immunohistochemistry. T-bet was quantitatively assessed by parenchyma cell and stroma quantification, and IFN-γ was semi-quantitatively analyzed: 1:0-25%; 2:26-50%; 3:51-75%; 4:> 75% immunopositive cells. Histological differentiation degrees were categorized as well differentiated (WD), moderately differentiated (MD), or poorly differentiated (PD). RESULTS: OTSCC presented the highest number of T-bet+, parenchyma (p: 0.006), stroma (p: 0.156), parenchyma/stroma (p: 0.015), with no relationship to histological malignancy grade. IFN-γ higher concentrations in LLSCC were detected in parenchyma, stroma and in parenchyma/stroma (p: 0.000), as well as greater immunoreactivity in WD and MD (p: 0.001). In OTSCC, a positive and statistically significant correlation was observed between T-bet+ in parenchyma and IFN-γ in stroma(r: 0.388; p: 0.034), in addition to a statistically significant positive correlation between T-bet in parenchyma compared to stroma(r: 0.411; p: 0.024) and for IFN-γ in both parenchyma and stroma(r: 0.775; p: 0.000) in LLSCC. Higher T-bet+ was observed in OTSCCs, although higher IFN-γ was detected in LLSCCs. CONCLUSION: Thus, we suggest that, even though LLSCC presented lower T-bet+, the favorable microenvironment in these lesions led to an expressive activation of IFN-γ by T-bet+, considerably acting on Th1 differentiation and in antitumor activity, which, admittedly, present less aggressive behavior, reinforcing once again the important role of this cytokine and its use in strategy to fight cancer.

A retrospective multicenter study of oral and maxillofacial lesions in older people.

Few studies on the distribution of oral diseases in older people are available in the literature. This study aimed to investigate the prevalence and demographic characteristics of oral and maxillofacial lesions in geriatric patients (age ≥ 60 years). A retrospective descriptive cross-sectional study was performed. Biopsy records were obtained from archives of three Brazilian oral pathology centers over a 20-year period. Data on sex, age, anatomical site, skin color, and histopathological diagnosis were collected and analyzed. Pearson's chi-square test was used to evaluate differences in the frequency of the different oral and maxillofacial lesion groups. A total of 7,476 biopsy records of older patients were analyzed. Most cases were diagnosed in patients aged 60 to 69 years (n = 4,487; 60.0%). Females were more affected (n = 4,403; 58.9%) with a female-to-male ratio of 1:0.7 (p < 0.001). The tongue (n = 1,196; 16.4%), lower lip (n = 1,005; 13.8%), and buccal mucosa (n = 997; 13.7%) were the most common anatomical sites. Reactive and inflammatory lesions (n = 3,840; 51.3%) were the most prevalent non-neoplastic pathologies (p < 0.001), followed by cysts (n = 475; 6.4%). Malignant neoplasms were more frequent (n = 1,353; 18.1%) than benign neoplasms (n = 512; 6.8%). Fibrous/fibroepithelial hyperplasia (n = 2,042; 53.2%) (p < 0.001) and squamous cell carcinoma (n = 1,191; 88.03%) (p < 0.001) were the most common oral lesions in older adults. Biopsy data allow the accurate characterization of the prevalence of oral and maxillofacial lesions, supporting the development of public health policies that can enable the prevention, early diagnosis, and appropriate treatment of these lesions. Also, they bring valuable information that helps dentists and geriatricians diagnose these diseases.

Clinicopathologic analysis of oral dermoid and epidermoid cysts: a Brazilian multicenter study.

Dermoid cysts (DCs) and epidermoid cysts (ECs) are uncommon developmental cysts affecting the oral cavity. This study aims to evaluate patients with oral DCs and ECs and their demographic and clinicopathologic features. A retrospective descriptive cross-sectional study was performed. A total of 105,077 biopsy records of oral and maxillofacial lesions from seven Brazilian oral pathology centers were analyzed. All cases diagnosed as oral DCs and ECs were reviewed, and clinical, demographic, and histopathological data were collected. The series comprised 32 DCs (31.4%) and 70 ECs (68.6%). Most of the DCs occurred on the floor of the mouth (n = 14; 45.2%) of women (n = 17; 53.1%) with a mean age of 34.6 ± 21.6 years. All DCs were lined partially or entirely by stratified squamous epithelium (100%). Chronic inflammatory cells, melanin pigmentation, multinucleated giant cell reaction, and cholesterol clefts were observed in the fibrous capsule . Most of the ECs affected the labial mucosa (n = 20; 31.7%) of men (n = 39; 56.5%) with a mean age of 48.0±19.8 years. Microscopically, most ECs (n = 68; 97.1%) were lined entirely by stratified squamous epithelium. Two cysts (2.9%) showed areas of respiratory metaplasia. Chronic inflammatory cells, melanin pigmentation, multinucleated giant cell reaction, and cholesterol clefts were also observed in the fibrous capsule. Conservative surgical excision was the treatment of choice in all cases. Oral DCs and ECs are uncommon and often clinically misdiagnosed lesions. Clinicians should consider DCs and ECs in the differential diagnosis of soft tissue lesions in the oral cavity, mainly located on the floor of the mouth and labial mucosa.

Maxillary Surgical Ciliated Cyst After Orthognathic Surgery.

Surgical ciliated cysts, also known as implantation cysts or postoperative maxillary cysts, are uncommon cystic formations predominantly arising in the posterior maxillary region after radical maxillary sinus surgery. Herein, we present the case of a 28-year-old male patient who had previously undergone orthognathic surgery and later experienced a minor car accident without major consequences. Approximately four years after surgery, the patient sought dental care due to the presence of a painless swelling in the maxillary region. Upon intraoral examination, the swelling extended from the area around the right canine to the upper left molar, covered by red mucosa. Image studies revealed an extensive well-defined osteolytic lesion causing thinning, erosion, buccal cortical plate perforation, and root resorption. An incisional biopsy was performed, and microscopic examination revealed a cystic lesion lined by ciliated respiratory-type epithelium and capsule variably fibrotic with sparse chronic inflammation. The final diagnosis was surgical ciliated cysts. The treatment approach involved decompression followed by enucleation and curettage, with the addition of bone grafting and the application of Leukocyte-Platelet Rich Fibrin (L-PRF). The patient has been under clinical follow-up for approximately 17 months with no signs of recurrence. A careful morphological evaluation is essential to avoid misdiagnosis and ensure a satisfactory treatment approach. In conclusion, this case highlights the importance of accurate diagnosis and appropriate treatment approaches for surgical ciliated cysts to ensure favorable patient outcomes.

A destructive sinonasal organizing hematoma mimicking malignancy.

Sinonasal organizing hematomas (SOH) are rare, benign lesions that can be mistaken for malignancies due to their unfamiliarity among clinicians and aggressive appearance on imaging, which can lead to aggressive and unnecessary therapeutic interventions. Herein, we report an unusual case of SOH in an 87-year-old female patient who sought care at a maxillofacial surgery service due to persistent right nasal obstruction and imaging findings that suggested the possibility of sinonasal malignancy. We highlight the importance of recognizing these lesions to ensure adequate treatment through a conservative approach.

Basal cell adenocarcinoma of the soft palate: A closer look for an exceedingly rare salivary gland tumor.

Basal cell adenocarcinoma (BCAd) is an extremely rare primary biphasic carcinoma of the salivary glands with few well-documented cases reported in the literature. Herein, we report a rare case of a 44-year-old male patient who presented an oral medicine service with an erythematous nodular lesion on the soft palate, measuring 1.5 cm in its largest diameter, with a 5-year duration. The clinical diagnosis was pleomorphic adenoma, and an excisional biopsy was performed. Histopathological analysis revealed a biphasic infiltrative tumor composed of a mixture of central ductal cells and abluminal basal cells with slight atypia arranged in solid, trabecular, tubular and cribriform growth patterns in a loose stroma. The peripheral cells show a palisading arrangement with round hyperchromatic nuclei and scanty cytoplasm. Occasional mitotic figures were seen. Few spindle-shaped cells suggestive of myoepithelial cells were present in the stroma surrounding the basaloid tumor nests. The diagnosis was BCAd. The patient was referred to a head and neck service and has been followed up for 8 months with no signs of recurrence. In conclusion, although the diagnosis of BCAd can be challenging due to its rarity and morphological overlap with other salivary gland lesions, a meticulous morphological assessment is key for accurate diagnosis, especially in cases originating from minor salivary glands. Surgical excision with a wide safety margin is the treatment of choice and long-term follow-up is recommended to monitor possible recurrences.

Oral melanoacanthoma: Clinicopathological and immunohistochemical features of a case series and a scoping review.

BACKGROUND: This study presents a case series and scoping review of oral melanoacanthoma to examine its clinical, histopathological, and immunohistochemical characteristics. METHODS: Nine cases of oral melanoacanthoma were included in the case series. Clinical data were collected from biopsy charts. Hematoxylin-eosin and immunohistochemistry for TRP2, CD3, and CD20 were done. For the scoping review, MEDLINE/PubMed, Web of Science, EMBASE, and Scopus were searched. RESULTS: Case series: The mean age was 46.8 years (female-to-male ratio 2:1). Lesion's mean size was 11.0 mm (±9.3). Lesions were mainly macular (77.8%) with brown or black coloration (88.9%) and often affected multiple sites (44.4%). The evolution time ranged from 15 days to 96 months. Lesions commonly showed epithelial acanthosis (66.7%), spongiosis (55.6%), exocytosis (77.8%), melanin incontinence (88.9%), and inflammatory infiltrate in the lamina propria (77.8%), from which all showed lymphocytes. TRP2-positive melanocytes were identified in the basal and spinous layer of all cases, and in the superficial layer of three cases. CD3-positive cells predominate over the CD20-positive. Scoping review: 85 cases of oral melanoacanthoma were retrieved from 55 studies. Patients were primarily female (female-to-male ratio 2.2:1), black-skinned (64.1%), with a mean age of 36.13 (± 17.24). Lesions were flat (81.9%), often brown (62.4%). Buccal mucosa was the preferred site (32.9%), followed by multiple sites (28.2%). CONCLUSION: Oral melanoacanthoma mainly affects women across a wide age range, with lesions commonly appearing as brown/black macules, particularly on the buccal mucosa. TRP2-positive melanocytes and T-lymphocytes were consistently found and could participate in oral melanoacanthoma pathogenesis.

Oral solitary fibrous tumors: A collaborative clinicopathologic study of 19 cases.

OBJECTIVE: To report the clinicopathologic features of 19 oral solitary fibrous tumors (SFTs). METHODS: Clinical data were collected from the records of seven pathology services. All cases were re-evaluated by HE staining and confirmed by immunohistochemistry. RESULTS: The series comprised 11 females (57.9%) and 8 males (42.1%), with a mean age of 47.3 ± 14.7 years (range: 22-71 years) and a 1.3:1 female-to-male ratio. Most tumors affected the buccal mucosa (n = 7; 36.8%) and presented clinically as an asymptomatic solitary submucosal well-circumscribed nodule with coloration similar to the oral mucosa. Morphologically, most SFTs (n = 10; 52.6%) exhibited a classic hybrid pattern characterized by a well-circumscribed proliferation of densely cellular areas alternating with hypocellular areas in a variably collagenous vascular stroma. Remnants of accessory salivary glands were observed in two cases (n = 2; 10.5%). All tumors were positive for STAT6 and CD34 (n = 19; 100%). Outcome information was available from 6 patients (31.6%), with clinical follow-up ranging from 6 to 24 months (mean ± SD, 9.5 ± 6.8 months), and none developed local recurrence. CONCLUSIONS: Oral SFTs are rare and often clinically misdiagnosed. Pathologists should consider SFT in the differential diagnosis of oral spindle cell tumors. Accurate diagnosis requires careful morphological evaluation supported by immunohistochemical analysis.

Immunoexpression of Autophagy-Related Proteins in Salivary Gland Tumors: An Exploratory Study.

BACKGROUND: Autophagy is a cellular survival mechanism involved in several human diseases, but its participation in the development of salivary gland tumors is not fully understood. This study investigated the immunoexpression of autophagy-related proteins (autophagy-related 7 [Atg7], microtubule-associated protein 1 light chain 3A [LC3A], microtubule-associated protein 1 light chain 3B [LC3B], protein p62 [p62], and phosphorylated mammalian target of rapamycin [p-mTOR]) in pleomorphic adenoma (PA), polymorphous adenocarcinoma (PAC), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (ACC) of salivary glands. METHODS: Twenty PAs, 20 PACs, 20 MECs, and 14 ACCs were selected. The percentages of cytoplasmic and nuclear positivity for autophagy-related proteins in neoplastic cells were assessed and correlated with histopathological parameters. RESULTS: Cytoplasmic immunoexpression of Atg7 was observed in all groups, with high median percentages of positivity. Regarding LC3A and LC3B, cytoplasmic immunoexpression was found in most PACs (95%) and in all cases of PA, MEC and ACC, with the highest percentages of positivity in PACs and PAs (p < 0.005). ACCs exhibited lower cytoplasmic immunoexpression of p-mTOR (p < 0.005) and lower nuclear expression of p62 (p < 0.05) when compared to PAs, PACs and MECs. Low nuclear immunoexpression of Atg7, LC3A and p-mTOR and absence of nuclear staining for LC3B were observed in all groups. Regarding histopathological parameters of PAs, MECs and ACCs, there were no significant differences in the expression of autophagy-related proteins. In all groups, positive correlations were observed between the immunoexpression of some autophagy-related proteins (p < 0.05). CONCLUSIONS: The results suggest the participation of autophagy in the pathogenesis of PA, PAC, MEC, and ACC of salivary glands. Upregulation of autophagy and reduced nuclear translocation of p62 may contribute to the aggressive biological behavior of salivary gland ACC.

Salivary gland tumors: A 13-year clinicopathologic retrospective study in a Brazilian northeast population.

Background: The present study aimed to evaluate the clinicopathologic features of salivary gland tumors (SGTs) in a Brazillian northeast population. Material and Methods: A retrospective descriptive cross-sectional study was performed (1995-2009). All cases of SGTs diagnosed in a private surgical pathology service in Brazil were reviewed, and clinicopathological data were collected. Results: A total of 23.258 histopathological records of biopsies were analyzed, and 174 cases were diagnosed as SGTs (0.7%). Of these, 117 (67.2%) were classified as benign, and 57 (32.8%) were malignant. The series comprised 89 females (51.1%) and 85 males (48.9%), with a mean age of 50.2 years (range: 3-96 years) and a roughly equal female-to-male ratio (1:1). Most tumors occurred in the parotid gland (n = 82, 47.1%), followed by the palate (n = 45, 25.9%), submandibular gland (n = 15, 8.6%). Pleomorphic adenoma (n = 83; 70.9%) and mucoepidermoid carcinoma (n = 19, 33.3%) were the most frequent benign and malignant tumors, respectively. After reevaluation of morphology and immunohistochemical analysis, seven tumors (4.0%) were reclassified following the current WHO Classification of the Head and Neck Tumors. Conclusions: The general features of SGT from the studied Brazilian population were similar to previously published reports in other countries. However, SGTs do not show any sex predilection. Although careful morphological analysis is the key to the correct diagnosis of these tumors, immunohistochemical analysis is essential to establish an accurate diagnosis in the face of challenging cases. Key words:Salivary gland tumors, epidemiology, head and neck pathology.

Diode laser on excision of giant peripheral odontogenic myxoma: a rare case report and literature review.

It was to report a rare case of peripheral odontogenic myxoma removed with high-power diode laser and to do an extensive review of studies of odontogenic cysts and tumors treated with high-power laser (HPL). This is a rare case of a 63-year-old male patient with a peripheral odontogenic myxoma measuring approximately 10 cm in the attached gingiva region of tooth 16 removed with a high-power diode laser (808 nm, 3 W, in continuous mode, under constant suction, with 400-µm optical fiber). A literature review was also carried out looking for articles that involved the use of HPL in the treatment of odontogenic cysts and tumors, without restriction of year or language. In the present case, there was no need for suturing, no postoperative discomfort, and minimal bleeding during the procedure. In a 12-month follow-up period, there were no signs of recurrence. Only two cases of intra-osseous odontogenic myxomas treated with HPL and 10 cases involving other odontogenic cysts and tumors were found. All studies showing HPL to be effective in treating these lesions. Despite the different types of lasers used and different parameters, it is observed that lasers are effective in the treatment of odontogenic lesions.

Lingual metastasis as the first presentation of clear cell renal cell carcinoma: Report of a rare case clinically mimicking a benign lesion.

Metastases in the oral cavity are rare and frequently associated with widespread disease and poor prognosis. Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma (RCC), known for its propensity for metastatic spread. The diagnosis of oral metastases from ccRCC is challenging, especially when the patient has no history of primary neoplasm. Herein, we reported a rare metastatic ccRCC in a 58-year-old female presenting clinically as a painless nodule on the tongue mimicking a benign lesion. Microscopically, the tumor showed a proliferation of clear cells organized in nests with a predominantly lobular arrangement. The dense connective tissue stroma was highly vascularized, exhibiting some areas with a hyalinized aspect. Immunohistochemistry showed focal positivity for pan-cytokeratin AE1/AE3 and strong positivity for CK8, CK18, epithelial membrane antigen (EMA), vimentin, and CD10. S-100 protein, HMB-45, CK7, and CK20 were negative. The definitive diagnosis was metastatic ccRCC. The treatment was initiated with sunitinib. However, the disease progressed, and the patient was submitted to palliative care. Despite the low survival rate of patients with metastases, the clinician's experience in identifying an oral metastatic lesion may reveal undiagnosed primary tumors and provide better prognosis and survival rates.

Immunoexpression of CXCL12 and CXCR4 in Radicular Cysts, Dentigerous Cysts, and Odontogenic Keratocysts.

The aim of this study was to evaluate the immunoexpression of chemokine CXCL12 and its receptor CXCR4 in radicular cysts (RCs), dentigerous cysts (DCs), and odontogenic keratocysts (OKCs), and to correlate the findings with morphologic parameters of RCs (inflammatory infiltrate and cystic epithelium). Twenty RCs, 20 DCs, and 20 OKCs were submitted to immunohistochemistry. The percentages of cytoplasmic (CXCL12 and CXCR4) and nuclear (CXCR4) staining in epithelial and fibrous capsule cells were determined. RCs and DCs exhibited higher epithelial expression of CXCL12 than OKCs ( P <0.05). The expression of CXCL12 in the fibrous capsule was higher in DCs than in RCs and OKCs ( P <0.05). Higher cytoplasmic expression of CXCR4 was observed in the epithelial lining and fibrous capsule of RCs and DCs compared with OKCs ( P <0.05). In the fibrous capsule, DCs exhibited higher nuclear expression of CXCR4 than OKCs ( P <0.05). No significant differences in the immunoexpression of CXCL12 or CXCR4 were observed according to the morphologic parameters of RCs ( P >0.05). Strong positive correlations were found between cytoplasmic and nuclear expression of CXCR4 in the epithelial lining of RCs and DCs and in the fibrous capsule of all groups ( P <0.05). The results suggest the participation of CXCL12 and CXCR4 in the pathogenesis of RCs, DCs, and OKCs. These proteins may be particularly relevant for the development of odontogenic cysts with less aggressive biological behavior, irrespective of their nature (inflammatory or developmental). In RCs, the expression of CXCL12 and CXCR4 may not be related to the intensity of the inflammatory infiltrate or the status of cystic epithelium.

A retrospective multicenter study of oral and maxillofacial lesions in older people

Abstract Few studies on the distribution of oral diseases in older people are available in the literature. This study aimed to investigate the prevalence and demographic characteristics of oral and maxillofacial lesions in geriatric patients (age ≥ 60 years). A retrospective descriptive cross-sectional study was performed. Biopsy records were obtained from archives of three Brazilian oral pathology centers over a 20-year period. Data on sex, age, anatomical site, skin color, and histopathological diagnosis were collected and analyzed. Pearson's chi-square test was used to evaluate differences in the frequency of the different oral and maxillofacial lesion groups. A total of 7,476 biopsy records of older patients were analyzed. Most cases were diagnosed in patients aged 60 to 69 years (n = 4,487; 60.0%). Females were more affected (n = 4,403; 58.9%) with a female-to-male ratio of 1:0.7 (p < 0.001). The tongue (n = 1,196; 16.4%), lower lip (n = 1,005; 13.8%), and buccal mucosa (n = 997; 13.7%) were the most common anatomical sites. Reactive and inflammatory lesions (n = 3,840; 51.3%) were the most prevalent non-neoplastic pathologies (p < 0.001), followed by cysts (n = 475; 6.4%). Malignant neoplasms were more frequent (n = 1,353; 18.1%) than benign neoplasms (n = 512; 6.8%). Fibrous/fibroepithelial hyperplasia (n = 2,042; 53.2%) (p < 0.001) and squamous cell carcinoma (n = 1,191; 88.03%) (p < 0.001) were the most common oral lesions in older adults. Biopsy data allow the accurate characterization of the prevalence of oral and maxillofacial lesions, supporting the development of public health policies that can enable the prevention, early diagnosis, and appropriate treatment of these lesions. Also, they bring valuable information that helps dentists and geriatricians diagnose these diseases.

Clinicopathologic analysis of oral dermoid and epidermoid cysts: a Brazilian multicenter study

Abstract Dermoid cysts (DCs) and epidermoid cysts (ECs) are uncommon developmental cysts affecting the oral cavity. This study aims to evaluate patients with oral DCs and ECs and their demographic and clinicopathologic features. A retrospective descriptive cross-sectional study was performed. A total of 105,077 biopsy records of oral and maxillofacial lesions from seven Brazilian oral pathology centers were analyzed. All cases diagnosed as oral DCs and ECs were reviewed, and clinical, demographic, and histopathological data were collected. The series comprised 32 DCs (31.4%) and 70 ECs (68.6%). Most of the DCs occurred on the floor of the mouth (n = 14; 45.2%) of women (n = 17; 53.1%) with a mean age of 34.6 ± 21.6 years. All DCs were lined partially or entirely by stratified squamous epithelium (100%). Chronic inflammatory cells, melanin pigmentation, multinucleated giant cell reaction, and cholesterol clefts were observed in the fibrous capsule . Most of the ECs affected the labial mucosa (n = 20; 31.7%) of men (n = 39; 56.5%) with a mean age of 48.0±19.8 years. Microscopically, most ECs (n = 68; 97.1%) were lined entirely by stratified squamous epithelium. Two cysts (2.9%) showed areas of respiratory metaplasia. Chronic inflammatory cells, melanin pigmentation, multinucleated giant cell reaction, and cholesterol clefts were also observed in the fibrous capsule. Conservative surgical excision was the treatment of choice in all cases. Oral DCs and ECs are uncommon and often clinically misdiagnosed lesions. Clinicians should consider DCs and ECs in the differential diagnosis of soft tissue lesions in the oral cavity, mainly located on the floor of the mouth and labial mucosa.

Oral mucoceles: A Brazillian Multicenter Study of 1,901 Cases.

Oral mucocele (OM) is the most common lesion of minor salivary glands. The present study aimed to report the clinical and demographic features of a large series of OMs and identify possible predictive variables associated with the recurrence rate of these lesions. A retrospective descriptive cross-sectional study was performed. A total of 43,754 biopsy records from four pathology services in Brazil were analyzed. All cases of OMs were reviewed, and clinical and demographic data were collected. The study comprised 1,002 females (56.2%) and 782 males (43.8%), with a mean age of 19.8±16.4 years (range: 01-87 years) and a 1.3:1 female-to-male ratio. The lower lip (n=1,160; 67.4%), and floor of the mouth (n=172; 10.0%), were the most common affected sites, presenting clinically as nodules (n=978; 79.4%) of smooth surface (n=428; 77.5%) and normal color (n=768, 46.7%). Excisional biopsy was the treatment in most cases (n=1,392; 78.0%). Recurrent OMs represented 6.2% of all diagnosed cases (n=117). OMs recurred more commonly in younger patients (aged<20 years) (p<0.0001), in lesions larger than 2 cm in diameter (p<0.0001), and in those located in the ventral tongue (p=0.0351). Also, recurrence rates were higher significantly in cases treated with laser surgery than in those with conventional surgery (p=0.0005). Patients with OMs should be carefully informed of its possible recurrence, especially when found on the ventral tongue of young patients.