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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presents rapid transmission and significant mortality worldwide. It is responsible for coronavirus disease 2019 (COVID-19). The disease presents diverse clinical symptoms, including fever, cough, dyspnea, and pneumonia. However, other manifestations associated with COVID-19 need to be clarified, leading specialists to an early diagnosis and better prognosis. We describe the spectrum of clinicopathologic COVID-19-related oral lesions that can be the first and/or the unique manifestation of the disease. Fourteen patients with a mean age of 58 years (range: 23 to 88 y) with oral lesions were included. All patients were confirmed to be infected with SARS-CoV-2 by reverse transcription polymerase chain reaction testing. Patients demonstrated mild symptoms, including dysgeusia, anosmia, fever, and headache. The lesions were recognized and classified into 2 groups: (1) lesions caused by ischemia and/or hemorrhage and (2) lesions secondary to inflammatory events associated with viral load. The palate was most affected (n=8), followed by the tongue (n=4), and both the lip and palate (n=2). Histologic analysis demonstrated thrombosis of small arteries and capillaries, associated with areas of hemorrhage and chronic inflammatory infiltrate. Immunohistochemistry showed positive staining for spike protein (SARS-CoV and SARS-CoV-2) and angiotensin-converting enzyme 2 in the surface epithelium, salivary glands, inflammatory cells, and endothelial cells. Although the incidence of oral lesions among patients infected with SARS-CoV-2 appears to be uncommon, these findings suggest that the oral mucosa can also be a target organ for SARS-CoV-2.

Objective The aim of this study was to report the clinicopathologic features of 105 new cases of adenomatoid odontogenic tumor (AOT) from Brazil, Guatemala, Mexico, and South Africa. Study Design Clinical and radiographic data were collected from records of 5 oral pathology laboratories, and all cases were microscopically reviewed. Results This series of cases included 36 (34.2%) from South Africa; 33 (31.4%) from Brazil; 23 (21.9%) from Mexico; and 13 (12.3%) from Guatemala. Seventy-two patients (68.5%) were females and 33 patients (31.4%) were males, with an average age of 19.2 years. The tumors predominantly affected the anterior maxilla (48.5%), followed by the anterior mandible (29.5%); posterior mandible (15.2%); and posterior maxilla (6.6%). Sixty-three tumors (63.6%) were follicular, 34 (34.3%) were extrafollicular, and 2 (2%) were peripheral. In most cases, the tumors caused considerable cortical expansion (average size 3.4 cm). Microscopically, most cases showed rosette-like and duct-like structures. Conclusions This is one of the largest case series of AOTs reported in the literature and the first multicenter study involving populations from Latin America and South Africa. In a fifth of the present cases, the posterior regions of the gnathic bones were affected and the tumors demonstrated larger sizes compared with cases occurring in other populations.

Primordial odontogenic tumor (POT) is a recently described benign odontogenic tumor, with only 16 cases reported in the literature. We present 2 new cases of POT affecting the mandible. Case 1 is that of 12-year-old girl with an asymptomatic, slow-growing mass, causing facial asymmetry. Radiography showed a well-defined unilocular radiolucency surrounding an impacted second premolar. Case 2 is that of a 13-year-old girl with a mass involving the crown of the unerupted third molar and showing similar radiographic features. Microscopically, both lesions were composed of variably cellular fibromyxoid tissue surrounded by thin ameloblastic epithelium, with stellate reticulum-like areas, but no mineralized tissue, yielding the diagnosis of POT. Immunohistochemical analysis showed diffuse expression of CK14 in epithelial cells, whereas CK19 was expressed mainly in the basal layer. Syndecan-1 (CD138) was expressed in the stellate-like regions and in the subepithelial zone. Both patients were treated surgically, with no signs of recurrence seen after 15 and 60 months, respectively.

A proper antibody panel selection is one of the most important factors to reach an adequate diagnosis in challenging cases. This retrospective study was designed to determine the contribution of immunohistochemistry (IHC) in the primary diagnosis of oral diseases in one of the main services of oral pathology in the State of São Paulo, Brazil, and to identify the most common antibodies used, and recommend diagnostic algorithms based on our experience with challenging lesions. A total of 1698 IHC stains were performed in 401 cases from a total of 28,804 cases received from public dental clinics and private dental practitioners within a period of 13 years, representing a frequency of 1.4% of IHC solicitations. Among these, 112 (28%) were mandatory to reach a final diagnosis and 255 (63.6%) were confirmative. In 34 (8.4%) cases, it was not possible to reach a conclusive/final diagnosis, even with IHC. Regarding the nature of the lesions, 210 (52.3%) were benign, 163 (40.6%) were malignant tumors, 13 (3.2%) were reactive, 10 (2.5%) were premalignant, and 5 (1.2%) were lesions of uncertain malignancy. Small amount of tissue of some incisional biopsies, overlapping features of spindle cell lesions (epithelial, neural, melanocytic, smooth muscle, endothelial, and fibroblastic/myofibroblastic cell differentiation), and overlapping features of salivary gland lesions were the most frequent challenges in which IHC stains were requested. Spindle cell lesions were the most frequent (22%) among all cases that required IHC to reach a final diagnosis. The implementation of IHC for routine practice requires a wide range of markers, proper antibody selection, and knowledge to interpret the subjectivity of staining. The inherent limitation of incisional biopsies was pointed as a reason to inconclusive diagnosis, despite a wide range of antibodies that our laboratory displays.

Background Lymphomas in the oral and oropharyngeal regions are relatively uncommon, and their diagnosis is challenging and complex due to the myriad histopathological subtypes. Herein, we report a large series of oral and oropharyngeal lymphomas and compare our data with the currently available literature. Methods All cases diagnosed as lymphomas affecting the oral and oropharyngeal regions were retrospectively retrieved from seven Brazilian institutions. Clinicodemographic data and histopathological features were evaluated and described, while a comprehensive literature review was undertaken in order to compare our findings. Results A total of 304 cases of oral and oropharyngeal lymphomas were obtained, mostly affecting individuals aged 60-69 years (n = 68) with a mean age at diagnosis of 54.2 ± 20.1 years. Males and females were equally affected. Mature B-cell neoplasms (87.2%) were the most common group, followed by mature T- and NK-cell neoplasms (11.2%) and precursor lymphoid neoplasms (1.6%). The most frequent subtypes in each group were diffuse large B-cell lymphomas, not otherwise specified (n = 99), extranodal NK/T-cell lymphomas, nasal type (n = 12), and B-lymphoblastic leukaemia/lymphomas, not otherwise specified (n = 4). The most commonly involved sites were the palate (26.3%), mandible (13%), and maxilla (10.5%). Conclusion Diffuse large B-cell lymphoma, not otherwise specified, remains the most common subtype of lymphomas in the oral and oropharyngeal region. Older patients are the most affected, with no gender predilection and the palate and jaw are usually affected.

Background Hydroa vacciniforme-like lymphoproliferative disorder (HVLPD) is a chronic Epstein-Barr virus (EBV)-positive lymphoproliferative disease which may either present as an indolent condition or progress to a systemic T-cell lymphoma. Methods All HVLPD diagnosed over a 10-year period were retrieved and clinical data regarding sex, age, oral and systemic manifestations, and clinical follow-up were obtained. Immunohistochemistry was done in order to characterize the lymphoid cells and in situ hybridization was used to demonstrate the presence of EBV. Results Eleven cases were included, with a male predominance and a mean age of 25.1 years. Buccal mucosa and the lips were the most affected oral sites, appearing as painful ulcers. All patients exhibited facial oedema, usually affecting the lips, nose, and periorbital region. The clinical course was gradual but progressive, with four patients having fever and 3 showing lymphadenopathies. All cases showed a moderate to severe lymphocytic infiltrate with angiotropism, angiocentricity and epidermotropism. Two cases affecting the lip skin exhibited a periappendageal lymphocytic infiltrate. Few large pleomorphic cells were found, surrounded by smaller and medium-sized lymphoid cells, as well as reactive plasma cells, macrophages, neutrophils, and eosinophils. All lesions exhibited a cytotoxic T cell (CD8 +) phenotype with a variable proliferative index. All cases were associated with EBV and all patients died due to complications of the disease. Conclusions HVLPD is a rare disease that may show oral involvement with a cytotoxic T-cell phenotype, and is strongly associated with EBV. As shown in this series, HVLPD may show aggressive clinical behaviour.

Background Burkitt lymphoma (BL) is an aggressive B-cell lymphoma with three variants (endemic, sporadic, and immunodeficiency-associated), presenting with specific epidemiological and clinical features. Burkitt lymphoma affects the head and neck region (BLHN) in approximately 10% of cases. The aim of this study was to undertake a comparative analysis of the clinicopathologic and immunohistochemical (IHC) features of BLHN diagnosed in patients from Africa, Guatemala, and Brazil. Methods Cases diagnosed as BLHN were collected from the files of six oral pathology laboratory services (Brazil, South Africa, and Guatemala), and one Brazilian pediatric oncology hospital from 1986 to 2020. Clinicopathological and IHC data, and Epstein-Barr virus (EBV) status by in situ hybridization data for each case were reviewed and described. Results Of the 52 cases, BLHN was predominant in pediatric patients [43 (82.69%)] and males [43 (82.69%)], with a mean age of 11.26 ± 9.68 years (range, 1-39 years). Neck and cervical lymph nodes [14 (26.92%)], and involvement of both maxilla and mandible [8 (15.38%)], were the most common anatomical sites. Clinically, tumor/swelling [40 (31.25%)], cervical lymphadenopathy [14 (10.94%)], pain [12 (9.38%)], and bone destruction [12 (9.38%)] were frequent findings. All cases showed typical morphological characteristics of BL. IHC profiles included positivity for CD20 [52 (100%)], CD10 [38 (79.17%)], Bcl6 [29 (87.88%)], and c-Myc protein [18 (81.82%)]. EBV was positive in 18 cases (62.07%). The Ki-67 index ranged from 90-100%. Conclusion The clinicopathological and EBV profile of BLHN in South African, Guatemalan and Brazilian patients is similar.

Background Plasma cell neoplasms are characterized by the proliferation of a single clone of plasma cells with production of a monoclonal immunoglobulin. They can manifest as a single lesion (plasmacytoma) or as multiple lesions (multiple myeloma). Methods Paraffin-embedded tissue blocks of patients microscopically diagnosed with plasma cell neoplasms in the jaws were retrieved from five pathology files. Data including clinical, radiographic, microscopic and immunohistochemical findings, treatment employed, and follow-up status were retrieved from the pathology reports. Results Fifty-two cases were retrieved (mean age: 59.4 years) without sex predilection. The mandible was the most affected site (67.3%), usually associated with pain and/or paresthesia (53.8%). Lesions in other bones besides the jaws were reported for 24 patients (46.2%). Radiographically, tumors usually presented as poorly defined osteolytic lesions with unilocular or multilocular images, while microscopy revealed diffuse proliferation of neoplastic plasma cells with nuclear displacement and abundant eosinophilic cytoplasm. Two cases were classified as anaplastic, and amyloid deposits were found in two other cases. Immunohistochemistry was positive for plasma cell markers and negative for CD20 and CD3, and monoclonality for kappa light chain predominated. The overall survival rate after 5-years of follow-up was 26.6%. Conclusion Plasma cell neoplasms are aggressive tumors with a poor prognosis and involvement of the jaws may be the first complaint of the patient. Thus, oral pathologists, head and neck surgeons and dentists should be aware of their clinical, radiographic and microscopic manifestations.

Objective The aim of this study was to evaluate the influence of viral load and lymphocyte count on survival of patients who presented with human immunodeficiency virus (HIV)-associated oral Kaposi's sarcoma. Study Design Thirty-one cases (from January 2010 to December 2019) of oral Kaposi's sarcoma in patients with HIV from 2 oral pathology centers in Brazil were reviewed, considering clinical data and correlation of viral load and lymphocyte count with overall survival. Overall survival rates were estimated by a Kaplan-Meier analysis and compared using a log-rank test. The factors introduced stepwise into a Cox proportional hazard model to identify the independent predictors of survival. A P value Results Most of the patients were males (90.3%) with a mean age of 32.4 years (range, 19-58). Hard palate, soft palate, and tongue were the most affected sites. Treatment, viral load >999 copies/mL, CD4+ level ≤200 cells/mm3, CD4+/CD8+ level ≤0.39 cells/mm3, and CD4+ nadir level Conclusions Survival of patients affected by oral HIV-associated Kaposi's sarcoma is influenced by treatment, viral load, CD4+, CD4+/CD8+, and CD4+ nadir count.

Oncocytic lipoadenoma (OL) is a rare salivary gland tumor characterized by the presence of oncocytic cells and mature adipose tissue. To date, only 30 cases of OL have been reported in the English-language literature. We present 3 additional OL cases involving the parotid, including a synchronous presentation with paraganglioma of the right carotid bifurcation. Microscopically, both the OLs were composed of a mixed population of oncocytes and adipocytes in varying proportions surrounded by a thin, connective tissue fibrous capsule. Oncocytes were positive for pan-cytokeratins (CKs) AE1/AE3, epithelial membrane antigen, CK5, CK7, CK14, CK18, and CK19. Calponin, p63, alpha-smooth muscle actin, and carcinoembryonic antigen were negative. Vimentin and S-100 protein were positive only in adipose cells. Despite distinctive morphologic features, OL is often misdiagnosed, given its rarity. We hope to contribute to surgeons’ and pathologists’ awareness and knowledge regarding the existence of this tumor and provide adequate management through conservative surgical excision.

Objective The aim of this study was to report the clinicopathologic features of 62 cases of central odontogenic fibroma (COdF). Study Design Clinical and radiographic data were collected from the records of 13 oral pathology laboratories. All cases were microscopically reviewed, considering the current World Health Organization classification of tumors and were classified according to histopathologic features. Results There were 43 females and 19 males (average age 33.9 years; range 8–63 years). Clinically, COdF lesions appeared as asymptomatic swellings, occurring similarly in the maxilla (n = 33) and the mandible (n = 29); 9 cases exhibited palatal depression. Imaging revealed well-defined, interradicular unilocular (n = 27), and multilocular (n = 12) radiolucencies, with displacement of contiguous teeth (55%) and root resorption (46.4%). Microscopically, classic features of epithelial-rich (n = 33), amyloid (n = 10), associated giant cell lesion (n = 7), ossifying (n = 6), epithelial-poor (n = 3), and granular cell (n = 3) variants were seen. Langerhans cells were highlighted by CD1a staining in 17 cases. Most patients underwent conservative surgical treatments, with 1 patient experiencing recurrence. Conclusions To the best of our knowledge, this study represents the largest clinicopathologic study of COdF. Most cases appeared as locally aggressive lesions located in tooth-bearing areas in middle-aged women. Inactive-appearing odontogenic epithelium is usually observed within a fibrous/fibromyxoid stroma, occasionally exhibiting amyloid deposits, multinucleated giant cells, or granular cells.

The role of digital pathology in remote reporting has seen an increase during the COVID-19 pandemic. Recently, recommendations had been made regarding the urgent need of reorganizing head and neck cancer diagnostic services to provide a safe work environment for the staff. A total of 162 glass slides from 109 patients over a period of 5 weeks were included in this validation and were assessed by all pathologists in both analyses (digital and conventional) to allow intraobserver comparison. The intraobserver agreement between the digital method (DM) and conventional method (CM) was considered almost perfect (κ ranged from 0.85 to 0.98, with 95% CI, ranging from 0.81 to 1). The most significant and frequent disagreements within trainees encompassed epithelial dysplasia grading and differentiation among severe dysplasia (carcinoma in situ) and oral squamous cell carcinoma. The most frequent pitfall from DM was lag in screen mirroring. The lack of details of inflammatory cells and the need for a higher magnification to assess dysplasia were pointed in one case each. The COVID-19 crisis has accelerated and consolidated the use of online meeting tools, which would be a valuable resource even in the post-pandemic scenario. Adaptation in laboratory workflow, the advent of digital pathology and remote reporting can mitigate the impact of similar future disruptions to the oral and maxillofacial pathology laboratory workflow avoiding delays in diagnosis and report, to facilitate timely management of head and neck cancer patients. Graphical abstract.

Mucosal melanomas are aggressive tumors, rarely observed in the oral cavity. The diagnosis is based on the clinical and microscopical features. Often these tumors had variable amounts of melanin pigmentation. However, when melanin is absent, the tumors are denominated amelanotic, presenting a tendency to misdiagnosis and delayed treatment. The aim of this study was to describe the clinicopathologic features of a series of oral amelanotic melanomas (OAM). Records of all cases of OAM were retrospectively retrieved from oral pathology services from January 2002 to January 2019. Data regarding the clinical features, morphological aspects, immunohistochemical reactions, treatment, and follow-up status were collected. Eight cases of OAM were included, 6 in men and 2 in women (ratio of 3:1) ranging in age from 33 to 77 years (mean 53.6 years). Clinically, the tumors presented as masses or ulcerated swellings. The most common intraoral locations of the tumors were gingiva and palate. Cervical lymph node metastasis was detected in 3 patients at the first examination. All but one patient died from complications of the tumors after a mean follow-up period of 8.5 months. In conclusion, OAM is a very aggressive malignant tumor, and when melanin is absent, an immunohistochemical panel comprising S100, melan A, HMB45, and SOX10 should be performed.

OBJECTIVE In the present study, we aimed to investigate the prognostic value of RUNX1 expression in 76 patients with adenoid cystic carcinoma (ACC). MATERIALS AND METHODS All cases were arranged in tissue microarray blocks and submitted to immunohistochemistry against RUNX1. These results were statistically correlated with clinicopathologic features, including age, gender, tumour site, tumour size, lymph node status, AJCC clinical stage, distant metastasis, treatment, recurrences, follow-up, histologic pattern, vascular and neural invasion, all of which obtained from patient's medical records. RESULTS RUNX1 was expressed in the nuclei of tumour cells, with a mean of 18.1% of positivity. Nuclear RUNX1 expression was significantly associated with AJCC clinical stage (p

Aims The hallmarks of type 2 diabetes (T2D) are hyperglycaemia and insulin resistance. These factors, at the cellular level, are associated with mitochondrial dysfunction and increased glucose uptake. Such events are poorly explored in the context of the salivary glands. In this study, we present a series of eight cases of a distinct salivary gland lesion characterised by multiple oncocytic cysts, and we provide new pathological insights regarding its pathogenesis. Methods and results Seven patients (87.5%) had confirmed T2D, and obesity was identified in five (62.5%) patients. Clinically, the patients showed bilateral parotid gland swelling with recurrent episodes of pain and enlargement. Imaging examination revealed multiple cystic lesions in both parotid glands. Microscopically, the parotid glands showed multiple cysts of different sizes, lined by oncocytic epithelial cells. Intraluminally, strongly eosinophilic glass-like crystalloid material was observed. Immunohistochemical studies were performed, and the most notable finding was glucose transporter 1 (GLUT1) overexpression in the oncocytic cysts which is not observed in any other oncocytic lesion of patients without T2D. In addition, high expressions of mitochondrial antigen, fission 1 protein and mitofusin-2 were observed in the oncocytic epithelium of the cysts. Furthermore, most of the oncocytic cysts showed a pattern of cytokeratin expression consistent with striated ducts. Conclusions These results strongly suggest that T2D is associated with alterations in GLUT1 expression in the cells of striated ducts with mitochondrial dysfunction, causing a hyperplastic process characterised by multiple oncocytic cysts. For this lesion, the designation of 'diabetes-associated-bilateral multiple oncocytic cysts of the parotid gland' is proposed.

We present the frequency of cases of isolated odontogenic keratocysts submitted to microscopic examination at 10 Brazilian referral centres in Oral and Maxillofacial Pathology. In a retrospective (1953-2017) analysis, data on clinicoradiographic features and treatment of these lesions were collected and analysed descriptively. Among the 258,867 cases retrieved, 2,497 (0.96%) were isolated odontogenic keratocysts. In summary, an overview of individuals affected with isolated odontogenic keratocysts is reported herein. This lesion showed predilection for the posterior mandible of young adult men.

Objectives To evaluate clinical and pathologically cases of respiratory scleroma diagnosed in a 30-year period in Guatemala. Material and methods Fifty-one cases of respiratory scleroma diagnosed from 1988 to 2018 in a single pathology service in Guatemala were confirmed using Warthin-Starry staining. Immunohistochemical reactions against CD68, LCA, CD20, CD3, and CD138 were performed to illustrate the inflammatory infiltrate. Scanning electron microscopy (SEM) was performed to illustrate bacteria morphology. Results All 51 cases affected patients from poor areas of Guatemala, particularly women (66.7%), with a mean age of 31 years (range 7-66 years). Nose was affected in most cases (96.1%). Other sites involved included pharynx, larynx, palate, maxillary sinuses, and upper lip. Depending on the stage, the disease manifested as ulcerations, nasal deformities, or laryngeal stenosis. Nasal obstruction, epistaxis, dysphonia, fetid discharge, and pain were the main symptoms. Mikulicz cells (CD68+) in a plasma cell-rich inflammatory background (CD138+, CD20+, CD3+/-) were the typical microscopic presentation. In SEM, each macrophagic vacuole contained few to dozens of Klebsiella rhinoscleromatis diplobacilli. Treatment consisted of long-term trimethoprim and sulfamethoxazole, with adequate control of disease. Conclusion Respiratory scleroma is a rare infectious disease affecting the upper respiratory tract, in poor regions of the world, including Guatemala.

Background Hyalinizing clear cell carcinoma (HCCC) is an uncommon tumor that originates in the salivary glands. This neoplasia constitutes less than 1% of minor salivary gland tumors. Case summary A 67-year-old female visited the maxillofacial surgery department owing to a smooth, slightly yellowish protruding mass on the left side of the floor of the mouth, at the level of the molars; the tumor mass had a soft consistency on palpation and did not adhere to deep planes. The microscopical analysis of the excisional biopsy showed that the lesion was composed of sheets and cords of clear cells separated by thick eosinophilic bands of hyaline collagen. Normal glandular tissue was absent, periodic acid-Schiff with and without diastase stains, and immunohistochemical reactions were performed to confirm the diagnosis. This is the second case reported in the literature of HCCC arising in the floor of the mouth. Conclusion HCCC is a rare salivary gland tumor that has not been studied extensively. Its diagnosis is usually challenging, because clinically, it can be confused with a benign neoplasm.

Background The objective of this study investigated the distribution of immature dendritic cells (DCs), Langerhans cells and plasmacytoid DCs in oral submucous fibrosis (OSMF), OSMF associated with oral squamous cell carcinoma (OSMF-OSCC), oral leukoplakia (OL), and oral squamous cell carcinoma (OSCC). Material and Methods Fourteen cases of OSMF, 9 of OSMF-OSCC, 8 of OL¸ 45 of OSCC and 8 of normal epithelium were retrospectively retrieved and their diagnoses confirmed. Immunoreactions against CD1a, CD207 e CD303 were performed and the number of positive cells quantified. Results A significant decrease of CD1a+ was found in OSMF (p≤0.05), OSMF-OSCC (p ≤ 0.01), and OSCC (p ≤ 0.001) when compared to normal epithelium. For CD207+ the significance decrease was observed in OSMF-OSCC (p ≤ 0.05), and OSCC (p ≤ 0.01) when compared with normal epithelium, and in OSMF when compared with OL (p ≤ 0.05). There was no significant difference for CD303, but increased in CD303+ was observed in OSCC when compared with normal epithelium. Conclusions The decrease in the number of CD1a+ and CD207+ cells may be associate to the development of oral OSCC, and in OPMDs they might be indicators of malignant transformation. Key words:Premalignant lesions, oral submucous fibrosis, oral squamous cell carcinoma, immune response.

Objective The aim of this study was to determine the proteome of adenoid cystic carcinoma (AdCC) and polymorphous adenocarcinoma (PAc) and to identify a protein signature useful in distinguishing these two neoplasms. Study Design Ten cases of AdCC and 10 cases of PAc were microdissected for enrichment of neoplastic tissue. The samples were submitted to liquid chromatography–tandem mass spectrometry (LC-MS/MS), and the proteomics data were analyzed by using the MaxQuant software. LC-MS/MS spectra were searched against the Human UniProt database, and statistical analyses were performed with Perseus software. Bioinformatic analyses were performed by using discovery-based proteomic data on both tumors. Results LC-MS/MS analysis identified 1957 proteins. The tumors shared 1590 proteins, and 261 were exclusively identified in AdCC and 106 in PAc. Clustering analysis of the statistically significant proteins clearly separated AdCC from PAc. Protein expression 10 times higher in one group than in the other led to a signature of 16 proteins—6 upregulated in AdCC and 10 in PAc. A new clustering analysis showed reverse regulation and also differentiated both tumors. Conclusions Global proteomics may be useful in discriminating these two malignant salivary neoplasms that frequently show clinical and microscopic overlaps, but additional validation studies are still necessary to determine the diagnostic potential of the protein signature obtained.

OBJECTIVES The aim of this study was to investigate the prevalence of oral sarcomas from geographic regions of Brazil. MATERIALS AND METHODS A cross-sectional study was conducted on biopsies obtained from January 2007 to December 2016 at twelve Brazilian oral and maxillofacial pathology centres. Gender, age, evolution time, clinical aspects, tumour location, tumour size at diagnosis, radiographic aspects and histopathological diagnosis were evaluated. Data were analysed using descriptive statistical methods. RESULTS From 176,537, a total of 200 (0.11%) oral sarcomas were reported, and the most prevalent were osteosarcomas (74 cases; 37%) and Kaposi's sarcomas (52 cases; 26%). Males were more affected than females at a mean age of 32.2 years old (range of 3-87 years). The most common symptoms were swelling¸ localised pain and bleeding at a mean evolution time of 5.14 months (range

Mammaglobin is expressed in breast and salivary gland secretory carcinomas; however, its expression in salivary duct carcinomas (SDCs) still not well established. Therefore, the aim of this study was to investigate the presence and distribution of mammaglobin immunoexpression in SDC ex-PA in different phases of the adenoma to carcinoma sequence evaluating its possible involvement in carcinogenesis and tumor progression, as well as to determine its expression in SDC de novo. Mammaglobin immunohistochemistry was performed in 84 SG tumors, including 41 pleomorphic adenomas (PA) without malignant transformation, 13 intracapsular SDC ex-PA, 5 frankly invasive SDC ex-PA, 25 SDC de novo and 10 secretory carcinomas. The reactions were qualitatively analyzed and digitally scored. Positive immunostaining for mammaglobin was observed in 37 out of 84 SG tumors evaluated (44.1%), but strong staining was consistently seen only in secretory carcinomas, SDC de novo and frankly invasive SDC ex-PA, while it was weaker in intracapsular SDC ex-PA and PA. In PA, mammaglobin expression was significantly associated with recurrence. This study has confirmed that the mammaglobin is commonly expressed in SDC de novo and secretory carcinomas. Its expression was higher in SDC ex-PA than in PA, suggesting that mammaglobin may play a role in its malignant transformation.

Diffuse cutaneous leishmaniasis is a rare chronic infectious disease, associated with Leishmania mexicana and L. amazonensis, presenting as multiple non-ulcerative painless nodules, with a tendency to relapse soon after treatment. We report a case of a 56-year-old Mexican woman exhibiting nodular lesions, plaques, crusts and scars involving the whole body. A solitary nodule was present at the junction between hard and soft palates. Diffuse cutaneous leishmaniasis is a disfiguring disease resulting in severe scarring if untreated.

Lymphomas of the oral cavity are rare and the most frequent type is diffuse large B-cell lymphoma (DLBCL). Epstein-Barr virus (EBV) is known to be associated with the development of different lymphomas. In 2008, the World Health Organization provisionally included the EBV-positive DLBCL of the elderly in the classification of hematopoietic and lymphoid tumors as a lymphoma occurring in older individuals without any known immunodeficiency. However, it has since been recognized that this entity may occur in younger individuals and present similar clinical parameters in both age groups. As a result, the 2017 revision has declined the term elderly and modified it to EBV-positive DLBCL, not otherwise specified (NOS). In this report, we describe a rare case of EBV-positive DLBCL, NOS, presenting as a painless swelling in the oral cavity. This entity shows a more aggressive clinical course than EBV-negative DLBCL, and other lymphoproliferative disorders should be considered in the differential diagnosis.

Background Head and neck mucosal melanomas (MMs) are rare tumors with adverse outcomes and poorer prognoses than their more common cutaneous counterparts (cutaneous melanomas-CMs). Few studies have compared the expression of mitochondrial dynamic markers in these tumors. This study aimed to assess the correlations of mitochondrial markers with melanoma progression and their potential as predictors of lymph node involvement and distant metastasis. Methods Immunohistochemistry against anti-mitochondrial (AMT), dynamin-related protein 1 (DRP1), mitochondrial fission protein 1 (FIS1), mitofusin-1 (MFN1), and mitofusin-2 (MFN2) antibodies was performed in 112 cases of head and neck CM and MM. A Cox regression multivariate model was used to assess the correlation of AMT, FIS1, and MFN2 expressions considering the risk for nodal and distant metastasis. Results All markers studied presented higher staining in tumor cells than normal adjacent tissues. Higher mitochondrial content was observed in MM than in CM, and it was significantly associated with nodal metastasis in oral melanomas. Both FIS1 and DRP1 expressions were related to advanced Clark's levels in CM, and they were overexpressed in oral melanomas. Moreover, increased immunoexpression of MFN2 was significantly associated with a higher risk of metastasis in CM, and it was also overexpressed in sinonasal melanomas. Conclusions Our results suggest that mitochondrial fission and fusion processes can play an important role during multiple stages of tumorigenesis and the development of nodal and distant metastasis in cutaneous and mucosal melanomas.

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL-NT) is a lymphoid malignancy that mainly affects the nasopharynx and is associated with the Epstein-Barr virus (EBV). Increased incidence is seen in some Latin American and Asian countries. In this study, we describe a case series of 86 Guatemalan patients with ENKTCL-NT from a single diagnostic head and neck center. We emphasize the distinctive clinical, microscopic, and immunohistochemical (IHC) features, as well as EBV positivity by in situ hybridization (ISH). Most of the patients (90.6%) were of Mayan descent and low socioeconomic status (SES). Males were more often affected than females, comprising 68.3% of cases. Patient age ranged from 8 to 71, with a mean of 34.7 years. All cases arose in the upper aerodigestive tract and mainly presented as a rapidly progressive, necrotizing midfacial process affecting the nasal, nasopharyngeal, sinonasal, palatal, and oropharyngeal structures. Microscopically, ENKTCL-NT showed a diffuse polymorphic and atypical lymphoid infiltrate. Angiocentric and angiodestructive growth patterns were present with associated necrosis. Peripheral hyaline necrosis of blood vessels was a histologic hallmark. The ISH and IHC profiles included positivity of EBV, LCA, CD3, CD45RO, CD30 (focal in 39.2%), granzyme-B, TIA-1, perforin (in 82.3%), and CD56 (in 83.7%). CD20 was negative, and the Ki-67 index ranged from 70 to 90%. In Guatemala, this lymphoma is strongly associated with people of low SES and indigenous ethnicity. When affected, the palatal mucosa provides the best site to obtain a representative biopsy. Since ENKTCL-NT is highly aggressive, it is extremely important to recognize the spectrum of clinical presentations and microscopic features in order to avoid misdiagnosis and treatment delay.

Background The diagnosis of oral and maxillofacial mature T/NK-cell neoplasms is challenging because of their rarity, morphological heterogeneity and complex immunophenotype, with scarce available data describing their clinical and microscopic aspects. Therefore, in this study we investigated a series of mature T/NK-cell neoplasms affecting this anatomical region and provided an updated literature review. Methods Cases diagnosed as mature T/NK cell lymphomas affecting the oral and maxillofacial region were retrospectively retrieved from six pathology files and their diagnoses were confirmed using haematoxylin and eosin-stained slides, immunohistochemical reactions and in situ hybridization for Epstein-Barr virus (EBV) detection. Patients' clinical data were collected from their pathology forms. Results A total of 22 cases were included in this study. Eleven (50%) consisted of extranodal NK/T-cell lymphomas, nasal type; eight (36.4%) were peripheral T-cell lymphomas, NOS; two (9.1%) were adult T-cell leukaemia/lymphomas, and one (4.5%) was an ALK-positive anaplastic large cell lymphoma. Overall, males predominated, with a mean age of 55.7 years. The palate was the most affected site (50%), and tumours usually presented as destructive and painful ulcers. EBV was present in all cases of extranodal NK/T cell lymphoma nasal type, but was absent in the other subtypes. Conclusion Among mature T/NK-cell lymphomas of the oral and maxillofacial region, extranodal NK/T cell lymphoma, nasal type and peripheral T-cell lymphoma, NOS predominated. Older men were the most affected patients, and this heterogenous group of neoplasms has a very aggressive clinical behaviour.

This report describes a case of an adult rhabdomyoma (ARM) occurring in the oral cavity. A 47-year-old man was referred for the diagnosis of a painless, well-circumscribed, submucous nodule located on the floor of the mouth, measuring approximately 6.0 cm in length. Computed tomography revealed a well-defined, solid, and hypodense mass. A benign salivary gland or mesenchymal tumor were the main diagnostic hypotheses. Under local anesthesia, the patient underwent surgical excision. Microscopically, the tumor comprised large polygonal well-defined cells with abundant, eosinophilic granular cytoplasm with cross striations. No atypia or mitosis was observed. The cells were positive for muscle-specific actin, desmin, and sarcomeric alpha-actin. Based on these features, a diagnosis of ARM was established. No recurrence was observed after 48 months. Although rare, ARM should be considered in the differential diagnosis of oral submucosal nodules, especially those located on the floor of the mouth.

Drug-induced sarcoidosis-like reaction (DISR) is a condition almost indistinguishable from sarcoidosis, both clinically and microscopically, consisting of granulomatous tissue reaction associated with a specific therapy. Commonly affected sites are the lungs, hilar lymph nodes, and skin. This report aimed to describe a very uncommon case of DISR with an unique involvement of the oral cavity. A 63-year-old female with a history of rheumatoid arthritis, who was treated with a TNF-α antagonist (adalimumab), presented multiple ulcerative nodules on the hard palate. Laboratory tests and imaging studies failed to show any other alterations. The biopsy specimen demonstrated multiple noncaseating granulomas. Histochemical reactions were negative for acid-fast bacilli and fungi, and immunohistochemical assessment highlighted the presence of normal lymphocytes and histiocytes. With the diagnosis of DISR, adalimumab was discontinued, and complete clinical resolution of the lesions was achieved after 14 months. Although uncommon, DISR should be considered in differential diagnoses of oral granulomatous reactions, especially in cases where the patient is being treated with TNF-α antagonists.

Kaposiform hemangioendothelioma is a rare neoplasm with intermediate malignant behavior, mainly affecting infants and children. Involvement head and neck is uncommon, and there are only four cases reported in the oral cavity and oropharynx. Microscopically, it is characterized by a vascular proliferation permeated by spindle-to-ovoid cells resembling Kaposi sarcoma. Immunohistochemically, the tumor is positive for CD31, CD34 and negative for D2-40. Herein we present a rare case of intraoral Kaposiform hemangioendothelioma in a 10-year-old boy.

Fatty acid synthase (FASN) expression is closely related to cancer progression, in particular, tumor aggressiveness and poor prognosis. This study aimed to analyse the expression of FASN in carcinomas of the salivary glands and correlate it with Ki-67 expression. We analysed by immunohistochemistry the expression of FASN and Ki‐67 on tissue sections from 7 cases of adenocarcinoma, not otherwise specified (AdNOS), 6 cases of polymorphous adenocarcinoma (PAC), 16 cases of acinic cell carcinoma (AcCC), 19 cases of adenoid cystic carcinoma (AdCC), 15 cases of epithelial-myoepithelial carcinoma (EMC); 10 cases of secretory carcinoma (SC), 13 cases of mucoepidermoid carcinoma (MEC), 10 cases of salivary duct carcinoma (SDC) and 7 cases of myoepithelial carcinoma (MC). These carcinomas were classified into aggressive and indolent regarding their biological behaviour. Additionally, MEC and AdCC were also classified according to the histological grade. High expression of FASN was found in SDC (100%), SC (100%), AcCC (68.7%) and AdNOS (57.2%). No association was found between FASN and Ki-67 expression. Aggressive carcinomas showed a higher rate of Ki-67 proliferation (p

OBJECTIVE: To report the clinicopathologic features of acquired oral syphilis cases in South American countries. MATERIALS AND METHODS: Clinical data were retrospectively collected from the records of 18 oral diagnostic services in Argentina, Brazil, Chile, Colombia, Venezuela, Uruguay, and Peru. Serologies of nontreponemal and treponemal tests were used for diagnosis. RESULTS: The series comprised 339 cases of acquired oral syphilis. Secondary syphilis ranked as the most common stage (86.7%). Lesions were more frequent among males (58.0%) and young adults with a mean age of 33.3 years. Individuals aged 20-29 years were most affected (35.3%). The most commonly involved sites were the tongue (31.6%), lip/labial commissure (25.1%), and hard/soft palate (20.4%). Clinically, acquired oral syphilis usually presented as mucous patches (28.4%), papules (25.7%), and ulcers (18.1%). Skin manifestations occurred in 67.7% of individuals, while lymphadenopathy and fever were observed in 61.3% and 11.6% of all subjects, respectively. Most patients were treated with the benzathine penicillin G antibiotic. CONCLUSION: This report validates the spread of acquired oral syphilis infection among young adults in South America. Our directives include accessible diagnostic tools for proper disease screening, surveillance, and counselling of affected individuals, especially in low- and middle-income countries

Oral mucosal melanoma (OMM) is a rare and aggresive melanocytic malignant neoplasm, with incidence lower that 0.01 cases per 100.000 person-year and a worse prognosis than cutaneous melanoma. Oral melanocytic nevus (OMN) is a rare benign oral neoplasm, whose malignant transformation to OMM is debatable. The genetic basis of both lesions has been poorly explored and OMM is studied together with other mucosal melanomas as a group, despite being a separate entity....

Made available in DSpace on 2022-05-01T06:02:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 The oral lymphoepithelial cyst (OLC) is an uncommon lesion whose pathogenesis remains poorly understood. The aim of this study was to report the clinicopathologic features of the OLCs and to verify a possible association between OLCs and subgemmal neurogenous plaque (SNP) in the posterior lateral region of the tongue. A retrospective descriptive cross-sectional study was carried out. A total of 106,282 biopsy records of oral and maxillofacial lesions from six oral pathology services in Brazil were analyzed. All cases of OLCs were reviewed, and clinical and histopathological data were collected. Immunohistochemical reactions for S-100 protein were performed to confirm the diagnosis of SNP. Among all lesions, there were 132 (0.11%) cases of OLCs. The series comprised 83 females (62.9%) and 49 males (37.1%), with a 1.7:1 female-to-male ratio and a mean age of 45.8 ± 17.7 years. Most cases involved the tongue (n = 80; 62.0%) and presented clinically as asymptomatic papules or nodules with a yellow or whitish color. Microscopically, most of the cysts were entirely lined by parakeratinized stratified epithelium (n = 89; 67.4%) and filled with desquamated cells, keratin debris, amorphous eosinophilic material, and inflammatory cells in varying amounts. Connection with the epithelium of oral mucosa was observed in 18 cases (13.6%). SNP was found in 9/80 (11.2%) cases involving the tongue. The clinical and demographic features of OLCs were similar to those described in previous studies. Overall, this lesion has a predilection for the posterior region of the tongue of female adults. Clinicians must include the OLC in the differential diagnosis of yellow/white papules and nodules of the oral cavity. Department of Oral Diagnosis Piracicaba Dental School University of Campinas (UNICAMP) Department of Bioscience and Oral Diagnosis Institute of Science and Technology São Paulo State University (UNESP) School of Dentistry University of Fortaleza (UNIFOR) Department of Oral Diagnosis and Pathology School of Dentistry Federal University of Rio de Janeiro (UFRJ) School of Dentistry State University of Rio de Janeiro (UERJ) Oral Pathology Section Department of Oral Diagnosis Piracicaba Dental School University of Campinas (UNICAMP), Av. Limeira 901, P.O. Box 52 Department of Bioscience and Oral Diagnosis Institute of Science and Technology São Paulo State University (UNESP)

Ossifying fibromyxoid tumor (OFMT) is a rare mesenchymal soft tissue benign neoplasm with an uncertain line of differentiation, which arises most frequently in extremities. The head and neck region involvement is uncommon, with only ten intraoral cases published in the English-language literature. One additional case of OFMT is reported here, including a literature review of intraoral reported cases. A 45-year-old female patient presented a painless nodule involving the buccal mucosa of approximately two years duration, measuring nearly 1.3 cm in maximum diameter. The main histopathological features include ovoid to round cells embedded in a fibromyxoid matrix with a perpheral shell of lamellar bone. Immunohistochemically, the tumor showed immunoreactivity for vimentin and S100. No recurrence has been detected after 7 years of follow-up.

Salivary gland tumors (SGT) represent an uncommon heterogeneous group of tumors with complex clinical and pathological characteristics. The prevalence of these lesions varies between studies but has been estimated between 3 and 6% of all tumors in the head and neck region. The present study aimed to evaluate the distribution and demographic findings of salivary gland tumors diagnosed in an oral pathology service in Mexico. A retrospective descriptive cross-sectional study was performed. A total of 164 cases of SGT from a private oral pathology service were diagnosed between 2000 and 2019 in Mexico City. All cases were reviewed histologically, and demographic data and histopathological diagnoses were collected. A total of 110 (67.1%) tumors were benign, and 54 (32.9%) were malignant. The majority of patients were female (n = 100, 61.0%) with an overall female:male ratio of 1.6:1. The minor salivary glands were affected more than the major salivary glands (68.9% vs. 25.6%). The palate (n = 67, 40.9%) was the most commonly affected site, followed by the parotid gland (n = 37, 22.6%), lips (n = 16, 9.8%), and buccal mucosa (n = 14, 8.5%). Pleomorphic adenoma (n = 88; 80.0%) and mucoepidermoid carcinoma (n = 16, 29.6%) were the most frequent benign and malignant tumors, respectively. The general features of SGT from the studied Mexican population shared some similarities and differences compared to previously reported series from various parts of the world.

Carney complex (CNC) is a rare, autosomal dominant multiple neoplasia syndrome. Although cutaneous myxomas commonly occur in CNC patients, intraoral myxomas are extremely rare. We present a case of a palatal myxoma in a 21-year-old female patient with CNC, along with a review of the pertinent literature. She presented with a sessile nodule on the hard palate that microscopically showed a multilobulated and highly vascularized myxomatous tissue composed of loosely-arranged spindle, polygonal, and stellate cells, suggestive of myxoid neurofibroma. Six years after the oral lesion was removed, she presented with a growth hormone (GH)-producing pituitary adenoma, a cardiac myxoma, two cutaneous myxomas on the lower abdomen area, and one myxoma in the vaginal mucosa. Therefore, the final diagnosis of the palatal lesion was of a soft tissue myxoma related to CNC. The patient remains on close follow-up, with no recurrences of the palatal myxoma after 7 years.

During oral pathology daily practice, true amyloid may be identified in oral amyloidosis and several odontogenic tumors. However, histologic examination often reveals other oral and perioral diseases with similar eosinophilic, acellular, amorphous substances. These include extensive areas of collagenous sclerosis, fibrin deposition, elastic fiber degeneration, and dentinoid material, which may resemble amyloid under light microscopic examination. These materials are often termed "amyloid-like" due to their close histologic resemblance to true amyloid. The rarity of most of these conditions and their strong histologic similarity may hamper an accurate diagnosis. Definitive diagnosis of these lesions may require clinical correlation; laboratory evaluation; histochemical or immunohistochemical reactions; and, in some cases, genetic investigation. In this review, we describe the main clinicopathologic features of this group of diseases that may manifest in the oral and/or perioral regions and that have in common the presence of amyloid-like material deposition.

Background Sialolipoma is a rare histological variant of lipoma commonly misdiagnosed and composed of a proliferation of mature adipocytes with secondary entrapment of normal salivary gland tissue. The purpose of the present study is to report the clinicopathologic and immunohistochemical features of 10 new cases of sialolipomas in conjunction with a review of the literature. Methods A retrospective descriptive cross-sectional study was performed. A total of 54,190 biopsy records of oral and maxillofacial lesions from four oral and maxillofacial pathology services in Brazil were analysed. All cases of lipomas were reviewed, and clinical, demographic and histopathological data were collected of all cases compatible with sialolipomas. In addition, immunohistochemistry stains (AE1/AE3, CK7, 34βE12, S-100, HHF35, α-SMA and Ki-67) and a literature review based on a search of three electronic databases (PubMed, Web of Science and Scopus) were performed. Results Among all lipomas reviewed, there were 10 cases of sialolipomas. The series comprised of 7 females (70.0%) and 3 males (30.0%), with a mean age of 46.1 ± 21.5 years (range: 11-71 years) and a 2.3:1 female-to-male ratio. The lower lip (n = 3, 30.0%) and tongue (n = 2, 20.0%) were the most common locations, presenting clinically as a nodule of slow growth and normal colour. Conservative surgical excision was the treatment in all cases. No recurrence was observed. Conclusion Sialolipomas are a rare histological variant of lipoma, affecting the salivary glands, mainly in the parotid gland and palate of female adults. Pathologists must recognise sialolipomas to avoid misdiagnoses with other lipomatous tumours that can affect salivary glands.

Oral manifestations of tuberculosis (TB) are not so frequent, and the lesions may emerge in immunosuppressed patients as a secondary expression of pulmonary TB. The following two case reports focus on the clinical challenge of early diagnosis of painful ulcerative lesions in oral mucosa that occurred in two senior females, both human immunodeficiency virus negative patients, however receiving immunosuppressing medication. The patients did not present classic symptoms of TB. Nevertheless, based on different studies, extrapulmonary TB should still be considered as differential diagnosis for the oral mucosa lesions developed by these patients.

Validation studies of whole slide imaging (WSI) systems produce evidence regarding digital microscopy (DM). This systematic review aimed to provide information about the performance of WSI devices by evaluating intraobserver agreement reported in previously published studies as the best evidence to elucidate whether DM is reliable for primary diagnostic purposes. In addition, this review delineates the reasons for the occurrence of discordant diagnoses. Scopus, MEDLINE/PubMed, and Embase were searched electronically. A total of 13 articles were included. The total sample of 2145 had a majority of 695 (32.4%) cases from dermatopathology, followed by 200 (9.3%) cases from gastrointestinal pathology. Intraobserver agreements showed an excellent concordance, with values ranging from 87% to 98.3% (κ coefficient range 0.8-0.98). Ten studies (77%) reported a total of 128 disagreements. The remaining three studies (23%) did not report the exact number and nature of disagreements. Borderline/challenging cases were the most frequently reported reason for disagreements (53.8%). Six authors reported limitations of the equipment and/or limited image resolution as reasons for the discordant diagnoses. Within these articles, the reported pitfalls were as follows: difficulties in the identification of eosinophilic granular bodies in brain biopsies; eosinophils and nucleated red blood cells; and mitotic figures, nuclear details, and chromatin patterns in neuropathology specimens. The lack of image clarity was reported to be associated with difficulties in the identification of microorganisms (e.g., Candida albicans, Helicobacter pylori, and Giardia lamblia). However, authors stated that the intraobserver variances do not derive from technical limitations of WSI. A lack of clinical information was reported by four authors as a source for disagreements. Two studies (15.4%) reported poor quality of the biopsies, specifically small size of the biopsy material or inadequate routine laboratory processes as reasons for disagreements. One author (7.7%) indicated the lack of immunohistochemistry and special stains as a source for discordance. Furthermore, nine studies (69.2%) did not consider the performance of the digital method-limitations of the equipment, insufficient magnification/limited image resolution-as reasons for disagreements. To summarize the pitfalls of digital pathology practice and better address the root cause of the diagnostic discordance, we suggest a Categorization for Digital Pathology Discrepancies to be used in further validations studies. Among 99 discordances, only 37 (37.3%) had preferred diagnosis rendered by means of WSI. The risk of bias and applicability concerns were judged with the QUADAS-2. Two studies (15.4%) presented an unclear risk of bias in the sample selection domain and 2 (15.4%) presented a high risk of bias in the index test domain. Regarding applicability, all studies included were classified as a low concern in all domains. The included studies were optimally designed to validate WSI for general clinical use, providing evidence with confidence. In general, this systematic review showed a high concordance between diagnoses achieved by using WSI and conventional light microscope (CLM), summarizes difficulties related to specific findings of certain areas of pathology-including dermatopathology, pediatric pathology, neuropathology, and gastrointestinal pathology-and demonstrated that WSI can be used to render primary diagnoses in several subspecialties of human pathology.

Background The aim of this study was to describe the clinicopathological characteristics of 43 intraoral lipomas and classify them according to their microscopic variants. Material and Methods All the cases of intraoral lipomas diagnosed at an Oral Pathology service were selected for the study. Clinical data, such as age, gender, location, time of evolution, clinical presentation, clinical hypothesis of diagnosis, and treatment, were collected from the clinical files. Results Of the 43 cases analyzed, 24 (55.8%) occurred in women. The mean age was 77.4 years. The most affected site was the buccal mucosa (22 cases, 51.1%). The mean lesion size was 1.7 cm. Twenty-three cases (53.5%) were classified as simple lipoma, 14 (32.6%) as fibrolipoma, four (9.3%) as spindle cell/pleomorphic lipoma (SC/PL), one (2.3%) as lipoma of the salivary glands, and one (2.3%) as intramuscular lipoma. In one case of SC/PLs, lipoblasts were observed. No atypical lipoblasts or mitoses were noted. Lipoma was considered more often than other tumor histological subtypes among the clinical hypotheses of diagnosis when the final diagnosis was simple lipoma (p=0.01). Conclusions Intraoral lipomas present different clinical presentation depending on the histological subtype. In SC/PLs, lipoblasts with vacuolated cytoplasm may be found and the presence of mature adipocytes is essential for diagnosis. Key words:Lipoma, mouth, spindle cell lipoma, pleomorphic lipoma.