Histopathologic findings in ointment pseudo-cheilitis: An alert to dermatopathologists.

Ointment pseudo-cheilitis is a recently recognized distinctive type of self-induced cheilitis. Lesions consist of a variable amount of crusts adhered to the vermilion. These crusts consist of dried saliva and dead cells mixed with applied medications attached to the lip surface. Patients are typically severely anxious or depressed; the condition impacts quality of life. Ointment pseudo-cheilitis is frequently misdiagnosed as exfoliative cheilitis or cheilitis glandularis. Biopsy reports are often non-revealing because there are no established histopathological criteria for this disease, and clinicians usually do not formulate the correct diagnostic hypothesis. Here, we present the histopathological findings of four cases of ointment pseudo-cheilitis. The most consistent finding was the presence of laminated parakeratotic material detached from the epithelium in biopsies that are devoid of other significant diagnostic changes. This material at the lip surface possibly represents physiologic labial desquamation mixed with dried saliva and applied medication. With this report, we intend to alert dermatopathologists to the diagnosis of ointment pseudo-cheilitis if they receive biopsies from patients who present clinically exuberant labial lesions that show only minimal histopathological changes.

Oral lupus erythematosus: Immunohistochemical evaluation of CD1a, CD21, CD123, and langerin expression in dendritic cells.

BACKGROUND: Dendritic cells participate in the pathophysiology of lupus erythematosus (LE), which are studied in systemic and cutaneous forms; however, little is known about their oral manifestations. METHODS: The expressions of dendritic cell markers (including CD1a, CD21, CD123, and langerin) were investigated by immunohistochemistry technique. Sixty intraoral and lower lip LE lesions, and additional 10 control samples were collected from 2003 to 2019. They were topographically analyzed in the epithelium (EP), lamina propria (LP), epithelial junction (JUN), and deep perivascular (PV) areas. RESULTS: The expression of CD1a was decreased in the EP (p = 0.003) and increased in the deep PV area (p = 0.002). Langerin immunostaining showed no significant decrease in EP (p = 0.944); however, it increased in LP (p = 0.012) and JUN (p = 0.006). CD21 was expressed in only two specimens (EP, p = 0.012; LP, p < 0.001; deep PV area, p = 0.018). CD123 expression increased in all topographies (EP, p < 0.005; LP, p < 0.001, JUN, p < 0.001; deep PV, p < 0.001). The comparison between vermilion and intraoral mucosa LE lesions suggested that sun-exposed sites showed higher expression of CD123 (EP, p = 0.024; LP, p = 0.047; JUN, p = 0.001). CONCLUSIONS: CD1a, langerin, and CD123 expressions were detected coincidently surrounding the inflammatory infiltrate in oral LE, suggesting that these cells may play an important role in immune response. Interestingly, plasmacytoid dendritic cells showed increased CD123 expression in sun-exposed site lesions, which point out a possible function in their pathogenesis. Further studies are needed to confirm this hypothesis.

Three cases of oral mucosal tuberculosis in patients on tumour-necrosis-factor-α blockers.

We present three cases of oral mucosal lesions caused by Mycobacterium tuberculosis in patients treated with anti-tumour necrosis factor-α for psoriasis or rheumatoid arthritis. Diagnosis of oral mucosal tuberculosis was not easily established in any of the cases. A comparison between these cases and other previously described forms of oral mucosal tuberculosis is presented.

EMT in salivary gland tumors: the expression of microRNAs miR-155 and miR-200c is associated with clinical-pathological parameters.

BACKGROUND: Epithelial to mesenchymal transition promotes cell adhesion loss, enabling invasion and metastasis. MicroRNAs are a class of small non-codifying RNAs that regulate gene expression. OBJECTIVES: The aim of this study was to evaluate the expression of microRNAs that could regulate the expression of EMT factors in salivary gland tumors (SGTs). METHODS AND RESULTS: The expression of microRNAs miR-9, miR-34a, miR-101, miR-138, miR-155, and miR-200c-described in the literature to target EMT factors-was evaluated by Real-time RT-PCR (qPCR) in pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC) and adenoid cystic carcinoma (ACC) samples. Bioinformatics tools were applied to identify miR targets and immunohistochemistry was used to examine the expression of the proteins E-cadherin, Twist, ZEB-1, ß-Catenin, and c-Kit. Comparing miR expression among SGT types, we observed increased expression of miR-9, and miR-138 in PAs, and increased miR-155 expression in MECs. Low-grade MECs exhibited increased miR-155 expression (p = 0.032). MECs that generated lymph node metastases had increased miR-200c levels (p = 0.018). MECs tended to have decreased expression of EMT-related proteins when compared to the other SGT types (c-Kit p < 0.001, Twist p = 0.014, and ZEB p = 0.012). Notably, increased c-Kit expression was associated with the presence of perineural infiltration in ACC (p = 0.050). CONCLUSIONS: This study provides evidence of alterations in the expression of EMT-factors regulating miRs, especially of miR-9, miR-138, miR-155, and miR-200c. No significant relationships were found between the expression of these miRs and proteins associated with EMT in SGTs.

The Role of Reflectance Confocal Microscopy in the Evaluation of Pigmented Oral Lesions and Their Relationship With Histopathological Aspects.

ABSTRACT: Oral pigmentations are a heterogeneous group and can be the result of physiological activity of oral mucosal melanocytes, secondary to exogenous causes, associated with systemic or local diseases, or due to proliferative activity of melanocytes. Their diagnosis is critical because these lesions can be markers of internal diseases or, in the case of melanocytic proliferative processes, they may represent a malignant neoplasm. In the past decade, the use of reflectance confocal microscopy, a noninvasive imaging tool, has aided the analysis of such lesions, but the establishment of firm criteria in their evaluation is still lacking. This study evaluated a series of 19 cases of pigmented oral lesions and correlated the reflectance confocal microscopy findings with histopathological classical criteria. We found 13 cases of melanotic macule, 1 of them associated with Peutz-Jeghers syndrome and 2 with Laugier-Hunzinker syndrome; 1 melanocytic nevus; 2 lentigo maligna; 2 pigmented actinic cheilitis; and 1 case of postinflammatory pigmentation secondary to a lupus erythematosus oral discoid lesion. The main difference between benign and malignant lesions was the presence of atypical proliferation in lentigo maligna. Langerhans cells with thick dendritic processes, which may be present in other benign and inflammatory pigmentations is one of the main reasons for diagnostic pitfalls.

Extraordinary Case: Unique Presentation of an Aggressive Epstein-Barr Virus-Positive Mucocutaneous Ulcer.

ABSTRACT: Epstein-Barr virus-positive mucocutaneous ulcer is a recent and unusual type of lymphoproliferation, mostly associated with various forms of immunosuppression. In most cases, they regress spontaneously, but an increasing number of reports describe a spectral behavior of the lesion, which ranges from a simple ulcer with eosinophilia to aggressive ulcers. In these cases, Epstein-Barr virus-related lymphomas are the main differential diagnosis. We report a unique observation of this rare disease with mandibular involvement. Due to bone erosion, the patient was treated with 6 cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) with complete healing of the ulcer on clinical examination and PET-scan control.

Characteristics of aquaporin 1, 3, and 5 expression during early murine salivary gland development.

Aquaporins (AQPs) are essential to coordinate the transit of water and ions through the cell membrane. In salivary glands (SGs), AQPs have been associated with saliva formation, facilitating water absorption through the epithelium during the formation of hypotonic saliva, which is then secreted into the oral cavity. Different members of the AQP family have been suggested to play distinct roles during embryonic development, highlighted by their specific expression patterns. Here, we have investigated the expression patterns of AQP-1, AQP-3 and AQP-5 by immunofluorescence at key stages of salivary gland development, utilising cultured mouse embryonic submandibular (SMG) and sublingual (SLG) glands. The expression of AQPs was compared to a mitotic marker, phospho-histone 3 (PH3), a myoepithelial marker, smooth muscle actin (SMA), and a vascular marker, CD31. Qualitative analysis revealed that AQP-1 and AQP-3 were primarily expressed during the earlier phases of SG morphogenesis and were associated with cells undergoing mitotic processes (PH3-positive). AQP-5, in contrast, was not associated to mitotic figures, but was predominantly expressed during late stages of SG morphogenesis. Our results highlight that AQPs are expressed from early stages of SG morphogenesis and exhibit complimentary expression patterns that may contribute to the morphogenesis of salivary glands.

Orofacial Granulomatosis and Crohn Disease: Coincidence or Pattern? A Systematic Review.

BACKGROUND: To systematically review all cases of orofacial granulomatosis (OFG) and evaluate the association between OFG and Crohn disease (CD). SUMMARY: This review was conducted according to PRISMA guidelines and a search of the PubMed, MEDLINE, and Embase databases, and the Cochrane Library in March 2020, using keywords and MeSH terms associated with "orofacial granulomatosis," "Crohn disease," and their variants, with no language restrictions and across all age groups. All relevant articles were accessed in full text. Single case reports and articles on sarcoidosis, allergy, ulcerative colitis, and infectious diseases were excluded from the analysis. RESULTS: We retrieved 507 reports on OFG. The mean age at onset was 23.3 years (range 2-89 years). A total of 240 (47.3%) females and 267 (52.6%) males were included. CD was present in 93 children aged <16 years (68.3%) and in 43 adults (31.9%). In most cases, the OFG appeared before the CD. The most common clinical manifestations were intraoral mucosa abnormalities (n = 251; 49.5%), lower-lip swelling (n = 249; 49.1%), upper-lip swelling (n = 227; 44.7%), and gingivae (n = 193; 38.7%). Patients with concurrent CD were more likely to experience involvement of the buccal sulcus. Key Messages: OFG presents primarily as a solo entity. The OFG that was associated with CD was present in 93 children aged under 16 years (68.3%) and in 43 adults (31.9%). Childhood onset of OFG carries with it a higher risk of developing CD.

Oral Squamous Cell Carcinoma Bone Invasion: Possible Roles of E-Cadherin in Osteoclastogenesis and Bone Infiltration.

INTRODUCTION: Squamous cell carcinoma is the most common cancer of the oral cavity. When the tumor invades the bone tissue, the prognostic and survival rates decrease a lot, and the treatment becomes more aggressive, with several damages to the patient and health system. Many of the molecular mechanisms of bone invasion process are not understood yet, but it is already known that one of central processes of tumor evolution - adjacent tissues invasion and metastasis - is a large spectrum of phenotypic changes in epithelial cells to mesenchymal, in a process named as epithelial-mesenchymal transition (EMT). Loss of E-cadherin, an important epithelial cell adhesion protein, is a hallmark of this phenomenon. The objective of this retrospective study is to evaluate the expression of E-cadherin protein, comparing its distribution with clinical characteristics of the patients and possibly relation to EMT. METHODS: Sixty-two cases with respective clinical data were analyzed by comparing immunohistochemical, H and E staining, and clinical data, observing the tumor-bone interface (TBI) and the surrounding tumor that had no direct contact with the bone surface (ST). RESULTS: Forty cases were positive for E-cadherin (64%) with a heterogeneous pattern. Statistical analysis showed a significant difference between the presence of E-cadherin expression and tobacco smokers. Also, the equal or weaker protein expression in the ST than TBI is related to a worse overall survival. No statistically significant difference in other prognostic factors was observed. CONCLUSION: Our results suggest that the tumor cells that interact with the bone tissue could gain molecular changes, like partial EMT and osteoclastogenesis induction, which facilitate their migration and increase the bone resorption, resulting in a worse patient's prognosis.

From strawberry gingivitis to palatal perforation: The clinicopathological spectrum of oral mucosal lesions in granulomatosis with polyangiitis.

BACKGROUND: Reports of oral manifestations of granulomatosis with polyangiitis (GPA) usually refer to single-case reports; "strawberry gingivitis" has been increasingly reported. OBJECTIVE: To study the clinicopathological findings of four patients in which the diagnosis of GPA was suspected from the observation of their oral lesions and compare these to existent data. METHODS: Retrospective study of a case series. RESULTS: One patient presented typical "strawberry gingivitis" with localized disease and negative ANCA results. Two patients presented rapidly growing oral ulcers associated with systemic compromise and high ANCA levels. One patient presented with a chronic granulomatous lesion that leaded to palatal perforation. CONCLUSION: Oral manifestations of GPA may vary from rapidly evolving lesions in acutely ill patients to chronic and locally destructive lesions in slowing developing disease. These differences are also evident in the histopathological findings.

The histopathological spectrum of Melkersson-Rosenthal syndrome: Analysis of 47 cases.

BACKGROUND: Melkersson-Rosenthal syndrome (MRS) is a rare disease characterized by the triad of recurrent orofacial edema, relapsing facial paralysis and plicated tongue. Histopathological features of MRS have not been extensively analyzed. METHODS: This study investigated the histopathological aspects of oral lesions from 47 MRS patients. RESULTS: The most common biopsy site was the upper lip, followed by the lower lip, gingiva and palate. The most important findings were ill-defined and well-formed granulomas. Lymphoplasmacytic inflammatory infiltrate was seen in early and late stages of MRS. Edema, fibrosis, vasodilatation and congestion were the most common finding in the lamina propria. Gingival and palate exams also demonstrated granulomatous infiltrates. Regarding the evolution time of the disease, we demonstrated that, in initial phases, there is a lymphoplasmacytic inflammatory infiltrates, followed by a granulomatous infiltrate and, subsequently, fibrosis. CONCLUSION: Histopathological examination of oral lesions is helpful for the diagnosis of MRS; the absence of granulomatous inflammation does not exclude the diagnosis of syndrome. Clinical and histopathological analysis of the rare gingival and palate lesions is important, since all histopathological findings of the disease were detected in these sites.

Aquaporin 1, 3, and 5 Patterns in Salivary Gland Mucoepidermoid Carcinoma: Expression in Surgical Specimens and an In Vitro Pilot Study.

Salivary gland aquaporins (AQPs) are essential for the control of saliva production and maintenance of glandular structure. However, little is known of their role in salivary gland neoplasia. Salivary gland tumors comprise a heterogeneous group of lesions, featuring variable histological characteristics and diverse clinical behaviors. Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy. The aim of this study was to evaluate the expression of AQP1, AQP3, and AQP5 in 24 MEC samples by immunohistochemistry. AQP1 expression was observed in vascular endothelium throughout the tumor stroma. AQP3 was expressed in epidermoid and mucosal cells and AQP5 was expressed in mucosal cells of MEC. These proteins were expressed in the human MEC cell line UH-HMC-3A. Cellular ultrastructural aspects were analyzed by electron microscopy to certificate the tumor cell phenotype. In summary, our results show that, despite the fact that these molecules are important for salivary gland physiology, they may not play a distinct role in tumorigenesis in MEC. Additionally, the in vitro model may offer new possibilities to further investigate mechanisms of these molecules in tumor biology and their real significance in prognosis and possible target therapies.

Lichenoid sialadenitis in chronic graft versus host disease.

Chronic graft versus host disease (cGVHD) remains the principal long-term life-threatening complication in hematopoietic stem cell transplant recipients. We present a case of lichenoid sialadenitis in a 23-year-old-man with systemic cGVHD. The histological examination showed a lymphocytic inflammatory infiltrate adjacent to the salivary gland duct, similar to the histological aspects described in the typical manifestations of oral lichen planus and lichen planopilaris. This consists of a band-like inflammatory infiltrate not only targeting the cutaneous epithelium but also adnexal structures, such as hair follicles and salivary gland ducts. It is well described that the oral lesions in cGVHD share most of morphological and clinical manifestations with those described in oral lichen planus. The mechanisms of lichenoid salivary gland ducts destruction might be similar, although xerostomy appears to be specific to cGVHD, which may represent a clinical sign of massive salivary gland impairment related to ductal lichenoid destruction in patients with cGVHD.

Apoptosis and proliferation during human salivary gland development.

Human salivary gland (SG) branching morphogenesis is an intricate mechanism divided into stages, prebud, initial bud, pseudoglandular, canalicular, and terminal bud, to form the final lobular structure of the organ. The coordination of molecular cascades, including cell proliferation and apoptosis, are fundamental to this process. The intrinsic apoptosis pathway appears to be important in the early phases of ductal cavitation and luminisation; however, the role of the extrinsic apoptosis pathway has still to be determined. Questions remain as to whether the latter mechanism participates in the maintenance of the ductal lumen; therefore, the present study investigated the expression of proteins Prostate apoptosis response-4 (Par-4), Fas cell surface death receptor (Fas), Fas ligand (FasL), pleckstrin homology-like domain family A member 1 (PHLDA1), caspase-3, B-cell CLL/lymphoma 2 (Bcl-2), survivin, Ki-67, mucin 1 (MUC1), and secreted protein acidic and cysteine-rich (SPARC) during distinct phases of human SG development (50 specimens). This strategy aimed to draw an immunomorphological map of the proteins involved in apoptosis, cell proliferation, and tissue maturation during the SG branching morphogenesis process. Par-4 was positive at all stages except the pre-acinar phase. Fas and FasL were expressed in few cells. PHLDA1 was expressed in all phases but not in the terminal bud. Bcl-2 expression was mainly negative (expressed in few cells). Survivin showed a cytoplasmic expression pattern in the early phases of development, which changed to a predominantly nuclear expression during development into more differentiated structures. Ki-67 was expressed mainly at the pseudoglandular stage. MUC1 was positive in the pseudoglandular stage with a cytoplasmic pattern in regions of early luminal opening. Immunostaining for SPARC and caspase-3 was negative. Our results suggest that proteins associated with the regulation of extrinsic and intrinsic apoptosis contribute to apoptosis during specific phases of the early formation of SGs in humans.

Ointment Pseudo-Cheilitis: A Disease Distinct From Factitial Cheilitis. A Series of 13 Patients From São Paulo, Brazil.

BACKGROUND: The terms exfoliative cheilitis, factitial cheilitis, and morsicatio labiorum are used to describe self-inflicted lesions of the lip. OBJECTIVE: Here we report and analyze clinical, pathological, and therapeutic data on 13 patients with a form of factitial cheilitis that we believe should be considered a separate entity. RESULTS: Eight patients were male and 5 patients were female. All patients reported pain and presented with crusts consisting of dried saliva and topical medications adherent to the surface of the lips. These patients expressed great concern with their condition, and reported several previous, ineffective treatments. Simple reassurance only was not effective; saline compresses alleviated symptoms for a few patients. Most patients were lost to follow-up. Biopsies were not performed on all patients. CONCLUSION: This particular type of cheilitis artefacta has been previously described, but some features described herein are new and allow a specific approach: patient's behavior, the "protrusion sign," and possible improvement with antidepressants. For these cases, we propose the term ointment pseudo-cheilitis because it comprises the nature of the attached material and the lack of true inflammation. Further psychiatric characterization is a logical next step in further characterizing this difficult-to-treat condition.

Simple Bone Cyst Mimicking Stafne Bone Defect.

Stafne bone defects (SBDs) are asymptomatic lingual bony defects in mandible, which are usually detected as an incidental finding in plain radiographs. Similarly, simple bone cysts (SBCs) are most frequently found in posterior region of the mandible and also are asymptomatic. However, due to anatomical structures overlap in plain radiographs, there is a possibility of misdiagnosing SBD that often is diagnosed by presumptive diagnosis observed in plain radiograph. This report shows an unusual case that a SBC resembles a SBD.

A clinicopathological study of the oral lesions of Cowden disease.

BACKGROUND: Cowden disease is a multisystemic cancer predisposition disorder, inherited in an autosomal dominant pattern. Cutaneous and visceral lesions are either malignant tumours or are believed to represent hamartomatous growths. Mucocutaneous lesions are present on almost 100% of affected individuals. Nonetheless, some authors consider that the mucocutaneous manifestations of Cowden disease are, in reality, viral warts at distinct steps of evolution. There are only a few studies regarding the oral manifestations of Cowden disease. OBJECTIVES: To study the oral manifestations of Cowden disease in nine patients clinically and histopathologically. METHODS: The oral mucosal aspects of nine patients with clinical diagnosis of Cowden disease were photographed, and biopsies were taken from typical lesions. RESULTS: All biopsied lesions depicted histopathological aspects suggestive of viral warts at distinct steps of development: incipient, well established and in regression. CONCLUSION: Our findings seem to reinforce the poorly understood hypothesis that the mucocutaneous manifestations of Cowden disease are in reality viral warts. Additional studies are needed to explain why a syndrome caused by the mutation of a tumour suppression gene may cause propensity to warts.

Evaluation of the efficacy of photodynamic therapy for the treatment of actinic cheilitis.

INTRODUCTION: Actinic cheilitis (AC) is a lip intraepithelial neoplasia, whose cells present alterations similar to those presented by invasive squamous cell carcinomas (SCCs). OBJECTIVE: To conduct clinical and laboratory evaluation by histopathology and immunohistochemistry of the efficacy of actinic cheilitis treatment using photodynamic therapy (PDT) with methyl aminolevulinate (MAL) and noncoherent red light. MATERIALS AND METHODS: Patients with actinic cheilitis detected by histopathological examination were submitted to two sessions of photodynamic therapy with a two-week interval between them. They were examined immediately after the sessions, four, six, and twelve weeks after beginning treatment when a new biopsy was carried out. Clinical histopathological and immunohistochemical parameters were evaluated before and after treatment. RESULTS: Of the 23 patients who underwent biopsy, 16 completed two photodynamic therapy sessions and the material of one patient was insufficient for immunohistochemistry. Complete clinical response was achieved in 62.5% (10 of 16 patients) and 37.5% still remained with clinical evidence of AC. In spite of this, no case of cure by histopathological analysis was found. There was no significant statistical change among the values of Ki-67, survivin, and p53 observed before and after treatment. CONCLUSION: Photodynamic therapy, as carried out in this trial, was not an efficacious therapeutic option for treating patients with actinic cheilitis included in this sample.

The sonic hedgehog signaling pathway contributes to the development of salivary gland neoplasms regardless of perineural infiltration.

The pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (ACC) are common tumors arising from salivary glands whose histopathology is heterogeneous. The sonic hedgehog signaling pathway (Hh) and signal transducer and activator of transcription 3 (STAT3) play important roles in cell proliferation, favoring tumor growth. The aim of this investigation was to study components of the Hh pathway, as well as STAT3 in salivary gland neoplasms in an attempt to add information about the biological characteristics of these neoplasms. We used 9 cases of PA, 17 cases of ACC, and 20 cases of MEC. Using immunohistochemistry, SHH, GLI1, SUFU, HHIP, and STAT3 were investigated. For comparative purposes, MCM3 (cellular proliferation marker) was also included. In PA, there was high expression of cytoplasmic SHH and SUFU and low expression of STAT3 and MCM3. In the ACC, there was high expression of GLI1, HHIP, and STAT3 and low expression of SHH, SUFU, and MCM3. In the MEC, we observed high expression of SHH, GLI1, SUFU, and HHIP and low expression of STAT3 and MCM3. There was a statistically significant difference between SHH (p = 0.0064), STAT3 (p = 0.0003), and MCM3 (p = 0.0257) when all tumors were compared and a higher expression in parenchyma for all tumors when stroma and parenchyma were compared (p < 0.05). These findings suggests a possible role of Hh pathway in the development and maintenance of the cytoarchitectural pattern of PA, ACC, and MEC, as well as the participation of STAT3 in the development of ACC, irrespective perineural infiltration.

Expression of stem cell-regulating miRNAs in oral cavity and oropharynx squamous cell carcinoma.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common tumor worldwide and is histologically heterogeneous. Studies have demonstrated the presence of stem cell markers in HNSCC, and microRNAs (miRNAs) have emerged as powerful regulators of differentiation, controlling the self-renewal of stem cells. miRNAs are non-coding RNA molecules that regulate gene expression post-transcriptionally. Many miRNAs have been described as regulators of stem cells in different types of cancer. METHODS: We have analyzed the expression of let-7a, miR-34, miR-125b, miR-138, miR-145, miR-183, miR-200b, miR-203, and miR-205 by real-time RT-PCR (qPCR), in 35 oral cavity and oropharynx squamous cell carcinoma (SCC) samples and 10 non-neoplastic oral mucosa controls, to determine possible associations between the expression of these miRNAs and clinical and pathological features of these tumors. RESULTS: We observed downregulation of miR-200b and miR-203 in 60.0% and 71.4% of the samples, respectively. Upregulation of miR-138 and miR-183 was observed in 50.0% of the samples. Downregulation of let-7a was associated with perineural invasion. Upregulation of miR-138, miRNA-145, and miR-205 was associated with advanced tumor stages, vascular invasion, and lymph node metastasis, respectively. CONCLUSIONS: Our study provides evidence of the expression of miRNAs associated with stem cell regulation in oral cavity and oropharynx SCC and the association of these miRNAs with clinical and pathological features of these tumors.