Search

Proliferative verrucous leukoplakia (PVL) is an oral potentially malignant disorder associated with high risk of malignant transformation. Currently, there is no treatment available, and restrictive follow-up of patients is crucial for a better prognosis. Oral leukoplakia (OL) shares some clinical and microscopic features with PVL but exhibits different clinical manifestations and a lower rate of malignant transformation. This study aimed to investigate the proteomic profile of PVL in tissue and saliva samples to identify potential diagnostic biomarkers with therapeutic implications. Tissue and saliva samples obtained from patients with PVL were compared with those from patients with oral OL and controls. Label-free liquid chromatography with tandem mass spectrometry was employed, followed by qualitative and quantitative analyses, to identify differentially expressed proteins. Potential biomarkers were identified and further validated using immunohistochemistry. Staining intensity scan analyses were performed on tissue samples from patients with PVL, patients with OL, and controls from Brazil, Spain, and Finland. The study revealed differences in the immune system, cell cycle, DNA regulation, apoptosis pathways, and the whole proteome of PVL samples. In addition, liquid chromatography with tandem mass spectrometry analyses showed that calreticulin (CALR), receptor of activated protein C kinase 1 (RACK1), and 14-3-3 Tau-protein (YWHAQ) were highly expressed in PVL samples. Immunohistochemistry validation confirmed increased CARL expression in PVL compared with OL. Conversely, RACK1 and YWHA were highly expressed in oral potentially malignant disorder compared to the control group. Furthermore, significant differences in CALR and RACK1 expression were observed in the OL group when comparing samples with and without oral epithelial dysplasia, unlike the PVL. This research provides insights into the molecular mechanisms underlying these conditions and highlights potential targets for future diagnostic and therapeutic approaches., (Copyright © 2023 United States & Canadian Academy of Pathology. Published by Elsevier Inc. All rights reserved.)

This study aimed to evaluate the density of the dendritic cells (DCs) and macrophages in oral leukoplakia (OL) and proliferative verrucous leukoplakia (PVL) by immunohistochemical analysis. We analysed paraffined tissue samples of PVL ( n = 27), OL ( n = 20), and inflammatory fibrous hyperplasia ( n = 20) as the control group using the immunomarkers for DCs (CD1a, CD207, CD83, CD208 and CD123) and macrophages (CD68, CD163, FXIIIa and CD209). A quantitative analysis of positive cells in the epithelial and subepithelial areas was determined. Our results showed a reduction in CD208+ cells in the subepithelial area of the OL and PVL compared to the control. Additionally, we found a higher density of FXIIIa+ and CD163+ cells in the subepithelial area in PVL compared to the OL and control. Four-way MANOVA revealed a relationship between increased CD123+ cell density in the subepithelial area of "high-risk" samples regardless of disease. Macrophages provide the first line of defence against PVL antigens, suggesting a distinct pattern of innate immune system activation in PVL compared to OL, which may contribute to the complexity and the high rate of malignant transformation in the PVL.

Objectives: While unknown for oropharyngeal squamous cell carcinoma (OPSCC) and oral squamous cell carcinoma (OSCC), some studies assessing cervical carcinoma have shown that human papillomavirus (HPV) co-infection can be associated with its prognosis., Methods: Through in situ hybridization (HPV and Epstein-Barr virus [EBV] probes) and immunohistochemistry (p16 INK4a , cyclin D1, p53, and Ki-67 antibodies), 126 OPSCC and 109 OSCC samples were assessed., Results: All patients were EBV-negative. OPSCC (25%) showed a significant association with HPV compared to OSCC (11%). Almost all HPV-associated cases were p16 INK4a -positive. Regarding OPSCC and OSCC, 23 and 7 cases were positive for high-risk HPV (HRHPV) only, 6 and 3 cases for low-risk HPV (LRHPV) only, and 3 and 2 cases for HRHPV/LRHPV, respectively. HPV-associated carcinomas showed a significantly higher proliferative index than HPV-unassociated carcinomas. Both carcinomas showed a similar overall survival rate, which was not affected by the HPV status. However, when comparing HPV-associated subgroups, patients with HRHPV/LRHPV-associated carcinomas showed worse survival., Conclusion: LRHPV-associated and HRHPV/LRHPV-associated cases can also be detected when assessing OSCC and OPSCC. Further studies, especially in populations with a high prevalence of HPV-associated OPSCC, are necessary to understand the clinicopathological behavior of these neoplasm subgroups., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest in the present manuscript., (Copyright © 2021. Published by Elsevier B.V.)

Poor prognosis associated with the dysregulated expression of activin A in a number of malignancies has been related to with numerous aspects of tumorigenesis, including angiogenesis. The present study investigated the prognostic significance of activin A immunoexpression in blood vessels and cancer cells in a number of oral squamous cell carcinoma (OSCC) cases and applied in vitro strategies to determine the impact of activin A on angiogenesis. In a cohort of 95 patients with OSCC, immunoexpression of activin A in both blood vessels and tumor cells was quantified and the association with clinicopathological parameters and survival was analyzed. Effects of activin A on the tube formation, proliferation and migration of human umbilical vein endothelial cells (HUVECs) were evaluated in gain‑of‑function (treatment with recombinant activin A) or loss‑of‑function [treatment with activin A‑antagonist follistatin or by stable transfection with short hairpin RNA (shRNA) targeting activin A] conditions. Conditioned medium from an OSCC cell line with shRNA‑mediated depletion of activin A was also tested. The profile of pro‑ and anti‑angiogenic factors regulated by activin A was assessed with a human angiogenesis quantitative PCR (qPCR) array. Vascular endothelial growth factor A (VEGFA) and its major isoforms were evaluated by reverse transcription‑qPCR and ELISA. Activin A expression in blood vessels demonstrated an independent prognostic value in the multivariate analysis with a hazard ratio of 2.47 [95% confidence interval (CI), 1.30‑4.71; P=0.006) for disease‑specific survival and 2.09 (95% CI, 1.07‑4.08l: P=0.03) for disease‑free survival. Activin A significantly increased tubular formation of HUVECs concomitantly with an increase in proliferation. This effect was validated by reduced proliferation and tubular formation of HUVECs following inhibition of activin A by follistatin or shRNA, as well as by treatment of HUVECs with conditioned medium from activin A‑depleted OSCC cells. Activin A‑knockdown increased the migration of HUVECs. In addition, activin A stimulated the phosphorylation of SMAD2/3 and the expression and production of total VEGFA, significantly enhancing the expression of its pro‑angiogenic isoform 121. The present findings suggest that activin A is a predictor of the prognosis of patients with OSCC, and provide evidence that activin A, in an autocrine and paracrine manner, may contribute to OSCC angiogenesis through differential expression of the isoform 121 of VEGFA.

Background: M2 macrophages are often detected in oral squamous cell carcinoma (OSCC), which, influenced by hypoxic conditions, appear to have high angiogenesis-inducing capacity. However, the effects of immunosenescence on tumor-associated macrophages (TAMs) and angiogenesis in OSCC are unknown., Methods: Fifty-seven OSCCs were divided into 3 groups (I: <40 years [n = 17]; II: 40-65 years [n = 20]; III: >65 years [n = 20]). Immunohistochemistry for CD68 and CD163 (TAMs), and CD34 and D2-40 for microvessel density (MVD), microvessel area (MVA), and total vascular area (TVA) were performed., Results: All groups showed similar clinicopathological and immunohistochemical findings. Similar CD68 and CD163 expression, confirmed a M2 phenotype. MVD, MVA, and TVA were similar, however, with significant predominance of blood vessels. No significant correlation between macrophage and angiogenic markers was observed., Conclusions: A similar TAM and angiogenesis profile suggests the participation of other mechanisms, instead immunosenescence, in young and elderly OSCC patients., (© 2019 Wiley Periodicals, Inc.)

A 47-year-old man was referred for treatment of a painful lesion of 5 months' duration located on the left side of the maxilla. A small perforation in the buccal cortex was observed during the intraoral examination. Cone beam computed tomography (CBCT) showed an extensive, well-delimited radiolucent lesion extending from the alveolar ridge to the nasal cavity. An incisional biopsy was performed, and a cystic lesion consistent with an odontogenic keratocyst (OKC) was observed microscopically. The initial treatment option was decompression to be followed by enucleation. However, 3 months after decompression of the lesion, the patient returned because there was a significant increase in the size of the perforation. A destructive lytic lesion that involved the left side of the maxilla and crossed the midline was evident in the CBCT. The examination of a second incisional biopsy specimen showed epithelial neoplasia comprising islands and projections toward the surface. There was abundant keratin deposition, resulting in the formation of pearls and plugs. A diagnosis of primary intraosseous carcinoma arising from an OKC was confirmed, and the patient underwent a maxillectomy. After 1 year of follow-up, there were no signs of recurrence.

The low-fat and fat-free spindle cell lipomas (SCLs) are rare and often mistaken for other benign and malignant morphological mimics, because of the fact that the diagnosis relies on its non-lipogenic component analysis. Here, we report the clinicopathological features of two oral SCLs (low-fat and fat-free variants). Both lesions presented clinically as an asymptomatic nodule, which initially yielded diagnostic difficulties on the morphological analysis alone. One case was diagnosed as low-fat SCL on the lower lip in a 29-year-old man, and the other as fat-free SCL on the buccal mucosa in a 46-year-old man. In both cases, immunohistochemistry showed strong positivity for CD34 and, remarkably, retinoblastoma (Rb) protein was deficient. Mast cell (MC) tryptase and toluidine blue stain highlighted numerous MCs distributed throughout all tumor stroma. Alpha-SMA and desmin were negative. S100 evidenced scarce adipocytes only in the low-fat SCL case. Conservative surgical treatment was performed and no recurrence was noticed in about 2-year of follow-up in both cases. Because of the potential pitfalls, careful morphological analysis of the tumor stroma in the low-fat/fat-free SCL diagnosis, supported by immunohistochemistry (especially CD34, Rb and MC tryptase), is strongly recommended. To the best of our knowledge, these are the first and second cases reported of fat-free and low-fat SCL in the oral cavity., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Cellular neurothekeomas (CNs) are distinctive benign tumors of uncertain histogenesis, with predilection for the skin of the head and neck region. We describe the first case of multiple desmoplastic CNs (DCNs) affecting the oral cavity in a 9-year-old girl. Histopathologic evaluation showed a proliferation of spindle and epithelioid cells, forming nests and bundles, supported by exuberant fibrous stroma, as well as scattered multinucleated floret-like giant cells. The tumor cells were immunopositive for vimentin, CD63, CD56, whereas AE1/AE3, S100, CD34, α-SMA, GFAP, EMA, CD57 and NSE were negative. Ki-67 was <2%. Multiple DCNs should be considered in the differential diagnosis of oral nodular lesions.

Sjögren's syndrome (SS) is a systemic chronic autoimmune disorder affecting the lacrimal and salivary glands. SS may manifest as primary SS (pSS) or secondary SS (sSS), the latter occurring in the context of another autoimmune disorder. In both cases, the dry eyes and mouth affect the patient's quality of life. Late complications may include blindness, dental tissue destruction, oral candidiasis and lymphoma. This paper reports two cases of SS, each of them presenting unusual oral nodular lesion diagnosed as relapsed MALT lymphoma and mucocele. The importance of the diagnosis, treatment and management of the oral lesions by a dentist during the care of SS patients is emphasized, as the oral manifestations of SS may compromise the patient's quality of life.

Spindle cell lipoma (SCL) and pleomorphic lipoma constitute a spectrum of lipomatous lesions with distinctive clinicopathological features. Multiple variants of SCL have been reported including fibrous, plexiform, vascular, pseudoangiomatous, low-fat/fat-free, and myxoid changes. This paper describes an unusual patient with a 1-cm submucosal nodular lesion excised from the buccal mucosa of a 55-year-old woman with classic histopathological and immunohistochemical features of "low-fat" plexiform SCL with prominent myxoid stroma, which initially suggested a soft-tissue myxomatous lesion other than SCL. The current lesion exhibited microscopically few adipocytes supported by network-like myxoid proliferations with retraction artifacts from the surrounding stromal connective tissue. Immunohistochemistry was positive for vimentin, CD34, CD10, and S100, the latter only on adipocytes. The Ki-67 was <1%. Pan-cytokeratin (AE1/AE3), desmin, alpha-SMA, EMA, bcl-2, p53, and remarkably retinoblastoma protein (pRb) were negative. "Low-fat" plexiform SCL bear no significant prognostic significance, but this lesion may challenge the diagnosis even experienced pathologists.

Objective: The aim of this study was to analyze the immunohistochemical expression of Skp2 protein in 38 oral nevi and 11 primary oral melanomas., Study Design: Expression of this ubiquitin protein was evaluated by immunohistochemistry in 49 oral melanocytic lesions, including 38 intramucosal nevi and 11 primary oral melanomas. The labeling index (LI) was assessed considering the percentage of cells expressing nuclear positivity out of the total number of cells, counting 1000 cells per slide., Results: Skp2 protein was rarely expressed in intramucosal nevi, in contrast to oral melanomas, which showed high levels of this protein., Conclusion: These results indicate that Skp2 protein may play a role in the development and progression of oral melanomas, and it also could be useful as an immunohistochemical marker for differential diagnosis of oral benign and malignant melanocytic lesions.

Evaluation of cell cycle using antibodies against nuclear proteins involved in regulating DNA replication has gained special interest in the effort to predict biologic behavior of benign and malignant tumors. The aim of this study was to analyze the expression of minichromosome maintenance 2, Ki-67, and geminin in oral nevi and melanomas. Expression of these cell proliferation markers was evaluated by immunohistochemistry in 49 oral melanocytic lesions, including 38 intramucosal nevi and 11 primary oral melanomas. The labeling index of each proliferation marker was assessed considering the percentage of cells expressing nuclear positivity out of the total number of cells, counting 1000 cells per slide. Minichromosome maintenance 2, Ki-67, and geminin were rarely expressed in intramucosal nevi, in contrast to oral melanomas, which showed high levels of these cell proliferation markers, particularly minichromosome maintenance 2, indicating it is a more sensitive marker in primary oral melanomas than Ki-67 and geminin. These results indicate that these markers may be involved in the pathogenesis of oral melanomas and could be eventually useful as an additional diagnostic tool for differential diagnosis of oral benign and malignant melanocytic lesions., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The acquisition of abnormalities at G1/S is considered a crucial step in the genesis and progression of melanoma. The expression of cell cycle regulators has also been used in various neoplasms as an adjunct to diagnosis. The aim of this study was to compare the expression of p16, p21, p27 and cyclin D1 in oral nevi and melanomas. Expression of these cell cycle regulatory proteins was evaluated by immunohistochemistry in 51 oral melanocytic lesions, including 38 intramucosal nevi and 13 primary oral melanomas. p16 and p27 were highly expressed in intramucosal nevi, whereas p21 and cyclin D1 expression was higher in oral melanomas. The results indicate that p21 and cyclin D1 may be involved in the development of oral melanomas, and eventually they may be useful in the differential diagnoses of oral benign and malignant melanocytic lesions.

Objective: The aim of this study was to analyze the histopathological and immunohistochemical characteristics of 22 cases of primary oral melanomas (OM)., Study Design: Twenty two cases of primary oral melanoma were analyzed by description of their histopathological features and immunohistochemical study using the antibodies S-100, HMB-45, Melan-A and Ki-67., Results: The mean age was 58 years and 14 cases were female. The main affected sites were the hard palate, followed by the upper gingiva. Microscopically, 15 cases presented level III of invasion, 2 cases were amelanotic and 13 showed a mixed epithelioid and plasmacytoid or spindle cells composition. Some cases showed necrosis, perivascular and perineural invasion. S-100 and HMB-45 were positive in all cases, but 3 cases were negative for Melan-A. The proliferative index with Ki-67 was high, with labeling index ranging from 15.51% to 63% of positive cells., Conclusion: S-100 and HMB-45 are more frequently expressed than Melan-A in primary oral melanomas and these markers are helpful to confirm the diagnosis.

Giant cell angiofibroma is a well-circumscribed, normally encapsulated, distinctive orbital soft tissue tumor. However, it is now recognized that this lesion can also present in other locations, including the oral cavity. The morphological hallmark is a richly vascularized, patternless spindle cell proliferation containing pseudovascular spaces and floret-type multinucleate giant cells. CD34 immunoreactivity, although not specific, represents the only immunohistochemical finding of potential diagnostic value. We present a case of a 44-year-old male Caucasian patient complaining of painless solitary nodule arising on the right buccal mucosa, which was diagnosed as giant cell angiofibroma. To the best of our knowledge, this is the third case of oral giant cell angiofibroma reported in the English-language literature.

Oral melanoacanthoma (MA) is a rare, benign pigmented lesion, similar to cutaneous MA, characterized by hyperplasia of spinous keratinocytes and dendritic melanocytes. The pathogenesis of oral MA remains uncertain, although its clinical behavior is suggestive of a reactive origin. The most common intraoral sites are the buccal mucosa, lip, palate and gingiva. The average age of presentation is 28 years, mainly in blacks, with a strong female predilection. The oral melanotic macule (MM) is a small, well-circumscribed brown-to-black macule that occurs on the lips and mucous membranes. The etiology is not clear and it may represent a physiologic or reactive process. The average age of presentation is 43 years, with a female predilection. A biopsy is recommended to distinguish these lesions from each other and from other oral melanocytic lesions. We depict four cases each of oral MA and MM, affecting Caucasian and Latin American mestizo patients. The clinicopathological features of these cases reflect its ample spectrum, and to the best of our knowledge, it is the first example of oral MA affecting a Caucasian boy reported in the English literature. Therefore oral MA and MM should be considered in the differential diagnosis of pigmented lesions in the oral mucosa in these populations.