Biomimetics and the restoration of the endodontically treated tooth / Biomimética e a restauração do dente tratado endodonticamente

Although much progress has been obtained in terms of the Endodontic treatment, the literature shows that true success can be only achieved with adequate coronal seal to avoid bacterial contamination, and protect the tooth structure from fracture. There are many options available to the clinician to restore the endodontically treated tooth; however, there is not much evidence available on what alternative is better than another. This review will critically present the current knowledge on restorative choices, including posts and endocrowns, showing advantages and disadvantages of different treatment forms. With this knowledge, we will also introduce the concept of biomimetics to endodontically treated teeth, and how the nature of their remaining tooth structure can benefit from this approach. This concept entails the use of mechanisms and biologically produced materials to restore a tooth in a way that would mimic its natural structure, with the purpose of achieving better long-term prognosis (AU)

Embora tenha se obtido progresso em relação ao tratamento endodôntico, a literatura mostra que o sucesso real só pode ser atingido com o selamento coronal adequado, para evitar-se a contaminação bacteriana e proteger-se a estrutura dental de fraturas. Há muitas opções disponíveis para o clínico para a restauração do dente tratado endodonticamente; entretanto, não há muita evidência disponível sobre qual alternativa é melhor que a outra. Esta revisão apresentará criticamente o conhecimento atual sobre opções restauradoras, incluindo retentores intraradiculares e endocrowns, mostrando vantagens e desvantagens das diferentes formas de tratamento. Com esse conhecimento, também introduziremos o conceito de biomimética, uma vez que dentes tratados endodonticamente, devido a natureza de sua estrutura dental remanescente, podem se beneficiar desta abordagem. Esse conceito envolve o uso de mecanismos e materiais produzidos biologicamente para restaurar um dente de forma a imitar a estrutura natural, com o objetivo de alcançar melhor prognóstico de longo-prazo.(AU)

Screening methylation of DNA repair genes in the oral mucosa of chronic smokers.

OBJECTIVE: The aim of this study was to evaluate the epigenetic changes in the process of oral carcinogenesis by screening the methylation of repair genes in chronic smokers. DESIGN: Two groups were formed: Group 1: 16 smokers with consumption of 20 cigarettes/day for at least 10 years; and Group 2: 10 non-smoking. Exfoliative cytology of the tongue was performed, and the extracted DNA was treated by enzymes. The PCR Array System performed methylation screening to evaluate 22 DNA repair genes, and the results were validated by RT-qPCR for each gene with methylation levels ≥10%. RESULTS: Highest percentages of methylation were observed for MLH3 and XRCC1 genes (11-20% methylation) and in one case for MRE11A and PMS2 (>50% methylation). Statistical analysis showed significant differences in the expression of the genes MRE11A (p = 0.0002), PMS2(p = 0.0068), XRCC1 (p = 0.0080) and MLH3 (0.0057) between the two groups. CONCLUSION: The effects of chronic smoking on oral mucosa led to the methylation of genes MRE11A PMS2, XRCC1 and MLH3, but resulted in a reduction of gene expression of MRE11A and PMS2, which showed ≥50% methylation. These results provide evidence that smoking cause methylation and reduced expression of repair genes.

Granuloma Central de Células Gigantes: Relato de Caso Clínico / Central giant cell granuloma: a case report

O presente caso relata uma lesão central de células gigantes, apresentando, ainda, uma revisão da literatura com vistas ao diagnóstico e tratamento da lesão. Paciente do gênero masculino, leucoderma, 25 anos de idade procurou o serviço de cirurgia Buco-Maxilo-Facial da Universidade de Taubaté, apresentando uma lesão de grandes proporções em corpo mandibular esquerdo. Foram solicitados exames radiográficos e tomográficos, evidenciando uma área radiolúcida de aspecto unilocular, sugerindo as hipóteses diagnósticas de ameloblastoma, granuloma central de células gigantes e cisto ósseo aneurismático. Foi realizada a biópsia incisional, na qual se notou a presença de células gigantes multinucleadas e grupos de fibras colágenas com áreas de extravasamento de eritrócitos e depósitos de hemossiderina. Foram solicitados, também, exames bioquímicos do sangue para verificação dos níveis da fosfatase alcalina, os níveis de cálcio e fósforo e a dosagem de paratormônio, evidenciando-se valores normais para todos. O tratamento eleito foi curetagem cirúrgica da lesão com preservação dos dentes envolvidos no processo. A proservação do caso é de 24 (vinte e quatro) meses e demonstra franca recuperação, com evidente neoformação óssea, conforme análise clínica e radiográfica.

This study reports a case of central giant cell granuloma and also presents a review of the literature, focusing on the diagnosis and management of this lesion. A 25-year-old caucasian male, came to the Maxillofacial Surgery Outpatient Clinic of the University of Taubaté presenting a large lesion in the left mandibular body. Radiographic and computed tomography (CT) examinations revealed a unilocular radiolucent area suggesting the diagnoses of ameloblastoma, central giant cell granuloma and aneurysmal bone cyst. We performed an incisional biopsy, which revealed the presence of multinucleated giant cells embedded in a collagenous stroma with areas of extravasation of erythrocytes and hemosiderin deposits. Complementary biochemical examinations of the serum, demonstrated normal levels of alkaline phosphatase, calcium, phosphorus and parathyroid hormone. The treatment was surgical curettage of the lesion with preservation of the teeth involved. After twenty-four months of follow-up the patient shows a full recovery with no signs of recurrence and clear new bone formation, as evidenced by clinical and radiographic analyses.

Root surface treatment using diode laser in delayed tooth replantation: radiographic and histomorphometric analyses in rats.

UNLABELLED: BACKGROUND AIM: The aim of this study was to evaluate, by radiographic and histomorphometric analyses, the effects of high-power diode laser irradiation on the root surfaces of delayed replanted rat teeth. MATERIAL AND METHODS: Maxillary right incisors were extracted from 60 Wistar rats and kept dry for 60 min. Subsequently, the root canals were prepared and filled with calcium hydroxide paste. According to the root surface treatment before the replantation, the teeth were assigned to four groups (n = 15): G1 (negative control) - no root surface treatment; G2 (positive control) - treated with 2% sodium fluoride solution; G3 - irradiated with a high-power diode laser (810 nm, continuous mode, 1.0 W, 30 s); and G4 - irradiated with a diode laser using the same parameters as those used for G3 but in pulsed mode. The rats were euthanized after 15, 30, and 60 days of replantation. The specimens were digitally radiographed and processed for histomorphometric analysis to determine the average root resorption areas and to evaluate the histological events. RESULTS: The percentage of root resorption was in the following order: G1 > G2 > G4 > G3. Both histomorphometric and radiographic analyses showed significantly lower means (P < 0.05) of the occurrence of root resorption in the irradiated groups (G3 and G4) when compared to the control groups (G1 and G2). Replacement resorption and ankylosis were observed in histological sections only after 30 and 60 days; however, such events were not observed in G3. CONCLUSION: Root surface treatments with high-powered diode laser irradiation prior to delayed replantation reduced the occurrence of external root resorption compared to no treatment or sodium fluoride treatment at up to 60 days.

Clinicopathologic and immunohistochemical features of oral neurofibroma.

OBJECTIVE: The purposes of this study were to assess clinical, histopathological and immunohistochemical features of 22 oral neurofibromas (NFs) and discuss with previously described literature, addressing the main aspects regarding the differential diagnosis. MATERIALS AND METHODS: Immunohistochemical reactions included S-100, CD34, GLUT-1, EMA, Ki-67, p53 and Collagen IV and histochemical reactions for Alcian blue. RESULTS: Clinically, the preferential location was the maxillary bones, tongue and buccal mucosa. Microscopically, widely spread spindle-shaped cells with scant cytoplasm and elongated nuclei were observed. Immunostaining revealed that the tumor cells weakly expressed GLUT-1, Collagen IV, Ki-67 and p53. They were variably positive for CD34, S-100 protein and membrane epithelial antigen (EMA). CONCLUSIONS: The different types of nerve sheath cells observed in the present series reinforce the presence of heterogeneous population in NFs. The strong positivity for S-100 suggests that the lesions were more composed by S-100-positive Schwann cells than other cells. Besides, the high number of CD34-positive cells suggests that this marker can be useful for the differential diagnosis of NFs against PEN, traumatic neuromas and Schwannomas. Finally, the low immunostaining for p53 and Ki-67 may indicate that NFs massively composed by S-100-positive Schwann cells present low potential of aggressiveness and malignant transformation.

Oral granuloma formation after injection of cosmetic filler.

The increased use of orofacial fillers in cosmetic procedures has led to new diagnostic challenges for dentists and oral pathologists. Here, we describe a case with multiple oral foreign body granulomas, which were formed after a polymethylmetacrylate injection for cosmetic purposes.

HOXB5 expression in oral squamous cell carcinoma.

UNLABELLED: Human HOX genes encode transcription factors that act as master regulators of embryonic development. They are important in several processes such as cellular morphogenesis and differentiation. The HOXB5 gene in particular has been reported in some types of neoplasm, but not in oral cancer. OBJECTIVE: The present study investigated the expression of HOXB5 in oral squamous cell carcinoma (SCC) and in non-tumoral adjacent tissues, focusing on verifying its possible role as a broad tumor-associated gene and its association with histopathological and clinical (TNM) characteristics. MATERIAL AND METHODS: RT-PCR was performed to amplify HOXB5 mRNA in 15 OSCCs and adjacent non-tumoral epithelium. A possible association with TNM and histopathologic data was verified by the chi-square and post-hoc t-test. RESULTS: HOXB5 was amplified in 60% non-tumoral epithelium and in 93.3% carcinomas. No statistically significant differences were found regarding the HOXB5 mRNA expression and TNM or histological grade. CONCLUSION: HOXB5 is expressed in OSCCs and its role in cancer progression should be further investigated.

HOXB5 expression in oral squamous cell carcinoma

Human HOX genes encode transcription factors that act as master regulators of embryonic development. They are important in several processes such as cellular morphogenesis and differentiation. The HOXB5 gene in particular has been reported in some types of neoplasm, but not in oral cancer. OBJECTIVE: The present study investigated the expression of HOXB5 in oral squamous cell carcinoma (SCC) and in non-tumoral adjacent tissues, focusing on verifying its possible role as a broad tumor-associated gene and its association with histopathological and clinical (TNM) characteristics. MATERIAL AND METHODS: RT-PCR was performed to amplify HOXB5 mRNA in 15 OSCCs and adjacent non-tumoral epithelium. A possible association with TNM and histopathologic data was verifed by the chi-square and post-hoc t-test. RESULTS: HOXB5 was amplifed in 60 percent non-tumoral epithelium and in 93.3 percent carcinomas. No statistically signifcant differences were found regarding the HOXB5 mRNA expression and TNM or histological grade. CONCLUSION: HOXB5 is expressed in OSCCs and its role in cancer progression should be further investigated.

Diagnostic implications of oral intravascular papillary endothelial hyperplasia.

This study examined the clinical, histological, and immunohistochemical features as well as the differential diagnoses of oral intravascular papillary endothelial hyperplasia (IPEH) to aid clinicians and pathologists in its diagnosis. Clinical features of five oral IPEH cases were obtained from medical records, and all histopathological diagnoses were reviewed. Immunohistochemical reactions, including anti-CD-34, laminin, vimentin, estrogen receptor alpha, and Ki-67, were assessed. Microscopically, a reactive proliferation of vascular cells composed of small papillary structures with hypocellular and hyalinized cores arising in an organized thrombus was seen. CD-34, vimentin, and laminin staining were strongly positive, while estrogen receptor alpha was negative in all cases. A low percentage of cells were positive for Ki-67 in four of five lesions, but one case was strongly positive. A diagnosis of angiosarcoma was investigated and rejected. IPEH presents specific microscopic characteristics that along with clinical data lead to an accurate diagnosis. The general dentist, the first to participate in the diagnostic process, must share the responsibility for diagnosis with the pathologist, and they must work together to determine the correct diagnosis and management. Oral lesions of IPEH are uncommon. Their main significance is that they show a microscopic resemblance to angiosarcoma. Thus, clinicians should have more information regarding this benign entity. Finally, we suggest that in recurrent cases exhibiting strong immunolabeling of proliferative markers the possibility of angiosarcoma should be investigated.

The neural histogenetic origin of the oral granular cell tumor: An immunohistochemical evidence

Aims: Granular cell tumor (GCT) is a rare neoplasm that can appear in any site of the body, but most are located intraorally. Its histogenetic origin remains unclear. This report analyzes the immuno profile of 15 cases of granularcell tumors, occurring in 13 women and 2 men and the lesions were located on the tongue or upper lip. Patient ageranged from 7 to 52. Methods: The patients demographic data and the cytological and architectural features of the lesions were analyzed in oral GCTs (n = 15). The lesions were also submitted to a panel of immunohisto chemical stains with antibodies against S-100, p75, NSE, CD-68, Ki-67, Synaptofisin, HHF-35, SMA, EMA, Chromogranin, Progesterone, Androgen and Estrogen. Results: Among the fifteen cases analyzed, the most common location was the tongue (84.6%). Histologically,the tumors exhibited cellular proliferation composed mainly by polygonal cells presenting an abundant granulareosinophilic cytoplasm. The nuclei were central, and the cell membranes were moderately clear. No mitotic figures were observed. The immunohistochemical analysis showed positivity in all cases for S-100, p75, NSE andCD-68, and no immunoreactivity for Ki-67, Synaptofisin, HHF-35, SMA, EMA, Chromogranin, Progesterone,Androgen and Estrogen. Conclusion: The immunoprofile of granular cell tumors showed nerve sheath differentiation – lending support to their neural origin – and helping to establish a differential diagnosis between this lesion and other oral granularcell tumors, whether benign or malignant (AU)

The neural histogenetic origin of the oral granular cell tumor: an immunohistochemical evidence.

AIMS: Granular cell tumor (GCT) is a rare neoplasm that can appear in any site of the body, but most are located intraorally. Its histogenetic origin remains unclear. This report analyzes the immunoprofile of 15 cases of granular cell tumors, occurring in 13 women and 2 men and the lesions were located on the tongue or upper lip. Patient age ranged from 7 to 52. METHODS: The patients demographic data and the cytological and architectural features of the lesions were analyzed in oral GCTs (n=15). The lesions were also submitted to a panel of immunohistochemical stains with antibodies against S-100, p75, NSE, CD-68, Ki-67, Synaptofisin, HHF-35, SMA, EMA, Chromogranin, Progesterone, Androgen and Estrogen. RESULTS: Among the fifteen cases analyzed, the most common location was the tongue (84.6%). Histologically, the tumors exhibited cellular proliferation composed mainly by polygonal cells presenting an abundant granular eosinophilic cytoplasm. The nuclei were central, and the cell membranes were moderately clear. No mitotic figures were observed. The immunohistochemical analysis showed positivity in all cases for S-100, p75, NSE and CD-68, and no immunoreactivity for Ki-67, Synaptofisin, HHF-35, SMA, EMA, Chromogranin, Progesterone, Androgen and Estrogen. CONCLUSION: The immunoprofile of granular cell tumors showed nerve sheath differentiation--lending support to their neural origin--and helping to establish a differential diagnosis between this lesion and other oral granular cell tumors, whether benign or malignant.

Time- and concentration-dependent cytotoxicity of antibiotics used in endodontic therapy.

OBJECTIVE: New drugs have to be assessed in endodontic therapy due to the presence of microorganisms resistant to therapeutic procedures. Thus, this study evaluated the time- and concentration-dependent cytotoxicity of different antibiotics used in endodontic therapy. MATERIAL AND METHODS: Human gingival fibroblasts were treated and divided into the following experimental groups: Group I - control; Group II - ciprofloxacin hydrochloride; Group III - clyndamicin hydrochloride; and Group IV - metronidazole. Each drug was used at concentrations of 5, 50, 150, and 300 mg/L for 24, 48, 72, and 96 h. Cytotoxicity was evaluated by the MTT assay [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and spectrophotometric reading of ELISA plates. The results were analyzed by BioEstat 4.0 software using Kruskal-Wallis and Dunn's tests at a significance level of 5%. Cell viability was assessed for the different concentrations and times. RESULTS: All drugs presented dose-dependent cytotoxicity. Concentrations of 5 and 50 mg/L produced viable fibroblasts at all experimental times in all groups. CONCLUSIONS: Cell viability at 24 h was greater than in the other experimental times. Comparison between the same concentrations of antibiotics at different times showed that metronidazole presented the highest cell viability at 72 and 96 h compared to the other antibiotics, whereas clyndamicin hydrochloride showed higher cell viability at 72 h than ciprofloxacin hydrochloride.

Time- and concentration-dependent cytotoxicity of antibiotics used in endodontic therapy

OBJECTIVE: New drugs have to be assessed in endodontic therapy due to the presence of microorganisms resistant to therapeutic procedures. Thus, this study evaluated the time- and concentration-dependent cytotoxicity of different antibiotics used in endodontic therapy. MATERIAL AND METHODS: Human gingival fibroblasts were treated and divided into the following experimental groups: Group I - control; Group II - ciprofoxacin hydrochloride; Group III - clyndamicin hydrochloride; and Group IV - metronidazole. Each drug was used at concentrations of 5, 50, 150, and 300 mg/L for 24, 48, 72, and 96 h. Cytotoxicity was evaluated by the MTT assay [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and spectrophotometric reading of ELISA plates. The results were analyzed by BioEstat 4.0 software using Kruskal-Wallis and Dunn's tests at a signifcance level of 5 percent. Cell viability was assessed for the different concentrations and times. RESULTS: All drugs presented dose-dependent cytotoxicity. Concentrations of 5 and 50 mgjL produced viable fibroblasts at all experimental times in all groups. CONCLUSIONS: Cell viability at 24 h was greater than in the other experimental times. Comparison between the same concentrations of antibiotics at different times showed that metronidazole presented the highest cell viability at 72 and 96 h compared to the other antibiotics, whereas clyndamicin hydrochloride showed higher cell viability at 72 h than ciprofoxacin hydrochloride.

Giant cell fibroma of the maxillary gingiva in children: a case report.

The purpose of this paper is to describe a giant cell fibroma in the maxillary gingiva of an 11-year-old girl. After excisional biopsy, histological examination showed the presence of numerous giant, multinucleated, stellate-shaped cells dispersed throughout the fibrous tissue of the lamina propria. No recurrence was observed after the 1-year follow-up. Since this lesion is clinically similar to other non-neoplastic lesions and very uncommon in children, establishing a correct diagnosis can be difficult and achieved only based on specific histological characteristics. Thus, it is important that pediatric dentists have knowledge about this uncommon lesion.

Interleukin-1 beta and interleukin-8 in healthy and inflamed dental pulps.

UNLABELLED: After aggression to the dental pulp, some cells produce cytokines in order to start and control the inflammatory process. Among these cytokines, interleukin-1 beta (IL-1beta) and interleukin-8 (IL-8) emerge as important ones. OBJECTIVE: The purpose of this study was to analyze the location, distribution and concentration of these cytokines in healthy and inflamed dental pulps. MATERIAL AND METHODS: Twenty pulps, obtained from healthy third molars (n=10) and from pulpectomies (n=10) were used for the study, with half of each group used for immunohistochemistry and half for protein extraction and ELISA assays. Fibroblasts obtained from healthy dental pulps, stimulated or not by Escherichia coli lipopolysaccharide (LPS), in order to simulate aggression on the cell cultures, were also used and analyzed by ELISA for IL-1beta and IL-8 as complementary information. Data obtained from immunohistochemistry were qualitatively analyzed. Data obtained from ELISA assays (tissue and cells) were statistically treated by the t-test (p<0.05). RESULTS: Immunohistochemically, it was observed that inflamed pulps were strongly stained for both cytokines in inflammatory cells, while healthy pulps were not immunolabeled. ELISA from tissues quantitatively confirmed the higher presence of both cytokines. Additionally, cultured pulp fibroblasts stimulated by LPS also produce more cytokines than the control cells. CONCLUSIONS: It may be concluded that inflamed pulps present higher amounts of IL-1beta and IL-8 than healthy pulps and that pulp fibroblasts stimulated by bacterial LPS produce higher levels of IL-1beta and IL-8 than the control group.

Interleukin-1 beta and interleukin-8 in healthy and inflamed dental pulps

After aggression to the dental pulp, some cells produce cytokines in order to start and control the inflammatory process. Among these cytokines, interleukin-1 beta (IL-1β) and interleukin-8 (IL-8) emerge as important ones. OBJECTIVE: The purpose of this study was to analyze the location, distribution and concentration of these cytokines in healthy and inflamed dental pulps. MATERIAL AND METHODS: Twenty pulps, obtained from healthy third molars (n=10) and from pulpectomies (n=10) were used for the study, with half of each group used for immunohistochemistry and half for protein extraction and ELISA assays. Fibroblasts obtained from healthy dental pulps, stimulated or not by Escherichia coli lipopolysaccharide (LPS), in order to simulate aggression on the cell cultures, were also used and analyzed by ELISA for IL-1β and IL-8 as complementary information. Data obtained from immunohistochemistry were qualitatively analyzed. Data obtained from ELISA assays (tissue and cells) were statistically treated by the t-test (p<0.05). RESULTS: Immunohistochemically, it was observed that inflamed pulps were strongly stained for both cytokines in inflammatory cells, while healthy pulps were not immunolabeled. ELISA from tissues quantitatively confirmed the higher presence of both cytokines. Additionally, cultured pulp fibroblasts stimulated by LPS also produce more cytokines than the control cells. CONCLUSIONS: It may be concluded that inflamed pulps present higher amounts of IL-1β and IL-8 than healthy pulps and that pulp fibroblasts stimulated by bacterial LPS produce higher levels of IL-1β and IL-8 than the control group.

Intravascular papillary endothelial hyperplasia: Report of 4 cases with immunohistochemicalfindings

Intravascular papillary endothelial hyperplasia (IPEH) is a benign endothelial proliferation, usually intravascular,that may mimic angiosarcoma. In this report, four new cases of IPEH involving the oral region are described.The affected sites were the lower lip, labial comissure and the submandibular region. After clinical evaluation, thecomplete removal of the lesions showed a circumscribed and soft mass. Histologically, the major feature was areactive proliferation of endothelial cells composed of small papillary structures with hypocellular and hyalinizedcores arising in an organized thrombus. Immunohistochemical staining for CD34 was strongly positive in endothelialcells. Vimentin and laminin immunolabelling were also consistent with a vascular origin. In order to verifythe proliferative potential of the lesions, the Ki-67 antibody was used, revealing low percentage of labeled cells(<20%). No immunoreactivity for GLUT-1 was observed. Since the complete removal is curative, no additionaltreatment was necessary, and no signs of recurrence had been observed until now. Due to the particular features ofIPEH, it is important for pathologists and clinicians to become familiar with this lesion. Additionally, the specifichistological arrangement, including the absence of cellular pleomorphism, mitotic activity and necrosis, representsa guide to help in the differential diagnosis. Moreover, the vascular origin and the proliferative index should beassessed by immunohistochemistry in order to provide an accurate diagnosis (AU)

Intravascular papillary endothelial hyperplasia: report of 4 cases with immunohistochemical findings.

Intravascular papillary endothelial hyperplasia (IPEH) is a benign endothelial proliferation, usually intravascular, that may mimic angiosarcoma. In this report, four new cases of IPEH involving the oral region are described. The affected sites were the lower lip, labial comissure and the submandibular region. After clinical evaluation, the complete removal of the lesions showed a circumscribed and soft mass. Histologically, the major feature was a reactive proliferation of endothelial cells composed of small papillary structures with hypocellular and hyalinized cores arising in an organized thrombus. Immunohistochemical staining for CD34 was strongly positive in endothelial cells. Vimentin and laminin immunolabelling were also consistent with a vascular origin. In order to verify the proliferative potential of the lesions, the Ki-67 antibody was used, revealing low percentage of labeled cells (<20%). No immunoreactivity for GLUT-1 was observed. Since the complete removal is curative, no additional treatment was necessary, and no signs of recurrence had been observed until now. Due to the particular features of IPEH, it is important for pathologists and clinicians to become familiar with this lesion. Additionally, the specific histological arrangement, including the absence of cellular pleomorphism, mitotic activity and necrosis, represents a guide to help in the differential diagnosis. Moreover, the vascular origin and the proliferative index should be assessed by immunohistochemistry in order to provide an accurate diagnosis.

Atypical presentation of oral basaloid squamous cell carcinoma.

AIM: The purpose of this report is to present the clinical and histological features of a basaloid squamous cell carcinoma (BSCC) occurring in the retromolar trigone of a 59-year-old man and to relate its immunohistochemical characteristics. BACKGROUND: BSCC is an aggressive distinct variant of squamous cell carcinoma (SCC) requiring recognition as a separate entity from SCC due to its peculiar behavior. CASE REPORT: A clinical examination revealed a 12x07x07 mm nodular mass with a rubbery consistency, defined borders, covered by reddish mucosa and an absence of bleeding upon palpation. Histologically, nests and cords of closely packed, moderately pleomorphic basaloid cells with nuclear palisading along the periphery of the neoplastic nests surrounded by a fibrous stroma were found. SUMMARY: Since this tumor can mimic other neoplasms such as adenoid cystic carcinoma, neuroendocrine carcinoma, and basal cell adenocarcinoma, histological features are essential to differentiate between them. Furthermore, immunohistochemical testing can provide valuable diagnostic information that can have a profound impact on treatment options and the prognosis. CLINICAL SIGNIFICANCE: BSCC needs to be differentiated from other neoplasms as early as possible because of its adverse prognosis. Clinicians are advised to conduct a mucosal evaluation during oral examinations and take a thorough medical history which could ultimately save the life of a patient.

Expressão do RNA mensageiro de genes HOX em linhagens celulares de carcinomas epidermoides de cabeça e pescoço / HOX genes mRNA expression in head and neck squamous cell carcinoma cell lineages

Os genes HOX são importantes para o controle do desenvolvimento embrionário e regulam aspectos da morfogênese e diferenciação celular. A associação entre os genes HOX e o processo da oncogênese tem sido verificada em casos de carcinomas de cólon, pele, rim, pulmão, mama, leucemias e outros tipos de câncer. O objetivo deste trabalho foi verificar a expressão de genes HOX em linhagens celulares de carcinomas epidermoides de cabeça e pescoço. Para tanto, utilizamos a técnica RT-PCR para analisar a expressão de três grupos de genes HOX em linhagens celulares de carcinomas epidermoides de cabeça e pescoço: HN-6, HN-19, HN-30 e HN-31, utilizando-se os primeiros degenerados HOX1, HOX2 e HOX3 e coamplificação com o gene constitutivo da β-actina. Material de gengiva humana e embrião de camundongo foram utilizados como controle de expressão do gene HOX. Os resultados obtidos mostraram que a expressão dos genes HOX apresentou padrão semelhante aos controles utilizados. Houve, porém, subexpressão do grupo HOX1 nas linhagens HN-6 e HN-19 e superexpressão do grupo HOX-2 na linhagem HN-31. Esses achados nos permitem levantar a hipótese de que os genes HOX podem participar das alterações moleculares observadas em carcinomas epidermoides de cabeça e pescoço.