Introdução: A rinossinusite crônica (RSC), doença multifatorial, na qual podem estar envolvidos fatores genéticos e ambientais, ainda tem muitos aspectos obscuros na sua patogênese. A genética tem se mostrado promissora na elucidação dessa complexa doença. Alguns estudos apontam que a expressão de interleucina (IL) 22 se apresenta reduzida em pacientes com RSC, podendo resultar também na redução da barreira epitelial e diminuição da produção de citocinas pró-inflamatórias Th1. Objetivos: Pesquisar a frequência dos polimorfismos no gene IL22RA1 (receptor subunidade alfa um da interleucina 22) em pacientes portadores de RSC com e sem pólipos nasais e em indivíduos normais, utilizando a técnica de sequenciamento, pelo método de Sanger, para análise de mutações; comparar as frequências dos polimorfismos encontrados no gene IL22RA1 entre os grupos e com a literatura médica e também comparar a técnica de Sanger com outras técnicas convencionais descritas na literatura. Casuística e Métodos: Foram avaliados 247 pacientes, no período de maio de 2011 a fevereiro de 2016, subdivididos em três grupos: 122 pacientes portadores de RSC com pólipos nasais (RSCcPN), 21 casos de RSC sem pólipos nasais (RSCsPN) e 104 voluntários sem sintomatologia nasal. Foram colhidas amostras de sangue venoso periférico de todos os casos e controles, e realizada a extração de DNA, com posterior análise das mesmas. Após a exclusão das perdas, restaram 70 casos de RSCcPN, 14 de RSCsPN e 68 controles. Resultados: O sequenciamento apontou 10 polimorfismos no gene IL22RA1, nos exon 2 (rs10903022, c.113_114insA/Q26Pfs*11, c.74T>A e c.141C>A), exon 4 (rs17852649), exon 5 (rs16829204), exon 6 (rs142356961) e exon 7 (rs17852648, rs34967816 e rs3795299). Os polimorfismos encontrados nos exons 2 (em homozigose), 5 e 6 foram exclusivos do grupo das patologias analisadas (RSC com e sem PN), sendo as duas últimas consideradas variáveis não sinônimas, ou seja, com capacidade de alterar a estrutura da proteína, podendo produzir impacto na patogênese da RSC. A alteração do exon 6 foi a única variante encontrada, com frequência do alelo menor (MAF) inferior a 0,01, exclusiva do grupo RSCcPN. Conclusões: Foram detectados três polimorfismos no gene IL22RA1, que até o momento não estão descritos na literatura, sendo a inserção c.113_114insA/Q26Pfs*11, possivelmente patogênica, com frequência maior nos grupos com RSC. O polimorfismo rs17852649 em heterozigose no exon 4, foi o único com diferença estatística, com predominância do alelo mutado no grupo controle, podendo conferir proteção contra o fenótipo. Também se destaca o polimorfismo rs142356961, no exon 6, do tipo não sinônimo, ou seja, capaz de alterar a estrutura final da proteína, com índice MAF<0,01, sendo exclusiva de pacientes negros portadores de RSCcPN. Estudos de replicação e com maiores coortes serão necessários para determinar se os achados do presente estudo se deram ao acaso. / Introduction: Chronic rhinosinusitis (CRS), a multifactorial disease, with genetic and environmental factors that may be involved, still have many aspects of its pathogenesis unknown. Genetics has shown itself promising in the elucidation of this complex disease. Some studies have indicated that the expression of IL-22 is reduced in patients with CRS, which may result in reduction of the epithelial barrier and decrease in the production of Th1 proinflammatory cytokines. Objectives: To investigate the frequency of polymorphisms in the IL22RA1 gene in patients with chronic rhinosinusitis with and without nasal polyps and in individuals without these pathologies, using the Sanger sequencing technique for mutation analysis; to compare the frequencies of the polymorphisms found in the IL22RA1 gene between the groups and the medical literature and also to compare the Sanger technique with other conventional techniques in the medical literature. Casuistic and Methods: From May 2011 to February 2016, 247 patients were evaluated, subdivided into three groups: 122 patients with chronic rhinosinusitis with nasal polyps (CRSwNP), 21 cases of chronic rhinosinusitis without nasal polyps (CRSsNP) and 104 volunteers without nasal symptoms. Samples of peripheral venous blood were collected from all cases and controls, and DNA extraction was performed, with subsequent analysis at the Molecular Genetics Laboratory - Ribeirão Preto Medical School Blood Center - USP. After the loss exclusion, there were 70 cases of CRSwNP, 14 CRSsNP and 68 controls. Results: Sequencing indicated 10 polymorphisms in the IL22RA1 gene, exon 2 (rs10903022, c.113_114insA / Q26Pfs * 11, c.74T> A and c.141C> A), exon 4 (rs17852649), exon 5 (rs16829204), exon 6 (rs142356961) and exon 7 (rs17852648, rs34967816 and rs3795299). Polymorphisms in exons 2 (in homozygosis), 5 and 6 were exclusive from the analyzed pathologies group (RSC with and without NP), the latter two being considered non-synonymous variables, that is, with capacity to alter the protein structure, being able to produce impact on the pathogenesis of CRS. The exon 6 alteration was the only variant found, with the minor allele frequency (MAF) under 0.01, exclusive of the RSCcPN group. Conclusions: Three polymorphisms were detected in the IL22RA1 gene, which until now are not described in the literature, and the possibly pathogenic insert c.113_114insA / Q26Pfs * 11, with a higher frequency in the groups with CRS. The polymorphism rs17852649 in heterozygosis in exon 4 was the only one with a statistical difference, with predominance of the mutated allele in the control group, which could confer protection against the phenotype. Also notable is the polymorphism rs142356961, in exon 6, of the non-synonymous type, that is, capable of altering the final structure of the protein, with MAF index <0.01, being exclusive in black patients with chronic rhinosinusitis with nasal polyps. Replication studies and larger cohorts are necessary to rule out the findings at random.

Magister Scientiae - MSc / Several abnormal conditions, including some cancers, have been associated with changes in the membrane lipid and FA composition. Dietary fat serves as a major source of lipids and FA, particularly the polyunsaturated fatty acids (PUFA), n-6 and n-3. High intakes of n-6 PUFA have been linked to the development of colon cancer in association with low n-3 PUFA intake. Therefore understanding the differences in the lipid and FA profiles between cancer and normal cells in the colon, and the role diet plays in these factors may be invaluable in understanding their role in carcinogenesis. This study compares the lipid profile of azoxymethane (AOM) induced colon polyps to that of the surrounding mucosa tissue in rats fed a diet high in n-6 PUFA. Male Fischer rats were fed the AIN-76A diet containing sunflower oil that has high n-6 PUFA content for a period of nine months. Results indicate that the lipid and FA content of the colon polyps differs significantly from the surrounding mucosa. Colon polyps had an increase in membrane phopholipids phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Changes in membrane fluidity were indicated by the decrease (0.05) in the PC/PE and cholesterol/phospholipids (chol/PL) ratios, and increase (0.05) in the polyunsaturated FA/saturated FA (P/S) ratio. Metabolism of FA was significantly altered in the polyps favouring n-6 FA metabolism and the production of prostaglandin E2. No clear indication of impaired & Delta;6-desauturase enzyme activity was noticed. Increases in the n-6 PUFA content could be a reflection of the dietary FA intake that increases FA incorporation in the polyps. Changes in the FA parameters of the polyps, particularly an increase in C20:4n-6 and the n6/n3 ratio have been shown to contribute to the rapid growth of cancer tissue. These lipid changes associated with the development of colon polyps could provide unique targets for developing strategies in chemoprevention by dietary manipulation. / South Africa

Diminutive polyps found on flexible sigmoidoscopy are predominantly hyperplastic, but it is impossible to rely on endoscopic appearance to make an accurate diagnosis. Colonoscopy, polypectomy, and full pathologic evaluation are recommended for all such polyps. Follow-up care varies depending on the nature of the lesion.

Coral reefs are among the most biodiverse ecosystems in the world, being essential for marine life. The engineers of these ecosystems, reef-building corals, live in association with a great diversity of microorganisms, which can affect their host’s health in beneficial or detrimental manners. Corals are currently threatened by climate change and other environmental stressors, that lead to the phenomenon of coral bleaching, in which these animals lose their endosymbiotic algae. Even though the stressors that cause coral bleaching are known, the exact cellular and molecular mechanisms that provoke this process are still undiscovered. The lack of information regarding micro-scale processes that happen in unhealthy corals could be resolved with more efforts in developing micro-scale studying models. The use of individual polyps that bail-out of the coral skeleton induced by acute stress has been suggested as a model to study these processes. However, little is known about how these polyps change after bailing-out of a colony, which could become a problem once reliable models should be consistent and well understood. Thus, investigating these changes and optimizing a methodology to minimize them is crucial to establish these polyps as models to study corals. Herein, we investigated microbiological changes of isolated polyps by performing an experiment to study shifts in their microbiome after the separation from the colony. Before the experiment, different methods to isolate polyps were tested to find the one that granted the highest survival. After finding that salinity-induced separation was the most efficient, this method was used to study the microbiome of coral polyps. We found that while no significant changes in the microbiome could be observed immediately after the separation of polyps from their colony compared to coral fragments, this pattern changed after two weeks. We propose that the maintenance of polyps without fixation to a substrate might be the cause for such changes, and that polyps able to attach to a substrate and regrow as a colony might still recover a microbiome composition closer to coral fragments. Finally, a new microfluidic device for fixation and maintenance of coral polyps was developed and tested for use in future experiments.

BACKGROUND: Numerous epidemiologic studies have identified obesity as a vital risk factor for the development of colorectal cancer (CRC). More recently, obesity has been linked to the development of colorectal adenomatous polyps (adenomas), the precursor lesion of up to 80% of CRCs. The extent to which weight loss could reduce risk in obese patients is unclear. PROPOSED PROJECT: The proposed study is a randomized clinical trial that aims to evaluate the relationship between weight reduction and the prevalence of recurrent (metachronous) adenomas among obese patients in a safety-net health care setting. The intervention group will participate in a comprehensive, individually structured weight loss program in order to achieve successful long-term weight loss. The control group will receive no special recommendations about weight loss other than as part of “usual care”. Anthropometric measures (weight in kilograms [kg], height in meters squared [m2] and body mass index [BMI]) will be monitored annually until the time of surveillance colonoscopy which will occur in accordance with the U.S. Multi-Society Task Force recommendations. Statistical methods will be used to compare rates of recurrent adenomas among the two study groups after adjustments for duration of follow-up and potential confounders. CONCLUSION/SIGNIFICANCE: The results of this study will provide new evidence to support weight reduction as a preventive strategy for reducing CRC risk among obese patients.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.

Introdução: A patogenia da rinossinusite crônica com polipose nasossinusal não está completamente estabelecida e existem algumas explicações para essa doença como os superantigenos, o desequilíbrio inflamatório e, mais recentemente, o biofilme. Objetivos: Avaliar a associação entre a presença do biofilme e a presença de rinossinusite crônica com polipose nasossinusal. Avaliar o quadro clínico e radiológico pré-operatória e pós-operatória segundo a presença do biofilme. Métodos: Este é uma estudo realizado em um hospital terciário universitário. A primeira parte foi um estudo caso-controle com um grupo de 33 pacientes consecutivos com rinossinusite crônica com polipose nasossinusal submetidos a cirurgica endoscópica nasossinusal e um grupo controle de 27 pacientes submetidos a septoplastia para tratamento de obstrução nasal. As amostras da mucosa foram coletadas no intra-operatório para avaliação por microscopia eletrônica de varredura para determinar a presença do biofilme. A segunda parte foi um estudo prospectivo em que dados pré-operatórios e pós-operatórios foram registrados, incluindo avaliações padronizadas da qualidade de vida doença-específica relacionadas à obstrução nasal e à rinossinusite, da endoscopia nasal e da tomografia de cavidades paranasais. A análise estatísca foi realizada. Para todos os testes um p=0.05 foi considerado significativo. Resultados: Os biofilmes foram encontrados em 72.7% (24/33) dos pacientes com rinossinusite crônica com polipose nasossinusal e 48.1% (13/27) dos pacientes submetidos a septoplastia (Odd ratio=2.87, IC95% 0.9796-8.419, p=0.051). Este foi o primeiro estudo a analisar o efeito da presença do biofilme nos resultados pós-operatórios com medidas padronizadas de um grupo de pacientes apenas com rinossinusite crônica com polipose nasossinusal. O biofilme estava presente em 72.4% (21/29) dos pacientes que completaram o seguimento. Os pacientes com biofilmes apresentaram uma pior pontuação pré-operatória NOSE e Lund-Kennedy estatísticamente significativos, mas uma mediana semelhante na pontuação total do SNOT-20. Os pacientes com biofilme apresentaram uma melhor resultado na pontuação Lund-Kennedy (p=0.036). Estes pacientes apresentaram piores resultados no SNOT-20 e resultados similares quanto ao NOSE e o Lund-Mackay. Conclusão: Os biofilmes foram demonstrados presentes nos pacientes submetidos a cirurgia endoscópica funcional para rinossinusite crônica com polipose nasossinusal mas também nos controles. Embora a prevalência não tenha sido diferente significativamente, o intervalo de confiança extremamente amplo de 95%, que apenas cruza a unidade, sugere que uma diferença significativa pode ter sido perdida por causa do baixo poder estatístico e estudos futuros serão necessários. Os biofilmes estiveram relacionados com pior qualidade de vida doença-específica pré-operatória NOSE e avaliação endoscópica (Lund-Kennedy), e melhores resultados endoscópicos. Nossos resultados sugerem que nos pacientes com uma melhora clínica significativa após a cirurgia, o biofilme representou um papel mais predominante na fisiopatologia da doença. Neste subgrupo, a cirurgia provavelmente removeu a quantidade de biofilme necessária para restaurar o desequilíbrio inflamatório na mucosa / Introduction: The pathogenesis of chronic rhinosinusitis with nasal polyps is not completely established and there are some explanations for this disease, such as superantigens, inflammatory imbalance and, more recently, biofilms. Objective: Evaluate the association of biofilms presence and chronic rhinosinusitis with nasal polyps. Evaluate outcomes after sinus surgery for chronic rhinosinusitis with nasal polyps according to the presence of biofilms. Methods: This is a University based-tertiary care center study. The first part was a case-control study that evaluated a group of 33 consecutive patients undergoing functional endoscopic sinus surgery for chronic rhinosinusitis with nasal polyps and a control group of 27 patients undergoing septoplasty for nasal obstruction treatment. Mucosal samples were harvested intra-operatively for scanning electron microscopic examination to determine biofilms presence. The second part was a prospective study. Preoperative and follow up data were recorded, including standardized evaluations of disease-specific quality of life related to nasal obstruction and rhinosinusitis, of nasal endoscopy and sinus computer tomography scan. Statistical analysis was performed. For all statistical tests p=0.05 was considered significant. Results: Biofilms were found in 72.7% (24/33) of chronic rhinosinusitis with nasal polyps patients and in 48.1%(13/27) of septoplasty patients (Odds ratio = 2.87, CI95% from 0.9796 to 8.419, p=0.051). This was the first report to analyze the effect of biofilms in outcomes with standardized measures of a group of only chronic rhinosinusitis with nasal polyps patients. Biofilms were present in 72.4% (21/29) of these patients. Patients with biofilms had a statistically significant worst preoperative score related to nasal obstruction and nasal endoscopy, but a similar median sinusitis total score. Patients with biofilms presented better Lund-Kennedy outcome (-3[5]vs.-1[2],U=46.0,p=0.036), but the best endoscopic improvement might reflect the worst clinical preoperative status. These patients had worst outcomes in SNOT-20 (-0.75[1.15]vs.-1.30[1.32],U=69.0,p=0.21) and similar outcomes in NOSE(-55.0[50.0] vs. -60.0[50.0], U=81.0,p=0.67) and Lund-Mackay (-4[5]vs.-4[4]),U=75.5,p=0.49). Patients with biofilms presented better Lund-Kennedy outcome (p=0.036). There was a correlation among some QoL outcome scores in both groups. Conclusion: Biofilms were demonstrated to be present in patients undergoing functional endoscopic sinus surgery for chronic rhinosinusitis with nasal polyps but also in controls. Although the prevalence was not significantly different, the extremely wide 95% confidence interval, which just crosses unity, suggests that a meaningful clinical difference may have been missed because of low statistical power and that further study is necessary. Biofilms were related with worst preoperative disease-specific quality of life questionnaire (NOSE) and endoscopic evaluation (Lund-Kennedy), and better endoscopic outcome. Our findings suggest that in patients with a significant clinical improvement after surgery, the biofilm had a more predominant role in the pathophysiology of the disease. In this subgroup, the surgery probably removed the amount of biofilms needed to restore the mucosal inflammatory imbalance

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Made available in DSpace on 2015-07-22T20:50:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-26. Added 1 bitstream(s) on 2015-08-11T03:25:58Z : No. of bitstreams: 1 Publico-11853.pdf: 1847638 bytes, checksum: 58d741297f37fd108b68cf301ea6653b (MD5) / Objetivo: Avaliar a presença do polimorfismo genético do receptor da progesterona (PROGINS) bem como as variáveis clínicas e epidemiológicas de risco para câncer de endométrio em mulheres com pólipos endometriais na pós-menopausa. Casuística e Métodos: Comparou-se em estudo caso-controle 154 mulheres menopausadas com pólipos endometriais benignos e 400 controles normais na pós-menopausa, quanto à presença do PROGINS, por meio da Reação em Cadeia da Polimerase (PCR). O grupo de pólipos endometriais foi comparado a 118 pacientes do grupo controle no tocante às variáveis clínicas e epidemiológicas de risco para câncer de endométrio. Estas variáveis foram também comparadas entre os pólipos benignos e malignos. Resultados: A comparação entre o grupo de pólipos benignos e o grupo controle mostrou significância estatística (p<0,05) para as varáveis: idade (média de 61,7 x 57,5 anos), raça não-branca (44,8% x 22,9%), anos da menopausa (média de 12,9 x 9,2 anos), paridade (média de 4,5 x 3,4 filhos), uso de tamoxifeno (5,2% x 0%), hipertensão arterial (54,5% x 29,7%) e antecedente de câncer de mama (10,4% x 0,8%) respectivamente. Após o ajuste para a idade, permaneceram com significância estatística, apenas a paridade (OR=1,13), a hipertensão arterial (OR=2,19) e o antecedente de câncer de mama (OR=14,44). Seis casos (3,75%), foram diagnosticados como pólipos malignos, nestes casos, sangramento na pós-menopausa e o tamanho grande do pólipo estiveram sempre presentes, enquando que nos pólipos benignos esta frequência foi de 23,4% para sangramento e 54,5% para pólipo grande. A hipertensão arterial foi bem mais frequente no grupo de pólipos malignos, 83,3% x 54,5% nos pólipos benignos. Não houve diferença estatisticamente significante entre os grupos quanto à presença do PROGINS, sendo no grupo de pólipos benignos a distribuição entre homozigoto selvagem, heterozigoto e homozigoto mutado de 79,9%, 19,5% e 0,6% respectivamente. No grupo controle (N=400) esta distribuição foi de 78,8%, 20,8% e 0,5% respectivamente. Conclusões: A presença do PROGINS não mostrou associação significativa com pólipos endometriais. As variáveis epidemiológicas significantemente associadas à presença de pólipos endometriais, após o ajuste para idade, foram a paridade, hipertensão arterial e o antecedente de câncer de mama (implícito o uso de tamoxifeno), além da idade mais avançada. Em nosso estudo, pólipos endometriais malignos estiveram sempre associados à presença de sangramento na pós-menopausa e tamanho grande do pólipo, sendo a hipertensão arterial achado bastante frequente. / Purpose: To evaluate the genetic polymorphism of the progesterone receptor (PROGINS), as well as clinical and epidemiological risk factors for endometrial cancer in postmenopausal women with endometrial polyps. Methods: A case control study was designed with 154 postmenopausal women with endometrial polyps, compared to a normal control group of 400 postmenopausal women. The genotyping of PROGINS polymorphism was determined by polymerase chain reaction. The group of polyps was compared to 118 normal postmenopausal controls regarding clinical and epidemiological variables. These variables were also compared between benign and malignant endometrial polyps. Results: The epidemiological variables among the group of endometrial polyps and normal control, showed statistical significance (p<0,05) for age: media of 61,7 and 57,5 years, ethnicity non-white 44,8% and 22,9%, time since menopause media of 12,9 and 9,2 years, parity media of 4,5 and 3,4 sons, tamoxifen use 5,2% and 0%, hypertension 54,5% and 29,7% and history of breast cancer 10,4% and 0,8% respectively. After age adjust, statistical significance, remained only for parity (OR=1,13), hypertension (OR=2,19) and history of breast cancer (OR=14,44). Postmenopausal bleeding and large polyps were present in all cases of malignancy. Hypertension was also very frequent in malignant polyps (83,3% and 54,5% respectively). The presence of PROGINS had no statistical significance between the group of polyps and the normal control (N=400). The presence of wild homozygosis genotype, heterozygosis and mutant homozygosis was 79,9%, 19,5% and 0,6% respectively for the polyp group, and 78,8%, 20,8% and 0,5% for the control group (p=0,208). Conclusions: There was no significant association between the presence of PROGINS and endometrial polyps. After age adjust, epidemiological variables significantly associated to endometrial polyps were elderly age, parity, hypertension, and history of breast cancer (implicit tamoxifen use). Malignant polyps in this study were always associated to postmenopausal bleeding, large polyps and frequently associated to hypertension. / TEDE / BV UNIFESP: Teses e dissertações

Orientador: Albina Messias de Almeida Milani Altemani / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-16T12:03:45Z (GMT). No. of bitstreams: 1 Barreto_IcleiaSiqueira_D.pdf: 12646702 bytes, checksum: 9cc75301ed45a05b163a8e355ac78a7e (MD5) Previous issue date: 2010 / Resumo: Pólipos tonsilares são lesões não neoplásicas usualmente constituídas por quantidades variáveis de tecidos linfóide, vascular e conjuntivo. Todos são considerados como proliferações hamartomatosas, mas o perfil dos componentes vascular e conjuntivo, necessita de estudo mais aprofundado. O sistema vascular das tonsilas é complexo e inclui estruturas altamente especializadas (Vênulas do Endotélio Alto- VEA), envolvidas no tráfico dos linfócitos para os tecidos linfóides. Foram estudados 14 pólipos tonsilares e 26 tonsilas palatinas, usando CD34 (para vasos sanguíneos e VEA), CD105 (para VEA), D2-40 (para vasos linfáticos), Ki-67 (para índice proliferativo), colágenos I e III, fibronectina e tenascina-C (para proteínas da matriz extracelular). Os pólipos mostraram aumento significante da área linfática total, enquanto o número de vasos (sanguíneos e linfáticos) e a área vascular sanguínea não diferiram significativamente das tonsilas controles. Raras células endoteliais expressaram Ki-67. Nos pólipos, pela primeira vez foi demonstrada a presença de VEAs, as quais foram identificadas em meio ao tecido linfóide. A quantidade deste último correlacionou-se positivamente com a densidade destas estruturas. Os pólipos também apresentaram menor quantidade de fibronectina e colágenos I e III, os quais estavam distribuídos de forma desorganizada. A expressão de tenascina-C foi pouco frequente nos pólipos e nas tonsilas controles. Concluindo, os pólipos tonsilares são compostos por tecido conjuntivo desorganizado e canais linfáticos dilatados, que podem ser consideradas proliferações hamartomatosas. Todavia, o componente linfóide possivelmente é reacional, devido a sua relação com as VEA. O fenótipo altamente diferenciado das VEAs e sua biologia complexa não são condizentes com natureza hamartomatosa / Abstract: Tonsillar polyps are nonneoplastic lesions usually composed of a variable amounts of lymphoid, vascular and connective tissues. All are generally assumed to be hamartomatous proliferations but the profile of vascular and connective components has yet to be explored. The vascular system of the tonsils is complex and includes highly specialized structures (i.e. high endothelial venules -HEVs) involved in lymphocyte homing into lymphoid tissues. In 14 tonsillar polyps and 26 control tonsils an immunohistochemical study was performed using CD34 (for blood vessels and HEVs), CD105 (for HEVs), D2-40 (for lymphatic vessels), Ki-67 (for proliferating index), collagens I and III, fibronectin and tenascin-C (for proteins of the extracellular matrix). The polyps showed increased total lymphatic area, whereas number of vessels (sanguineous and lymphatic) and blood vascular area did not differ significantly from those of control tonsils. Rare Ki-67+ endothelial cells were found. In the polyps, HEV was encountered amid lymphoid tissue and its amount correlated positively with the HEV density. The polyps also presented lesser amounts of fibronectin and collagens I and III which were distributed in a disorganized fashion. Tenascin-C expression was uncommon in the polyps and control tonsils. In conclusion, the tonsillar polyps are composed of disorganized connective tissue and lymphatic channels which can be considered hamartomatous proliferations. However, the lymphoid component is possibly reactive due to its relationship with the HEVs. The highly differentiated phenotype of the HEVs and its complex biology are not in agreement with what would be expected for a component of hamartomatous nature / Doutorado / Anatomia Patologica / Doutor em Ciências Médicas