Which lesions are at higher risk of developing colorectal carcinomas: superficially elevated serrated lesions or depressed lesions? / Quais lesões apresentam maior risco de evolução para carcinomas colorretais: as serrilhadas superficialmente elevadas ou as deprimidas?

ABSTRACT BACKGROUND: There are lesions that are still being missed in colonoscopy. Many of those could be superficially elevated serrated lesions or depressed ones. AIMS: The aim of this study was to compare the histopathological characteristics of these lesions and their risks for submucosal carcinoma. METHODS: This is a retrospective, cross-sectional, and observational study comparing 217 superficially elevated serrated lesions larger than 5 mm resected by colonoscopies (G1) with 558 depressed lesions (G2). RESULTS: In G1, 217 lesions were found in 12,653 (1.7%) colonoscopies; in G2, 558 lesions were found in 36,174 (1.5%) colonoscopies. In G1, 63.4% were women and in G2, there was no gender predominance. The average size of G1 was 16.2 mm and G2 was 9.2 mm (p<0.001). G1 predominated on the proximal colon and G2 on the distal and rectum (p<0.001). In G1, there were 214 (98.6%) low-grade intramucosal neoplasia and 3 (1.4%) high-grade intramucosal neoplasia. Excluding 126 hyperplastic polyps and considering 91 sessile serrated adenomas in G1, we observed 88 (96.7%) low-grade intramucosal neoplasia and 3 (3.3%) high-grade intramucosal neoplasia; in G2, we observed 417 (74.7%) low-grade intramucosal neoplasia, 113 (20.3%) high-grade intramucosal neoplasia, and 28 (5.0%) submucosal adenocarcinomas (p<0.001). CONCLUSION: Depressed lesions significantly had more high-grade intramucosal neoplasia and more invasive carcinomas in the submucosal layer than superficially elevated serrated lesions and more than superficially elevated sessile serrated adenomas.

RESUMO RACIONAL: Há ainda lesões que podem ser perdidas nas colonoscopias. Muitas delas poderiam ser serrilhadas superficialmente elevadas ou deprimidas. OBJETIVO: Comparar as características histopatológicas destas lesões e seus riscos para carcinoma invasivo para a submucosa. MÉTODO: Estudo retrospectivo, transversal, observacional comparando 217 lesões serrilhadas superficialmente elevadas com mais de 5 mm e ressecadas por colonoscopias (G1) com 558 lesões deprimidas (G2). RESULTADOS: As 217 lesões do G1 foram encontradas em 12.653 colonoscopias (1,7%) enquanto as 558 do G2 ocorreram dentre 36.174 colonoscopias (1,5%). No G1, 63,4% eram mulheres e no G2 não houve predominância de gênero. O tamanho médio foi no G1, 16,2 mm e no G2, 9,2 mm (p<0,001). G1 predominaram no cólon proximal e G2, no distal e reto (p<0,001). No G1, ocorreram 214 (98,6%) neoplasias mucosas de baixo grau e três de alto grau (1,4%). Excluídos 126 pólipos hiperplásicos e considerados os 91 adenomas sésseis serrilhados, no G1 observou- se 88 (96,7%) neoplasias mucosas de baixo grau e três (3,3%) de alto grau, e no G2, 417 (74,7%) neoplasias mucosas de baixo grau 113 (20,3%) de alto grau e 28 (5,0%) adenocarcinomas invadindo a submucosa (p<0,001). CONCLUSÕES: As lesões deprimidas apresentaram significativamente mais neoplasias mucosas de alto grau e carcinomas invasivos para a submucosa do que as serrilhadas superficialmente elevadas e mais do que os adenomas sésseis serrilhados superficialmente elevados.

Pre-malignant signs of gastric MALT lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma is the most common type of extra-nodal non-Hodgkin lymphoma, which mostly involves the stomach. The clinical suspicion and diagnosis are often challenging because of the lack of specific symptoms and conventional endoscopic findings. Three magnifying endoscopic signs of the gastric mucosa have been described as highly specific to the diagnosis of MALT lymphoma, such as (i) tree-like appearance of the microvessels; (ii) non-structural area; and (iii) ballooning crypt pattern. We report the case of a middle-aged woman in which these signs appeared chronologically over a period of 2 years, showing the association of the sequence of the endoscopic findings and the final histological diagnosis of gastric MALT lymphoma.

A rare case of recurrent acute pancreatitis after EUS-FNA in a patient with pancreatic intraepithelial neoplasia type 2 / Un raro caso de pancreatitis aguda recurrente después de EUS-FNA en un paciente con neoplasia intraepitelial tipo 2

Pancreatic intraepithelial neoplasia (PanIN) is considered a pre-malignant lesion difficult to identify by imaging methods. EUS- FNA is an effective technique to obtain material for histopathological study of pancreatic cystic tumors, but it is not free of adverse events. We report a case of a 56 years old patient, with chronic abdominal pain (early 1994). MRI showed pancreatic cystic images. The etiologic diagnosis was doubtful and EUS-FNA was performed. Immediately after a FNA, patient had an episode of acute pancreatitis, requiring hospitalization. During one year after FNA he had five episodes of AP. A new EUS suspected of PanIN, which was confirmed by surgery. After surgery the patient is well and has no more episodes of AP. Although the risk of AP, EUS-FNA should be performed to determine the best treatment for these patients with chronic abdominal pain who have cystic changes of pancreatic gland.

La neoplasia intraepithelial pancreática (PanIN) es considerada una lesión premaligna con dificultad diagnostica mediante métodos imagenlógicos. La EUS-FNA es una técnica efectiva para obtener material para el estudio histopatológico de tumores quísticos pancreáticos, pero no está libre de efectos adversos. Nosotros reportamos un caso de un paciente de 56 años de edad, con dolor abdominal cronico (desde 1994). En la resonancia abdominal se observó un quiste pancreático. El diagnostico etiológico fue dudoso y EUS-FNA fue realizada, después de la cual el paciente presento un cuadro de pancreatitis, requiriendo hospitalización. Durante el periodo de un año posterior a la FNA, éste presento cinco episodios de pancreatitis aguda. Un nuevo estudio ecoendoscopico dio la sospecha de PanIN, la cual se confirmó con la realización de la cirugía. Después de la cirugía quedo asintomático y sin presentar nuevos episodios de pancreatitis aguda hasta el momento. Aunque exista riego de pancreatitis aguda, la EUS-FNA debe realizarse para determinar el mejor tratamiento para pacientes con dolor abdominal crónico que tienen cambios quísticos de la glándula pancreática.

Comparative analysis of endoscopic and histopathological features of superficial elevated lesions resected by endoscopic mucosal resection in the distal and proximal colon / Análise comparativa dos aspectos endoscópicos e histopatológicos das lesões superficialmente elevadas ressecadas por mucosectomias no cólon distal e proximal

ABSTRACT Objective: to compare endoscopic and histopathologic features of superficial, elevated lesions with one or more centimeters in diameter, diagnosed by videocolonoscopy on the distal and proximal colon, and subjected to mucosal resection. Methods: we conducted a retrospective, cross-sectional, observational study involving 8,075 videocolonoscopies. From this total, we evaluated 166 mucosectomies in 145 patients with superficial, elevated lesions with a diameter equal to or greater than 1cm. Results: the lesion prevalence was lower in G1 than in G2 (34.9% vs. 65%). The mean age, gender distribution and size (1.9cm in G1 versus 2.0cm in G2, p=0.921) were similar. There was no difference of mucosal surfaces in relation to the location (p=0.575). Considering Intraepithelial neoplasias, both the low grade, high grade (including carcinomas) and hyperplasic ones showedd no difference (p=0.527), nor did the neoplastic lesions when divided into serrated and non-serrated (p=0.124). Excluding 13 hyperplastic lesions and two carcinomas, 124 (82.1%) were non-serrated and 27 (17.9%), serrated. Conclusion: were found no significant differences between endoscopic and histopathological aspects of superficial, elevated lesions of 1cm or more in diameter in distal colon compared with the proximal, when resected by mucosectomy. Although not significant, there was a tendency of association between the location of the lesion and the presence of serrated features.

RESUMO Objetivo: comparar aspectos endoscópicos e histopatológicos de lesões superficialmente elevadas, com um ou mais centímetros de diâmetro, diagnosticadas por videocolonoscopias e ressecadas por mucosectomias do cólon distal com as do cólon proximal. Métodos: estudo foi retrospectivo, transversal, observacional, envolvendo 8075 videocolonoscopias. Avaliou-se 166 mucosectomias em 145 pacientes com lesões superficialmente elevadas com diâmetro igual ou maior do que 1cm. Resultados: a prevalência de lesões foi menor no G1 do que no G2 (34,9% x 65%). A média de idade, a distribuição por sexo e o tamanho (1,9cm no G1 e 2cm no G2, p=0,921) foram semelhantes. Não houve diferenças das superfícies em relação à localização (p=0,575). Considerando neoplasia intraepitelial de baixo grau, neoplasia intraepitelial de alto grau (incluindo carcinomas) e hiperplásicas, não houve diferença (p=0,527), assim como quando foram divididas as lesões neoplásicas em serrilhadas e não serrilhadas (p=0,124). Excluindo-se 13 lesões hiperplásicas e duas com carcinomas, 124 (82,1%) foram não serrilhadas e 27 (17,9%) serrilhadas. Conclusão: não foram observadas diferenças significativas entre os aspectos endoscópicos e os histopatológicos das lesões superficialmente elevadas, com 1cm ou mais de diâmetro, ressecadas por mucosectomia do cólon distal em relação ao proximal. Embora não significante, há tendência à associação entre a localização da lesão e a presença de características serrilhadas.

Endoscopic ultrasound-guided biopsies for mediastinal lesions and lymph node diagnosis and staging

OBJECTIVES: To disseminate transesophageal ultrasound-guided fine needle aspiration (EUS-FNA) as an alternative to investigate mediastinal tumoral lesions because it is an underused modality that has been available in Brazil for more than 15 years. METHODS: Descriptive analysis of a single endoscopy service's experience since 1997 in the accomplishment of EUSFNA for mediastinal staging of previously known malignancies (Group 1) or diagnostic definition of suspect lymph nodes and masses (Group 2). RESULTS: EUS-FNA was performed in 51 patients between 26 and 87 years of age. The diameter of the lesions ranged between 1.1 and 9.8 cm (mean 3.9 cm). Their location corresponded to the following stations: higher paratracheal (4 cases), lower paratracheal (7), aortic window (12), para-aortic (6), subcarinal (9), paraesophageal (8), and hilar (5). In Group 1, 17 patients had previously diagnosed primary lung (9), breast (4), kidney (2), colon (1), and bladder (1) cancer. Fifteen of these punctures were positive for malignity. Two others were later submitted to mediastinoscopy, which identified metastases not detected by EUS-FNA. Group 2 comprised 34 patients. Among these patients, EUS-FNA diagnosed 22 neoplasms, five cases of tuberculosis and two duplication cysts. Cytology was inconclusive or without a specific diagnosis in five other cases. Mediastinoscopy identified two undiagnosed cases of oat-cell carcinoma, one lymphoma and one cryptococcosis, and confirmed one reactive lymphadenitis. There were no complications related to the method. CONCLUSIONS: EUS-FNA obviated the need for surgical procedures in 86.3 percent of cases. Therefore, oncologists, pulmonologists, and thoracic surgeons should always remember the technique's potential and availability.

Estudo prospectivo e comparativo do escovado obtido pela CPER à ecoendoscopia associada à punção aspirativa com agulha fina (EE-PAAF) no diagnóstico diferencial das estenoses biliares / Prospective comparative study of ERCP brush cytology and EUS-FNA for the diferential diagnosis of biliary strictures

OBJETIVO: Avaliar o desempenho diagnóstico da citologia obtida pela CPER, aquele obtido pela EE-PAAF e a concordância entre patologistas gerais (PG) e especialistas (PE) em pacientes com estenose biliar. MÉTODOS: Incluímos pacientes com estenose biliar identificados pela CPER. A EE-PAAF foi realizada apenas em áreas com efeito de massa ou da parede espessada do ducto biliar. O padrão-ouro foi a cirurgia, histologia e/ou o seguimento. As amostras teciduais foram consideradas: malignas, suspeitas, atípicas, insuficientes ou benignas. Os espécimes obtidos por cada método foi interpretado (cego) por um PG e outro PE. RESULTADO: 46 pacientes foram incluídos (37 malignos e 9 benignos). O diagnóstico final foi de tumor pancreático (26), biliar (11), pancreatite crônica (8) e estenose inflamatória do ducto biliar (1). Sensibilidade e acurácia da CPER foram 43,2 por cento e 52,2 por cento para o PG e 51,4 por cento e 58,7 por cento para o PE. Sensibilidade e acurácia da EE-PAAF foi 52,8 por cento e 58,5 por cento para o PG e 69,4 por cento e 73,2 por cento para o PE. A combinação entre a CPER e EE-PAAF demonstrou maior sensibilidade e acurácia para ambos PG (64,9 por cento e 69,6 por cento) e PE (83,8 por cento e 84,8 por cento), respectivamente. CONCLUSÃO: A citologia obtida pelo escovado da via biliar durante a CPER e as amostras teciduais colhidas pela EE-PAAF tem rendimento semelhante para o diagnóstico das estenoses biliares. No entanto, a combinação dos métodos resulta em uma maior acurácia. Além disso, espera-se que a interpretação das amostras ocorra com maior precisão pelo PE se comparado ao PG.

OBJECTIVE: To evaluate and to compare the diagnostic yield of ERCP brush cytology (ERCP) and EUS-FNA in patients with biliary strictures and evaluates the agreement between general pathologists (GP) and expert GI pathologists (GIP) in the final diagnosis of biliary strictures. METHODS: Patients with biliary strictures documented by ERCP were included. Brush cytology was performed and during EUS, only visible mass lesions or localized bile duct wall thickening were aspirated. The gold standard method for diagnosis was surgical histology and/or follow-up. Tissue sampling results were: malignant, suspicious, atypical, insufficiently or benign. Specimens were interpreted by GP and GIP, blinded for prior tests results. RESULTS: 46 patients were included. Final diagnosis was malignancy in 37 (26 pancreatic - 11 biliary) and benign in 9 (8 chronic pancreatitis - 1 common bile duct inflammatory stricture). Sensitivity and accuracy for ERCP brush cytology were 43.2 percent and 52.2 percent for GP and 51.4 percent and 58.7 percent for GIP. Sensitivity and accuracy for EUS-FNA were 52.8 percent and 58.5 percent, respectively for GP and 69.4 percent e 73.2 percent for GIP. In comparison, the combination of brush cytology and EUS-FNA demonstrated higher sensitivity and accuracy for both GP (64.9 percent and 69.6 percent, respectively) and GIP (83.8 percent and 84.8 percent, respectively) and improved agreement with final diagnosis for both (mostly for GIP). CONCLUSION: Both, ERCP brush cytology and EUS-FNA has a similar yield for the diagnosis of biliary strictures. However, the combination of these methods results in an improved diagnostic accuracy. In addition, GIP might be expected to interpret specimens with greater accuracy than GP.

Endoscopic ultrasound guided fine-needle aspiration core biopsy: comparison between an automatic biopsy device and two conventional needle systems / Biopsia tecidual con aguja fina guiada por ultrasonido endoscópico: comparación entre un dispositivo automático de la biopsia y dos sistemas de agujas convencionales

BACKGROUND: endoscopic ultrasound guided fine-needle aspiration (EUS-FNA) allows cytologic and/or histologic diagnosis of lesions within or adjacent to the gastrointestinal tract. However, the amount of tissue obtained with a regular 22 gauge needle is not always satisfactory. With the development of a needle XNA-10J-KB (Shot-Gun) that resembles the automatic liver biopsy needle, it is expected that significant samples be obtained more frequently (core biopsy), optimizing histological analysis. OBJECTIVE: to compare samples obtained with EUS-FNA using 3 different needle systems: GIP, NA-10J-1 and Shot-Gun. METHODS: 19 patients underwent EUS-FNA for diagnosis (5) or tumor staging (14). Mean age was 58.9 years (range 27-82), being 50% men. All patients were submitted to EUS-FNA with the 3 needle models. The Shot-Gun model was "shot" when its tip was near the target inside the lesion, followed by aspiration. Samples were submitted for cytologic and histologic examination. RESULTS: mean lesion size was 3.0 cm (range 0.8-5.5 cm). Final diagnoses were made after surgery or intra-operative biopsy: 13 pancreatic tumors (12 adenocarcinomas and 1 neuroendocrine tumor), 4 chronic pancreatitis, 1 acute pancreatitis, and 1 cholangiocarcinoma. Specimens adequate for cytologic diagnosis were obtained in 13/19 (68. 4%) patients using GIP model, in 14/19 (73.7%) with NA10J-1 model, and in 17/19 (89.5%) with ShotGun, model (p=0.039). Histologic analysis was possible in 10/19 (52.6%) patients using the GIP model, in 14/19 (73.7%) with NA10J-1, and in 17/19 (89.5%) with Shot-Gun, model (p=0.005). Adequate samples for cytologic or histologic assessment in 16/19 (84.2%) patients using the GIP model, in 17/19 (89.5%) with NA10J-1, and in 18/19 (94.7%) with Shot-Gun, model (p=0.223). In two cases biopsies were negative due to very hard tumors. CONCLUSION: the Shot-Gun needle obtained better samples for histological diagnosis than NA10J-1 needle and GIP.

Introducción: la ecografía endoscópica asociada a la punción guiada con aguja fina (EUS-FNA) permite el examen citológico y/o diagnóstico histológico de las lesiones dentro o junto al tracto gastrointestinal. Sin embargo, la cantidad de tejido obtenido con una aguja de calibre 22 G no es siempre satisfactoria. Con el desarrollo de una aguja XNA-10J-KB (Shot-Gun®) que seasemeja a la biopsia hepática automática como una aguja especial, se espera que se obtengan muestras importantes con más frecuencia permitindo optimizar el mejor análisis histopatológico. Objetivo: comparar lasmuestras obtenidas con EUS-FNA con 3 diferentes sistemas de aguja: GIP ®, NA-10J-1 ® y Shot-Gun ®. Métodos: 19 pacientes fueron sometidos a EUS-FNApara el diagnóstico (5) para el análisis de las etapas del tumor (14). La edad media fue de 58,9 años (rango 27-82), siendo el 50% hombres. Todos los pacientes fueron sometidos a EUS-FNA con los 3 modelos de aguja. Del Shot-Gun ® fue "disparada" su punta cuandoestaba cerca de la meta en el interior de la lesión, seguida de aspiración. Las muestras se sometieron a examencitológico e histológico. Resultados: el promedio de tamaño de la lesión fue de 3,0 cm (rango 0,8-5,5 cm). Los diagnósticos definitivos fueron hechos después de la cirugía o la biopsia intra-operatoria: 13 tumores de páncreas (12 adenocarcinomas y 1 tumor neuroendócrino), 4 de pancreatitis crónica, 1 de pancreatitis aguda, y 1 de colangiocarcinoma. Las muestras adecuadas para el diagnóstico citológico se obtuvieron en 13/19 (68,4%) pacientes que utilizan GIP ®, en 14/19 (73,7%) con NA10J-1 ®, y en 17/19 (89,5%) con Shot-Gun® (p = 0,039). El análisis histológico fue posible en 10/19 (52,6%) pacientes que utilizan elGIP®, en 14/19 (73,7%) con NA10J-1 ®, y en 17/19 (89,5%) con Shot-Gun® (p = 0,005). Suficientes muestras para citológico o histológico de evaluación en16/19 (84,2%) pacientes que utilizan el modelo GIP ®, en 17/19 (89,5%) con NA10J-1 ®...

Hand-sewn and stapled esophageal anastomosis: experimental study in dogs

PURPOSE: To compare experimentally, the healing of cervical oesophageal anastomoses performed either with stapler or 2-layer hand-sewn sutures. METHODS: Thirty six dogs were randomised to two groups: stapled anastomoses (n =18); hand-sewn anastomoses (n =18). Each group was divided into three subgroups, corresponding to the day of sacrifice (3rd, 7th and 14th postoperative day). Healing was assessed by: a) anatopathology b) anastomotic resistance to bursting pressure test; c) quantification of hidroxyproline. RESULTS: Group 1 heal by second intention, group 2 showed a healing by first intention. Bursting pressure was similar between groups at day 3, though group 1 animais showed it significanfy higher at day 7and day 14 compared with group 2. Statiscally, there were no interaction between the day of sacrifice and groups, as well as there was no difference among the dates of observation regarding the results of hidroxyproline. CONCLUSIONS: a) mechanical suture is more resistant than hand-sewn; b) In stapler anastomoses, healing was as secondary union, whereas in hand-sewn anastomoses, healing was by first intention; c) no correlation was found in the results of bursting pressure and hidroxyproline quantification.

Transformação sarcomatosa em meningeoma / Sarcoma arising in meningioma

Os autores relatam o caso de paciente de 40 anos, raça amarela, sexo masculino, que apresentou história arrastada de déficit de força em hemicorpo direito com predomínio em membro inferior direito, cujo diagnóstico de imagem (tomografia computadorizada de crânio e ressonância magnética) revelou tratar-se de neoplasia parassagital esquerda com características semelhantes às de um meningeoma. Foi submetido à cirurgia com ressecção radical, incluindo o seio sagitalinvadido, com boa evolução no pós-operatório. O diagnóstico anatomopatológico foi de meningeoma com transformação sarcomatosa (meningeossarcoma/sarcoma meníngeo). Foi submetido à radioterapia e o seguimento de 8 meses não evidenciou recidiva. A transformação sarcomatosa é rara e infere um prognóstico reservado. Os autores discutem a doença e procuram identificar semelhanças e diferenças clínicas e radiológicas com as principais neoplasias do sistema nervoso central derivadas de células meningoteliais e de hemangiopericitos.

Malignancy in meningiomas is not frequent, however on rare occasions a benign meningioma may change into a tumor with features of malignancy or even sarcomatous cells. A case of sarcoma arising in a meningioma in a 40 year-old man is reported. Despite of the poor prognosis after thesurgical and radiotherapic treatment, this patient goes on without recurrence for eight months after surgery and radiotherapy. The pathological and radiological features as well as a differentialdiagnosis of this disease are discussed by the authors based on literature review.

Valor diagnóstico do conteúdo celular de DNA (ploidia) e da atividade proliferativa tumoral no câncer colorretal: comparaçäo com as variáveis clínico-patológicas convencionais / Prognostic value of cellular content of DNA (Ploidy) and proliferative activity tumor in colorectal cancer: comparison with conventional clinical pathologic variables

O presente estudo objetivou analisar os resultados e o valor prognóstico da ploidia do DNA e da atividade proliferativa tumoral (AP) no câncer colorretal (CCR) pela técnica da citometria digital de DNA (CD) através da comparaçäo entre estas duas variáveis e variáveis clínico-patológicas convencionais. Foram estudados prospectivamente 50 doentes submetidos a tratamento cirúrgico do CCR. As variáveis clínico-patológicas foram: sexo, idade, localizaçäo do tumor, tipo histológico, grau de diferenciaçäo, margem invasora, acometimento linfonodal e estadiamento (Dukes e Jass). Em todos os casos foi possível determinar a ploidia do DNA e a AP.A frequência de aneuploidia foi de 68 por cento e a AP tumoral média foi de 12,34 por cento. A correlaçäo entre as variáveis estudadas e a sobrevida foi realizada por análise uni e multivariada. Conclui-se que a CD é eficaz na determinaçäo do conteúdo celular de DNA e da AP tumoral no CCR. A ploidia do DNA e a AP näo estäo associadas às variáveis Clínico-patológicas estudadas. Näo foi possível demonstrar valor prognóstico da ploidia do DNA ou da AP tumoral. A padronizaçäo das técnicas de citometria e da estimativa do valor prognóstico constituem medidas necessárias à produçäo de resultados mais precisos sobre o papel da ploidia e da AP tumoral no prognóstico do CCR

Carcinoma epidermóide de esôfago induzido pela dietilnitrosamina (DEN) / The epidermoid carcinoma of the esophagus induced by diethylnitrosamine

O objetivo desta pesquisa foi verificar a ocorrência de carcinoma epidermóide de esôfago induzido pela DEN, em ratos WISTAR. A DEN foi administrada a dois grupos de 20 animais (peso 250-300 grs.), na água de beber (10 mg/Kg/pêso) durante 72 hs/semana, respectivamente por 120 dias e 200 dias (T120 e T200). Outros 10 animais ingerindo apenas água serviram de controles. Os 50 animais foram sacrificados e seus esôfagos estudados macro e microscopicamente. No grupo controle nao ocorreram carcinomas, nem lesoes pré-neoplásicas. Nos grupos T120 e T200 ocorreram, respectivamente, 47 e 58 carcinomas, "in situ"; 1 e 20 carcinomas submucosos (p<0,05); 4 e 17 carcinomas micro-invasivos (p<0,05); 4 e 11 carcinomas avançados (p<0,05); 1 e 1 hiperplasias benignas. Além disso, foram encontrados carcinomas pulmonares e hepáticos. A maioria das lesoes macroscópicas avançadas no grupo T200 foram polipóides, exofiticas e nao invasivas à microscopia. Este estudo permite concluir que a DEN é efetiva na carcinogênese do esôfago do rato WISTAR e que as lesoes sao dose dependentes.