Papillary Adenocarcinoma of the descending colon in a dog: case report / Adenocarcinoma papilífero em cólon descendente de cão: relato de caso

The aim of this report was to describe the clinical findings and therapeutic management of a case of papillary adenocarcinoma of the descending colon in a Beagle. The patient presented soft stools, haematochezia, tenesmus, and dyschezia. Clinical examination revealed alterations on the ultrasonographic features of the descending colon suggestive of colitis and neoplasia. Following local mass resection, histopathology analysis revealed mild lymphoplasmocytic enteritis and papillary adenocarcinoma of the colon. Enterectomy for tumoral resection and biopsy of locoregional lymph nodes were carried out. Subsequent to the surgical procedure, it was possible to confirm the previous diagnosis and the tumor was classified as intestinal intraluminal papillary adenocarcinoma, with incomplete surgical margins. Adjuvant chemotherapy was performed using carboplatin, cyclophosphamide, and piroxicam, leading to remission of clinical signs and absence of any clinical or imaging alterations compatible with the patient's previous clinical condition.(AU)

O objetivo desse relato de caso foi descrever os achados clínicos e manejo terapêutico de um caso de adenocarcinoma papilífero do cólon descendente em um Beagle. O paciente apresentou fezes amolecidas, hematoquesia, tenesmo e disquesia. Exame clínico revelou alteração de achados ultrassonográficos do cólon descendente sugerindo colite e neoplasia. Após ressecção de massa local, análise histopatológica revelou enterite linfmoplasmocito leve e adenocarcinoma papilar do cólon. Enterectomia para ressecção tumoral e biopsia das lesões locais e tumores linfonodais foram realizadas. Após procedimento cirúrgico foi possível confirmar o diagnóstico prévio e o tumor foi classificado como adenocarcinoma papilar intraluminal intestinal, com margens cirúrgicas incompletas. Quimioterapia adjuvante foi realizada utilizando carboplatina, ciclofosfamida e piroxano, levando a remissão de sinais clínicos e ausência de alterações de imagem compatíveis com situação clínica prévia do paciente.(AU)

Additional Polyp Detection Rate Using Colonoscopic Retroflexion in Right Colon / 대한소화기학회지

BACKGROUND/AIMS: There have been several studies showing that retroflexion (RF) in the right colon (RC) could reduce the polyp miss rate of proximal colon during colonoscopy. This study was conducted to evaluate the additional benefit of RF technique in the RC. METHODS: Patients who underwent colonoscopy from May 2008 to April 2011 were enrolled in the study. Data were obtained by retrospectively reviewing the medical records. RF was attempted in every patients undergoing colonoscopy since May 2008 except in cases of small RC vault, co-morbidity, severe diverticulosis, failed RF despite two trials, complaints of severe abdominal pain, or time burden. At first, RC was examined under direct vision. It was then examined by RF to detect missed polyps during the initial observation. Finally, the RC was re-examined with direct view. RESULTS: The cumulative RF success rate in the RC was 78.84% (1,805 of 2,319). The RF success rate increased with the number of cases (50% at 160 cases, 70% at 400 cases, and reached near 90% over 1,000 cases). Few polyps (4.88%) were detected only with RF and the additional adenoma detection rate was 3.32%. The additional polyp/adenoma detection rates were higher in the old age group (p<0.01). There were no RF associated perforation or severe complication. CONCLUSIONS: Using RF examination, additional 4.88% of polyps could be detected in the RC. This technique could be a useful and safe method to detect hidden polyp during colonoscopy.

Site-specific Colorectal Cancer; How Is It Different? / 대한소화기학회지

One of the most critical characteristics of colorectal cancer (CRC) is the difference between proximal (right-sided colon cancer, RCC) and distal (left-sided colon cancer, LCC) disease. The recent CRC studies showed the unique characteristics of RCC; RCCs were more prevalent in women than men and old patients, and the age difference between RCC and LCC was more apparent in women. Moreover, relatively poor protection against RCC by colonoscopy is a clearly hot issue for alarm. Thus, the left and right colon have been considered as dichotomous or even different organs in the view of molecular, histopathological, epidemiologic and clinical bases for over three decades. However, the evolutionary data suggesting linearity from the rectum to ascending colon beyond the simple right-left dichotomization in the views of cancer molecular features and site-specific clinicopathological differences, support the need for a paradigm shift to the colorectal continuum model rather than the traditional two-colon concept. This new multi-segmental or colorectal continuum hypothesis would provide both the better understanding of the complex etiology of colorectal carcinogenesis and the tailored preventive and therapeutic strategies for CRC including individualized CRC screening programs.

Increased Immunoendocrine Cells in Intestinal Mucosa of Postinfectious Irritable Bowel Syndrome Patients 3 Years after Acute Shigella Infection: An Observation in a Small Case Control Study

PURPOSE: Postinfectiously irritable bowel syndrome (PI-IBS) develops in 3-30% of individuals with bacterial gastroenteritis. Recent studies demonstrated increases in inflammatory components in gut mucosa of PI-IBS patients even after complete resolution of infection. We aimed to investigate histological changes in colon and rectum of PI-IBS subjects after long term period of infection. MATERIALS AND METHODS: We recruited PI-IBS subjects who had been diagnosed IBS after complete resolution of enteritis caused by shigellosis outbreak 3 years earlier. We compared unmatched four groups, PI-IBS (n = 4), non PI-IBS (n = 7), D-IBS (n = 7, diarrhea predominant type) and healthy controls (n = 10). All of them underwent colonoscopic biopsy at three areas, including descending colon (DC), sigmoid colon (SC) and rectum, which were assessed for 5-hydroxytryptamine (5-HT)/peptide YY (PYY)-containing enterochromaffin (EC) cell, intraepithelial (IEL) and lamina propria T lymphocyte (CD3), CD8 lymphocytes, mast cells and CD68/calprotectin+ macrophages. RESULTS: All subjects had no structural or gross abnormalities at colonoscopy. In PI-IBS, 5-HT containing EC cells, PYY containing EC cells, IELs, CD3 lymphocytes, CD8 lymphocytes, mast cells, and CD68 + macrophages were increased compared to control (p < 0.05). In D-IBS, PYY containing EC cells, IELs, and CD3 lymphocytes were increased compared to control (p < 0.05). In PI-IBS, 5-HT containing EC cells tended to increase and PYY containing EC cells, CD8 lymphocytes, mast cells, and CD68+ macrophages were increased compared to non PI-IBS (p < 0.05). Calprotectin + marcrophages were decreased in PI-IBS, non PI-IBS and IBS compared to control. CONCLUSION: The immunoendocrine cells were sporadically increased in PI-IBS, non PI-IBS and D-IBS compared with control. Our findings in a very small number of patients suggest that mucosal inflammation may play a role in long-term PI-IBS, and that other sub-groups of IBS and larger scale studies are needed to confirm this observation.

Granular Cell Tumor of the Descending Colon Treated by Endoscopic Mucosal Resection: A Case Report and Review of the Literature

Although colorectal granular cell tumors (GCTs) are rare, their incidental finding has increased as the use of diagnostic colonoscopy has become more common. Here we describe the case of a 41-yr-old man with a GCT in the descending colon that was detected after a screening colonoscopy. Endoscopic examination revealed a yellowish submucosal tumor, 13x12 mm in diameter, in the descending colon. Endoscopic mucosal resection (EMR) followed by histological examination revealed that the tumor was composed of plump histiocyte-like cells with an abundant granular eosinophilic cytoplasm and small round nuclei. The tumor cells expressed S-100 protein and stained with periodic acid-Schiff, but were negative for desmin and cytokeratin. The resected tumor was diagnosed as a GCT. Colonoscopists should consider the possibility of GCT in the differential diagnosis of yellowish submucosal tumors of the colon. In such patients, EMR seems to be a feasible and safe approach for diagnosis and treatment.

Alterations of the myenteric plexus of the ileum and the descending colon caused by Toxoplasma gondii (genotype III) / Alterações do plexo mientérico do íleo e cólon descendente causadas por Toxoplasma gondii (genótipo III)

Alterations caused by a genotype III strain of Toxoplasma gondii were assessed with respect to the number and the morphometry of the myenteric neurons in the terminal ileum and the descending colon. Eighteen rats were divided into four groups: Acute Control Group (ACG, n=4); Acute Experimental Group (AEG, n=4); Chronic Control Group (CCG, n=5) and Chronic Experimental Group (CEG, n=5). NaCl solution was administered through gavage to the animals in the ACG and CCG. Toxoplasma gondii tachyzoites (10(4)) from a genotype III strain were orally administered to the AEG and CEG. Acute Groups were died after 24 hours, and the Chronic Groups after 30 days. Neuronal loss was not observed in both organs. The neurons atrophied in the terminal ileum as the opposite occurred with the neurons at the descending colon during the chronic phase of infection. In the terminal ileum, the neurons atrophied during the chronic phase of the infection as no alteration was found during the acute phase. For the descending colon, the neurons became hypertrophic during the chronic infection in opposition to the atrophy found during the acute phase.

Objetivou-se avaliar as alterações causadas por uma cepa genótipo III de Toxoplasma gondii, sobre o número e a morfometria de neurônios mientéricos, do íleo terminal e do cólon descendente. Dividiu-se dezoitos ratos em quatro grupos: controle agudo (GCA, n=4), experimental agudo (GEA, n=4), controle crônico (GCC, n=5) e experimental crônico (GEC, n=5). Os animais do GCA e GCC receberam solução de NaCl por gavagem, e os animais do GEA e GEC 10(4) taquizoítos de uma cepa genótipo III de T. gondii por via oral. Os grupos agudos após 24 horas foram mortos e os crônicos após 30 dias. Observou-se que não houve perda neuronal em ambos os órgãos. No íleo terminal, os neurônios atrofiaram-se na fase crônica da infecção, enquanto nenhuma alteração ocorreu na fase aguda. Já no cólon descendente, os neurônios tornaram-se hipertróficos na fase crônica da infecção, em oposição à atrofia observada na fase aguda.

Histological study of the left colon of rats after extra-mucosal seromyotomy (continent valves): evaluation of colonic emptying / Estudo histológico do cólon esquerdo de ratos após a confecção de seromiotomias extra-mucosas (válvulas continentes): avaliação do grau de esvaziamento do conteúdo colônico

PURPOSE: To elaborate an animal model with the objective of studying the continence of the biological valves surgically performed in the left colon of rats. METHODS: Thirty four rats were operated on and divided into three groups (G). G1 (sham) animals which underwent laparotomy only; G2 (perineal amputation without valves): animals which underwent amputation of the anal sphincter complex combined with a perineal colostomy; G3 (abdominoperineal amputation combined with valves): animals which underwent abdominoperineal amputation combined with three, equidistant and circumferential (360(0)), extra-mucosal seromyotomies, of the descending colon, which were sutured to create biological valves combined with perineal colostomy. Animals were euthanized in the late postoperative period and surgical valves were saved for histopathological study. RESULTS: Surgical procedure provoked intestinal dilation, as well as segmented chambers along the descending colon. Retained fecalomas between the valves and proximal to them were also noted. Six rats died of intestinal obstruction due to fecal impaction at the surgical site. The sequence of events was: stasis, obstruction, distention, perforation, peritonitis and death. Histopathology showed inflammation due to foreign body type reaction around the sutured colon causing partial concentric stenosis, capable of interfering normal mechanical activity of the distal colon. This process resulted in retardation of the intestinal transit. CONCLUSION: Extra-mucosal seromyotomies, with seromuscular suture, can be used as an operative procedure capable of causing retardation in the intestinal transit of rats.

OBJETIVO: Modelo de experimentação, com confecção de válvulas biológicas no cólon esquerdo de ratos com o objetivo de estudar o grau de continência dessas válvulas. MÉTODOS: Trinta e quatro ratos foram operados e distribuidos em três grupos: G1 (grupo simulado) submetido apenas à laparotomia, G2 (grupo amputado sem válvula) submetido à amputação do conjunto esfincteral mais colostomia perineal e G3 (grupo amputado com válvula) submetido à amputação do conjunto esfincteral, confecção de três seromiotomias extra-mucosas, eqüidistantes e circunferenciais (360(0) - válvulas biológicas), no colon descendente mais colostomia perineal. No pós-operatório tardio, os animais dos três grupos foram submetidos à eutanásia para coleta da peça cirúrgica e estudo histopatológico das válvulas. RESULTADOS: Os resultados mostraram que o procedimento culminou em dilatação intestinal, confirmada pela formação de verdadeiras câmaras de segmentação e pela presença de fecalomas retidos entre as válvulas e cranialmente a elas. Seis ratos morreram em decorrência de obstrução intestinal por impacção de fezes no local operado, na seqüência: obstrução, estase, distensão, perfuração, peritonite e morte. As alterações histopatológicas confirmaram o processo inflamatório com reação do tipo corpo estranho, no perímetro do cólon suturado, proporcionando uma estenose parcial concêntrica, levando à alteração da atividade mecânica do cólon distal, resultando no retardo do trânsito intestinal. CONCLUSÃO: As seromiotomia extramucosas, com sutura seromuscular, podem ser utilizadas como técnica operatória para se obter retardo do trânsito intestinal em ratos.

Quantitative Study of the Myenteric Plexus of the Descending Colon of Young Rats Subjected to Intense Protein Deficiency / Estudio Cuantitativo del Plexo Mientérico del Colon Descendente de Ratas Jóvenes Sometidas a Intensa Deficiencia Proteica

We studied the effects of a severely hypoproteic diet on the quantitative aspects of the myenteric plexus of the descending colon of young rats. Eighteen rats were divided into two groups, one of them being fed with a chow having 26% protein (control) and the other with a chow having 4% protein, balanced for minerals and vitamins, during 12 weeks. The whole-mounts of the descending colon had their myenteric neurons stained either with Giemsa or NADPH diaphorase. The rats from the experimental group had deficits of body weight (54.23%) and area of the descending colon (48.14%); additionally, we observed that there was no alteration in the total number of neurons of the colon, but a decrease in the number of NADPH-diaphorase positive neurons (37.80%). The implications of these results concerning the priority that some cellular types may have when nutrients are less available are discussed.

Estudiamos los efectos crónicos de una dieta severamente hipoproteica sobre los aspectos cuantitativos del plexo mientérico del colon descendente de ratones jóvenes. 18 ratones fueron divididos en dos grupos, a uno de estos grupos se le dió ración con contenido proteico del 26% (control) y al otro, ración con contenido proteico del 4%. Se mantuvo el balance vitamínico y mineral, durante 12 semanas. Elaboramos los preparados de membrana del colon descendente y marcamos las neuronas del plexo mientérico con Giemsa y NADPH-diaforasa. Los ratones del grupo experimental presentaron déficit de peso corporal (54,23%) y del área del colon descendente (48,14%); además, observamos que no hubo alteración en el número total de neuronas en todo el colon; sin embargo, hubo una disminución en la marcación de neuronas NADPH-diaforasa positivas (37,80%). Los resultados son discutidos, respecto a la prioridad que ciertos tipos celulares pudiesen tener, con la menor disponibilidad de nutrientes.