Infra-anastomotic Innervation of Residual Aganglionic Distal Rectum After Pull-through Surgery for Hirschsprung Disease

BACKGROUND

Descending neurons are important for intestinal reflex activities, including the recto-anal inhibitory reflex involved in normal defecation. Pull-through surgery for Hirschsprung disease results in the anastomosis of ganglionic bowel to native aganglionic rectum just superior to the internal anal sphincter, which potentially could allow for physiologically significant infra-anastomotic innervation.

METHODS

The density and distribution of intramuscular neuronal nitric oxide synthase (nNOS)- and mucosal calretinin-immunoreactive nerves were evaluated proximal and distal to the anastomosis in redo resection specimens after pull-through surgery for Hirschsprung disease. The findings were compared with data collected from cadaveric controls with no history of dysmotility and the distal aganglionic segments of primary rectal resections from patients with Hirschsprung disease.

RESULTS

Native aganglionic rectum of Hirschsprung patients lacks the normal lush intramuscular nNOS- and mucosal calretinin-immunoreactive nerves present in normal bowel. In post-pull-through resection specimens obtained more than 7 months after pull-through surgery, nNOS- and calretinin-positive innervation is at least partially restored for variable distances up to 10 to 12 mm inferior to the anastomosis, respectively.

CONCLUSIONS

Innervation of infra-anastomotic muscularis propria and mucosa in the aganglionic distal rectum occurs to a variable degree after pull-through surgery for Hirschsprung disease and may contribute to individual differences in postoperative obstructive symptoms. Strategies to enhance infra-anastomotic innervation may improve clinical outcome.

Endoscopic, transanal, laparoscopic, and transabdominal management of rectal neuroendocrine tumors

Rectal neuroendocrine tumors (RNET) are rare tumors but their prevalence is constantly increasing due to a prolonged survival and rising incidence related to a growing number of colonoscopies and improved knowledge. Their main prognostic determinant is tumor stage. While most RNET are localized, their management should be tailored depending on the presence or absence of the factors predictive of lymph-node metastases including tumor size, endoscopic aspect, T stage, grade and lymphovascular invasion. Endoscopic ultrasonography is the most relevant technique for locoregional assessment. Low-risk RNET can be treated using advanced endoscopic resection techniques or transanal endoscopic microsurgery, in expert centers because they require technicity and experience. Conversely, radical surgery with lymphadenectomy should be proposed in the presence of any pejorative factor. The long-term evolution of RNET remains to be specified, and prospective studies should be conducted in order to determine the relevance of the current management strategies.

Appendicorectal fistula with a novel solution: First case report and review of the literature

Appendicorectal fistula can be a cause of chronic abdominal pain, forming years after an occult episode of appendicitis. It can be diagnosed with Colonoscopy and Magnetic Resonance Imaging, and successfully treated surgically with laparoscopic appendicectomy and stapled segmental cuff resection of the rectum.

Clinical features, treatment and outcomes of colorectal mucosa-associated lymphoid tissue (MALT) lymphoma: literature reviews published in English between 1993 and 2017

Background

Colorectal mucosa-associated lymphoid tissue (MALT) lymphoma (cMALToma) is rare and comprises only 2.5% of the MALT lymphomas. Its etiology and treatment have not been well established. The aim of this systematic literature review was to try to characterize cMALToma and analyze the risk factors for treatment failure with various therapeutic strategies.

Methods

We retrospectively reviewed 50 case reports from 1993 to 2017 through a PubMed search of English medical literature, describing cMALToma. We included 67 patients from previous case reports and we added 6 patients treated for cMALToma in our multicenter institutes. Risk factor analysis was done for treatment failure, defined as remission failure and recurrence.

Results

Of 73 patients diagnosed with cMALToma, tumors were located in 54 patients (74.0%) in the rectum, in 10 patients (13.6%) in the right colon, in 3 patients (4.1%) in the transverse colon, and in 6 patients (8.2%) in the sigmoid colon. In first-line treatment, patients achieved complete remission (CR) with surgery (18/19 cases), local resection (18/19 cases), chemotherapy (12/13 cases), radiation therapy (4/5 cases), antibiotics therapy including Helicobacter pylori eradication (12/15 cases), and no treatment (1/2 cases). Among these, eight cases (10.9%) needed second-line treatment, and there was overall remission failure in 3 cases (4.1%). Of the remaining 70 patients with CR, the tumor recurred in 5 patients (6.8%). The multivariable analysis showed that male sex, multiple tumors, and first-line treatment failure were significantly related to treatment failure (p=0.03, p=0.05, p=0.03, respectively).

Conclusion

CR of primary cMALToma was achieved using various therapeutic strategies. First-line treatment failure and multiple tumors were associated with treatment failure, although the numbers of cases that failed are too small to draw definitive conclusions.

A Multiple Dose Phase 1 Assessment of Rilpivirine Long Acting in a Model of Preexposure Prophylaxis Against HIV

The MWRI-01 study characterized the safety, acceptability, pharmacokinetic (PK), and pharmacodynamic (PD) profile of rilpivirine (RPV) long acting (LA) in a model of preexposure prophylaxis (PrEP). Prospective, open-label Phase 1 study. The safety and acceptability of three repeated doses of RPV LA were monitored. Blood, tissue (rectal, cervical, and vaginal), and biological fluids (vaginal and endocervical) were collected at baseline and at 1- to 2-month intervals throughout the study for PK and PD assessment. Eight women and four men received three intramuscular doses of 1,200 mg of RPV LA given 8 weeks apart. There were a total of 195 adverse events (AEs) reported, of which 138 (70.8%) were Grade 1 and 55 (28.2%) were Grade 2. The most common AE was injection site pain. Geometric mean (90% confidence interval) plasma RPV concentrations at 56 days after the first and third doses were 39 (33-45) ng/mL (female)/29 (17-40) ng/mL (male) and 59 (45-62) ng/mL (female)/40 (30-51) ng/mL (male), respectively. Exposure to RPV LA was associated with significant inhibition of HIV-1_BaL viral replication in the ex vivo rectal explant model (p < .0001) that persisted for up to 4 months after the third dose of RPV LA. In contrast, no viral suppression was seen in cervicovaginal tissue. Multiple dose administration of RPV LA was safe and well tolerated, and was associated with prolonged suppression of viral replication in rectal explant tissue.

Imaging features of Benign Perianal lesions

Magnetic resonance imaging provides detailed visualisation, identification and extent assessment of many anal disorders. While many studies are performed in the evaluation of malignant processes such as anorectal carcinoma, the primary focus of this pictorial review is benign lesions, which involve the anal canal and perianal spaces. This pictorial review will illustrate the MRI appearances of a variety of benign conditions, which predominantly affect the anal canal, including abscess, fistulae, lipomas, developmental cysts and inflammatory conditions. MRI aids in the identification and characterisation of these abnormalities, of coexisting complications and differentiation from other perineal abnormalities. This pictorial review highlights the spectrum of non-malignant processes involving the perianal region.

Detailed and applied anatomy for improved rectal cancer treatment

Rectal anatomy is one of the most challenging concepts of visceral anatomy, even though currently there are more than 23,000 papers indexed in PubMed regarding this topic. Nonetheless, even though there is a plethora of information meant to assist clinicians to achieve a better practice, there is no universal understanding of its complexity. This in turn increases the morbidity rates due to iatrogenic causes, as mistakes that could be avoided are repeated. For this reason, this review attempts to gather current knowledge regarding the detailed anatomy of the rectum and to organize and present it in a manner that focuses on its clinical implications, not only for the colorectal surgeon, but most importantly for all colorectal cancer-related specialties.

Remodeling of Rectal Innervation After Pullthrough Surgery for Hirschsprung Disease: Relevance to Criteria for the Determination of Retained Transition Zone

BACKGROUND

After pullthrough surgery for Hirschsprung disease (HSCR), Glut1-positive submucosal nerve hypertrophy is used to diagnose retained transition zone in the neorectum. We hypothesized that pelvic nerves, severed during pullthrough surgery, sprout into the neorectum to mimic transition zone.

METHODS

The density (nerves/100x field) and maximum diameter of Glut1-positive submucosal nerves were measured in biopsies and redo resections from 20 patients with post-pullthrough obstructive symptoms. Their original and/or redo resections excluded unequivocal features of transition zone (myenteric hypoganglionosis or partial circumferential aganglionosis) in 17. Postoperative values were compared with control data from 28 cadaveric and 6 surgical non-HSCR specimens, and 14 primary HSCR resections. When possible, nerves were tracked from attached native pelvic soft tissue or aganglionic rectal cuff into the pulled-through colon.

RESULTS

Glut1-positive submucosal nerves were not present in the 11 colons of non-HSCR infants less than 1 year of age, except sparsely in the rectum. In 17 older non-HSCR controls, occasional Glut1-positive nerves were observed in prerectal colon and were larger and more numerous in the rectum. In redo resections, Glut1-positive submucosal innervation in post-pullthrough specimens did not differ significantly from age-appropriate non-HSCR rectal controls and pelvic Glut1-positive nerves were never observed to penetrate the pulled-through colon. However, the density and caliber of Glut1-positive nerves in the neorectums were significantly greater than expected based on the prerectal location from which the pulled-through bowel originated.

CONCLUSIONS

Submucosal innervation in post-pullthrough specimens does not support the hypothesis that native pelvic nerves innervate the neorectum, but suggests remodeling occurs to establish the age-appropriate density and caliber of rectal Glut1-positive innervation. The latter should not be interpreted as transition zone pullthrough in a rectal biopsy from a previously done pullthrough.

Extragenital Mycoplasma genitalium infections among men who have sex with men

OBJECTIVES

There are limited data on the prevalence of Mycoplasma genitalium (Mgen) coinfection with rectal chlamydia (Chlamydia trachomatis (CT)) and rectal gonorrhoea (Neisseria gonorrhoeae (NG)) infections and few studies examining the prevalence of pharyngeal Mgen in men who have sex with men (MSM). Using transcription-mediated amplification assay, this study aimed to determine the proportion of rectal CT and rectal NG infections in MSM who are coinfected with rectal Mgen, and the proportion of MSM with Mgen detected in the pharynx in order to inform clinical practice.

METHODS

This was a cross-sectional study conducted at Melbourne Sexual Health Centre in Australia. Consecutively collected rectal swabs from MSM that tested positive for CT (n=212) or NG (n=212), and consecutively collected pharyngeal samples (n=480) from MSM were tested for Mgen using the Aptima Mycoplasma genitalium Assay (Hologic, San Diego). Samples were linked to demographic data and symptom status.

RESULTS

Rectal Mgen was codetected in 27 of 212 rectal CT (13%, 95% CI 9 to 18) and in 29 of 212 rectal NG (14%, 95% CI 9 to 19) samples, with no difference in the proportion positive for Mgen. MSM with rectal CT/Mgen coinfection had more sexual partners than those with rectal CT monoinfection (mean 6 vs 11, p=0.06). MSM with rectal NG/Mgen coinfection were more likely to be HIV-positive than those with rectal NG monoinfection (OR=2.96, 95% CI 1.21 to 7.26, p=0.023). MSM with rectal CT/Mgen coinfection were more likely to be using pre-exposure prophylaxis than MSM with rectal NG/Mgen coinfection (OR 0.25, 95% CI 0.10 to 0.65, p=0.002). Pharyngeal Mgen was uncommon and detected in 8 of 464 samples (2%, 95% CI 1% to 3%). Pharyngeal Mgen was associated with having a rectal STI (OR=10.61, 95% CI 2.30 to 48.87, p=0.002), and there was a borderline association with being HIV-positive (p=0.079).

CONCLUSION

These data indicate one in seven MSM treated for rectal CT or rectal NG will have undiagnosed Mgen that is potentially exposed to azithromycin during treatment of these STIs. Rectal Mgen coinfection was associated with specific risk factors which may inform testing practices. Pharyngeal Mgen was uncommon.

Dynamics of Vaginal and Rectal Microbiota Over Several Menstrual Cycles in Female Cynomolgus Macaques

The composition of the microbiota in cynomolgus macaques is only partially characterized, although this animal model is often used to study pathogenesis and preventive strategies against infections. We thus performed, for the first time, a longitudinal characterization of the vaginal and rectal microbiota of five cycling female cynomolgus macaques. Samples were collected weekly for 15 weeks and the V3/V4 regions of the16S rRNA gene sequenced. Sequences were analyzed with QIIME for OTU detection and taxonomic assignment. Progesterone levels were also determined to evaluate hormonal influence on bacteria relative abundance. The rectal and vaginal bacterial composition in cynomolgus macaques is polymicrobial and clearly distinct, with larger individual variability in the vagina. Rectal microbiota profiles were consistent between animals, whereas they were highly variable and animal-specific in the vagina. In the rectum, the most abundant taxa were Ruminococcaceae, Prevotella, and Clostridiales. In the vagina, the most abundant genera were Sneathia, Porphyromonas, Prevotella, and Fusobacterium. Lactobacillus were found at relative abundances higher than 1% in only one animal and were not predominant. Comparison of the vaginal cynomolgus macaque microbiota with that of humans showed similarity to community state type IV-A usually associated with dysbiosis. In the vagina, the relative abundance of 12 bacterial genera was found to be associated with progesterone levels. Our study provides a detailed characterization of the rectal and vaginal microbiota in female cynomolgus macaques and opens new perspectives of this animal model.

Expression of immune-related genes in rectum and colon descendens of Irritable Bowel Syndrome patients is unrelated to clinical symptoms

BACKGROUND

Mucosal immune activation has been postulated to play an important role in the pathogenesis of irritable bowel syndrome (IBS). However, data are conflicting and often based on small patient cohorts. Here, we aimed to evaluate the gene expression of a large set of immune-related genes in mucosal biopsies from IBS patients and healthy volunteers (HV).

METHODS

A total of 171 IBS patients and 127 HV were included in the study. Rectum biopsies were collected from a cohort of 70 HV and 77 IBS patients (Rome III) and colon descendens biopsies from another cohort of 57 HV and 94 IBS patients (Rome II). Gene expression was assessed using OpenArray technology, and validated questionnaires were used to evaluate clinical characteristics (GI symptoms, somatization, anxiety, and depression).

KEY RESULTS

A subset of IBS patients (33%) with increased immune activation in the colon descendens was identified using multivariate analysis and displayed increased gene expression of IL1B (3-fold change), prostaglandin synthase PTGS2 (2.1-fold change), and the G-protein-coupled receptor MRGPRX2 (10.7-fold change). Clinical characteristics in this subgroup were however similar to the rest of the patient cohort. Analysis of rectal biopsies failed to identify such subgroup of "immuno-active" IBS patients in the other patient cohort.

CONCLUSION

A subset of IBS patients reveals evidence of immune activation in the colon descendens, but not in the rectum; however, gene expression is unrelated to clinical symptoms. To what extent this subgroup might however respond to anti-inflammatory therapy remains to be investigated.

Management and outcome of colorectal cancer during pregnancy: report of 41 cases

BACKGROUND

Colorectal cancer in pregnancy is rare, with an incidence of 0.8 per 100,000 pregnancies. Advanced disease (stage III or IV) is diagnosed more frequently in pregnant patients. We aimed to review all cases of colorectal cancer in pregnancy from the International Network on Cancer, Infertility and Pregnancy database in order to learn more about this rare disease and improve its management.

METHODS

Data on the demographic features, symptoms, histopathology, diagnostic and therapeutic interventions and outcomes (obstetric, neonatal and maternal) were analysed.

RESULTS

Twenty-seven colon and 14 rectal cancer cases were identified. Advanced disease was present in 30 patients (73.2%). During pregnancy, 21 patients (51.2%) received surgery and 12 patients (29.3%) received chemotherapy. Thirty-three patients (80.5%) delivered live babies: 21 by caesarean section and 12 vaginally. Prematurity rate was high (78.8%). Eight babies were small for gestational age (27.6%). Three patients (10.7%) developed recurrence of disease. Overall 2-year survival was 64.4%.

CONCLUSION

Despite a more frequent presentation with advanced disease, colorectal cancer has a similar prognosis in pregnancy when compared with the general population. Diagnostic interventions and treatment should not be delayed due to the pregnancy but a balance between maternal and foetal wellbeing must always be kept in mind.

Unusual mucosal lesion: A case of rectal pseudolipomatosis in a 60-year-old patient

Pseudolipomatosis is a very rare benign pathologic condition of colorectal mucosa. It is caused by the presence of gas bubbles in the intestinal mucosa. The endoscopic and histologic aspects are misleading as they suggest adipocytic or vascular lesions. We present herein a case of rectal pseudolipomatosis in a 60-year-old woman presenting with rectal bleeding. The endoscopic pattern was not suggestive of the lesion, and the histopathologic analysis of the patient’s rectal biopsies revealed characteristic features of pseudolipomatosis. Rectocolic pseudolipomatosis is a very rare benign condition with challenging clinicopathologic presentation. Clinicians and pathologists should be aware of this uncommon lesion for correct diagnosis and appropriate clinical management.

Intramucosal fat is uncommon in large bowel polyps but raises three differential diagnoses

AIMS

This case series intends to expand currently limited knowledge regarding the existence and diagnostic significance of intramucosal fat in colorectal polyps.

METHODS

Clinicopathological features of nine such polyps were reported following histopathological review, including S100 and EMA immunohistochemistry.

RESULTS AND CONCLUSIONS

Such review subdivided seven polyps into three groups: (1) mucosal perineurioma/serrated polyps with fat among the perineurial stroma (three cases); (2) submucosal lipomas with adipose tissue extending into the overlying mucosa (two cases) and (3) polyps with intramucosal adipose tissue only, that is, the newly described but less-recognised entity known as intramucosal lipoma (two cases). The two remaining polyps of this series did not include submucosa but, from assessing their muscularis mucosae, were favoured to represent intramucosal lipomas. The first two phenomena are formally described for the first time by this case series. The last of these three diagnoses should prompt investigations for Cowden syndrome, but intramucosal lipomas are more often sporadic/non-syndromic.

Long-term outcomes of surgical management of rectal prolapse

BACKGROUND

Various surgical options for rectal prolapse are available but none have been shown to be clearly superior. The aims of this study were to investigate the long-term recurrence rate of a variety of surgical approaches, their associated morbidities and the types of reoperation used to treat recurrence.

METHODS

A retrospective analysis was performed of all cases of rectal prolapse surgery within one colorectal surgical unit between January 2000 and June 2017. Abdominal approaches consisted of rectopexy (RP) and resection rectopexy (RRP); perineal approaches included perineal rectosigmoidectomy (PR) and Delorme's repair (DR). Complications were graded according to the Clavien-Dindo classification. The median follow-up was 4.5 years (interquartile range 1.5-10.1, maximum 16.5). Statistical analysis was performed using Kaplan-Meier to determine recurrence rates.

RESULTS

A total of 157 patients were included in the study. The numbers for each procedure were: DR (n = 55), RRP (n = 44), RP (n = 38) and PR (n = 20). The majority were females (94%). The perineal group were significantly older than the abdominal group (80 versus 67 years, P = 0.0001). At 5 years, the recurrence rates were 52%, 30%, 5% and 3% for DR, PR, RP and RRP, respectively. Morbidity was highest in PR (20%) followed by RRP (18%), RP (16%) and DR (7%) (n.s.). The overall morbidity rates for perineal group and abdominal group were 10.7% and 17.1%, respectively (n.s.).

CONCLUSION

Abdominal approaches have a significantly lower recurrence rate at 5 years but tend to be associated with higher morbidity.

Colorectal cribriform comedo-type adenocarcinoma: a distinct subtype with poor prognosis?

Colorectal cancer is one of the most commonly diagnosed cancers in the world. It is a heterogeneous disease with several histologic subtypes, and some of them are associated with adverse prognostic factors. Cribriform comedo-type adenocarcinoma (CCA) has been included as a colorectal adenocarcinoma subtype in the last World Health Organization (WHO) classification of gastrointestinal system tumors. Some authors have linked this subtype to an adverse prognosis, but to the best of our knowledge there is only one previous report assessing its histologic and prognostic features. We herein review a series of CCA of the colon, emphasizing its clinical and morphological features.

Laparoscopy-Assisted Natural Orifice Specimen Extraction to Treat Tumors of the Sigmoid Colon and Rectum: The Short- and Long-Term Outcomes of a Retrospective Study

Background: Few studies have assessed the short- and long-term outcomes of laparoscopically assisted natural orifice specimen extraction (NOSE) in patients with sigmoid colon and rectal tumors. We investigated the short- and long-term outcomes of patients undergoing laparoscopic-assisted NOSE for tumors of the sigmoid colon and rectum. Methods: Ninety-eight patients with sigmoid colon and rectal tumors undergoing laparoscopic-assisted NOSE were included. The tumor was classified according to its distance from the anal verge: Group 1 (15-30 cm), Group 2 (5-15 cm), and Group 3 (≤5 cm). In Group 1 patients, a laparoscopic surgical specimen collection bag was used as a special transrectal device. In Group 2 patients, transanal endoscopic microsurgery device and specimen collection bag were used. In Group 3 patients, a Lone-Star retractor was used. The demographic characteristics and intra- and postoperative outcomes were measured. Results: In Group 1, 1 patient had respiratory disease and 1 had enterocolitis as short-term postoperative complications. One patient showed intestinal obstruction as a long-term postoperative complication. In Group 2, 2 patients had an ileus, 1 had an anastomotic leak, 2 had urinary retention, and 1 had respiratory disease as short-term complications. Only one patient had a long-term complication: anastomotic stenosis. In Group 3, short-term complications were present in 3 patients: 1 had hemorrhage, 1 had urinary retention, and 1 had respiratory disease. Long-term complications included one case of anastomotic stenosis and one of intestinal obstruction. Conclusions: NOSE is safe and cosmetically and theoretically superior to conventional laparoscopy when different devices are used according to the tumor's location.

Benign Granular Cell Tumor of the Cecum

Granular cell tumors (GCT) are usually benign, soft tissue tumors that are mostly found in the oral cavity, skin, and subcutaneous tissue. GCTs in the gastrointestinal (GI) tract are mainly located in the esophagus.

A 63-year-old male was referred to the gastroenterology clinic for a major complaint of six months of painless rectal bleeding. Laboratory results showed mild macrocytic anemia. He denied any prior colonoscopies and hence, a lower endoscopic procedure was done. The colonoscopy showed multiple polyps, one of them located at the cecum. The cecal polyp showed polygonal cells with abundant eosinophilic infiltration and S100 stain positive. This confirmed a diagnosis of GCT.

GCTs are thought to be derived from the neural tissue (Schwann cells). This entity is usually asymptomatic; however, tumors located at the lower GI tract can present with hematochezia. Only 2% of GCTs follow a malignant course, with associated poor prognosis. 

This case is being presented because of its asymptomatic nature. It is important to monitor these lesions in order to recognize early signs/symptoms concerning for malignancy.

Ambulatory assessment of colonic motility using the electromagnetic capsule tracking system

BACKGROUND

The Motilis 3D-Transit system tracks electromagnetic capsules as they traverse the gastrointestinal tract. The method is minimally invasive and ambulatory. Analysis has previously been limited to regional gut transit times, but new methods may allow detailed analysis of colonic motility.

METHODS

Parameters of colonic motility were analyzed from 34 3D-Transit recordings performed in healthy volunteers (median age 28 years; 8 F). Characteristic propulsive velocities and lengths of movement were determined to quantify common movement patterns. Data from seven patients with severe chronic diarrhea were included for comparison.

KEY RESULTS

Lack of capsule motion accounted for 82% (75%-87%) of total colonic transit time. Propulsive velocities were distributed with peaks at 0.5 cm/min (antegrade or retrograde) and 50 cm/min (antegrade). Based on velocity and length of propagation, five motor patterns were identified; (a) long fast antegrade, (b) fast antegrade, (c) slow antegrade, (d) slow retrograde, and (e) fast retrograde movements. Long fast antegrade movements were median 21 cm (10-96 cm). Capsule progression was faster during daytime than at night (5.9 cm/h vs 0.8 cm/h; P < 0.01). Colonic transit was faster in patients with chronic diarrhea than in healthy volunteers (5.4 h vs 18.2 h; P = 0.04), with higher capsule velocity (20.4 cm/h vs 4.4 cm/h; P < 0.01).

CONCLUSIONS AND INFERENCES

The 3D-Transit system now allows detailed description of colonic motility and our results are supported by those previously suggested by manometry. It holds promise for future assessment of movement patterns to characterize different diseases and effects of treatment.

Elevation in Cell Cycle and Protein Metabolism Gene Transcription in Inactive Colonic Tissue From Icelandic Patients With Ulcerative Colitis

BACKGROUND

A combination of genetic and environmental factors is thought to be involved in the pathogenesis of ulcerative colitis (UC). In Iceland, the incidence of UC is one of the highest in the world. The aim of this study was to characterize patients with UC and identify potential germline mutations and pathways that could be associated with UC in this population.

METHODS

Exome sequencing and genome-wide microarray analysis on macroscopically noninflamed colonic mucosa from patients and controls were performed. Exome sequence data were examined for very rare or novel mutations that were over-represented in the UC cohort. Combined matching of variant analysis and downstream influence on transcriptomic expression in the rectum were analyzed.

RESULTS

One thousand eight hundred thirty-eight genes were differentially expressed in rectal tissue from UC patients and identified an upregulation in genes associated with cell cycle control and protein processing in the endoplasmic reticulum (ER). Two missense mutations in thiopurine S-methyltransferase (TPMT) with a minor allele frequency of 0.22 in the UC patients compared with a reported 0.062 in the Icelandic population were identified. A predicted damaging mutation in the gene SLC26A3 is potentially associated with increased expression of DUOX2 and DUOXA2 in rectal tissue.

CONCLUSIONS

Colonic mucosa of UC patients demonstrates evidence of an elevation in genes involving cell proliferation and processing of proteins within the ER. Exome sequencing identified a possible increased prevalence of 2 damaging TPMT variants within the UC population, suggesting screening the UC population before initiation of thiopurine analogue therapy to avoid toxicity associated with these mutations.

Expression of Circulating miR-155, miR-21, miR-221, miR-30a, miR-34a and miR-29a: Comparison of Colonic and Rectal Cancer

BACKGROUND

Colorectal cancer is an increasing cause of death. Circulating microRNAs (miRs) could be great diagnostic and prognostic biomarkers of colorectal cancer, but further continuation of their utility is needed for their comprehensive application.

MATERIALS AND METHODS

Twenty-seven patients with colonic cancer, 16 with rectal cancer and 12 healthy volunteers as controls, were involved in this study. Expression of miR-155, miR-21, miR-221, miR-30a, miR-34a and miR-29a were determined by reverse transcription polymerase chain reaction (RT-PCR) from sera of patients.

RESULTS

Expression of miR-155, miR-21 and miR-221 was significantly higher in rectal cancer than in colonic cancer. There was no difference found between those with TNM1 cancer and controls for both cancer types. miR-155, miR-34a and miR-29a were down-regulated in all patients with cancer compared to controls. We did not find any statistically significant up-regulation of miR-221 in patients with colonic cancer compared to controls. In contrast, in patients with rectal cancer, miR-221 expression was higher than in controls. Advanced stage was also linked to higher miR-221 expression compared to early stage. Slight, but statistically significant increase was observed in miR-30a expression in patients with colon cancer compared to control individuals.

CONCLUSION

Our results partly support previous findings. Here we report on differences in the expression of circulating microRNA between colonic and rectal tumours for the first time.

HIV and SIV in Body Fluids: From Breast Milk to the Genitourinary Tract

HIV-1 is present in many secretions including oral, intestinal, genital, and breast milk. However, most people exposed to HIV-1 within these mucosal compartments do not become infected despite often frequent and repetitive exposure over prolonged periods of time. In this review, we discuss what is known about the levels of cell-free HIV RNA, cell-associated HIV DNA and cell-associated HIV RNA in external secretions. Levels of virus are usually lower than contemporaneously obtained blood, increased in settings of inflammation and infection, and decreased in response to antiretroviral therapy. Additionally, each mucosal compartment has unique innate and adaptive immune responses that affect the composition and presence of HIV-1 within each external secretion. We discuss the current state of knowledge about the types and amounts of virus present in the various excretions, touch on innate and adaptive immune responses as they affect viral levels, and highlight important areas for further study.

Gastrointestinal Stromal Tumours of the Rectum - Evaluating the National Registry Data with Respect to its Use in Clinical Practice

BACKGROUND

Gastrointestinal stromal tumours (GIST) are rare malignant mesenchymal tumours with an incidence of 1 in 100,000. They represent only 5% of gastrointestinal tumours. The GISTs are mainly located in the stomach (60-70%) and in the rectum in &lt; 5% of cases. In the case of localized, resectable tumours, the treatment is surgical resection. Depending on the size and localization of the tumour in the rectum, either a local excision, rectal resection with anastomosis, or abdominoperitoneal amputation with permanent stoma can be performed. In contrast to carcinomas, the metastasis of GISTs into lymph nodes is rare; therefore, from an oncological point of view, lymphadenectomy in the form of mesorectal excision is not required. Neoadjuvant treatment using tyrosine-kinase inhibitors (TKI) is recommended for tumours larger than 5 cm and in case of tumours infiltrating surrounding organs or sphincters in order to achieve complete resectability, less mutilating and continent procedure. In GISTs with a positive resection line, re-resection can be attempted. Adjuvant TKI therapy can be considered in cases of CD117 positivity and after resections of GISTs with medium and high-risk malignant behaviour. The TKI treatment is also indicated in cases of unresectable and metastatic GISTs.

METHODS

Data obtained from the GIST registry by the 1st January 2017, when 10 centres in the Czech Republic were contributing to the registry, were analysed.

RESULTS

We analysed 1,095 patients out of which 45 (4.1%) had GIST localized in the rectum. The average age of the patients was 60 years. There were significantly more males (68.9%; p = 0.0007) and symptomatic patients (62.2%; p = 0.034). In total, 82% of the patients underwent surgery. Local excision was performed in 37.8%, resection of the rectum with anastomosis in 29.7%, and Miles operation in 29.7%. In the cohort, most tumours were 2-5 cm in size and almost half of the tumours presented a high risk of malignant behaviour. Systemic treatment was reported in 73% of patients. A complete remission was achieved in 80% of patients with GIST of the rectum. The median survival rate was 11.3 years and the 5-year survival rate is 90.6%.

CONCLUSION

Despite the success of TKI treatment, the only potentially curative method of rectal GISTs is a surgical R0 resection. Given the relatively rare frequency of these tumours, proper diagnosis and treatment is demanding. Therefore, these patients should be preferably treated in specialised centres. This work was supported by grant MH CZ - RVO (FNBr, 65269705).  The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 19. 12. 2018 Accepted: 2. 2. 2019.

Radial-scanning flexible EUS of the anorectum and pelvis

Standard upper gastrointestinal flexible radial EUS probes are well suited for imaging of anorectum and pelvic pathologies. They offer multiple advantages over conventional rigid rectal probes. The current transducers allow imaging at variable frequencies and are Doppler capable. The flexible shaft of the endoscope and optics allow easy probe insertion to upper sigmoid. Flexible radial EUS probes allow evaluation of anal sphincter complex, rectosigmoid mural pathologies, and paraluminal pelvic disorders. A thorough understanding of pelvic anatomy and image orientation is the key to appropriate image interpretation. In this review, we describe the principles and methodology for anorectal EUS imaging using a flexible radial EUS probe.

An Aubergine in My … Case of Rectal Foreign Body

A 24-year-old man presented to the casualty department with a history of left-sided, colicky abdominal pain for one day. It was associated with an inability to pass flatus or motion within the same duration. There was no history of vomiting. On examination, the vital signs were within normal limits, and he was afebrile. His abdomen was soft, but a hard mass was palpable on the left side of his abdomen. There was no peritonitis. The bowel sounds were sluggish.