Average Daily Gain in Lambs Weaned at 60 Days of Age Is Correlated with Rumen and Rectum Microbiota

Colonization of gastrointestinal microbiota in mammals during early life is vital to host health. The objective of this study was to investigate whether lambs with high and low ADG have a different rumen and rectum microbial community. Thus, we investigated potential relationships between rumen and rectum microbiota and average daily gain (ADG) in weaned lambs. Sixteen lambs with similar body weights (7.63 ± 1.18 kg) were selected at 30 days of age. At 60 days of age, lambs were weaned, and ADG was calculated from 60 to 90 days. Then, two groups were generated: higher ADG (HG, 134.17 ± 13.48 g/day) and lower ADG (LG, 47.50 ± 19.51 g/day). Microbiota was evaluated at 30, 60, and 90 days of age. The final live weight and ADG at 90 days of age was higher (p < 0.05) in the HG group compared to the LG group. The maturity of bacterial and fungal communities was increased (p < 0.05) in the HG group for the 30 days vs. 90 days comparison and 60 days vs. 90 days comparison. Linear discriminant analysis effect size (LEfSe) analysis revealed a total of 18 bacterial biomarkers that are ADG-specific in the rumen and 35 bacterial biomarkers in the rectum. Meanwhile, 15 fungal biomarkers were found in the rumen and 8 biomarkers were found in the rectum. Our findings indicated that ADG is related to the rumen and rectum microbiota in lambs.

The role of rectal ultrasound in children with functional constipation

AIM

The study aimed primarily to compare the transverse rectal diameter in children with functional constipation (FC) and children without constipation in different age groups, and between cases of constipation at baseline and after treatment. Secondary aim was to determine factors that could affect the transverse rectal diameter.

METHODS

A controlled prospective study, including a total of 100 children between the ages of 2 and 11 years, who were divided into 50 patients suffering from constipation according to Rome IV criteria and 50 age- and sex-matched controls. Transverse rectal diameter was measured at presentation, and after 3 months of laxative therapy and behavioural modification.

RESULTS

Initial rectal diameter was significantly different between cases (3.55 cm (interquartile range, IQR), 3.2-4) and controls (2.3 cm (IQR, 1.8-2.5)), P value < 0.001, and it was also significantly different between those above and below 4 years, so a separate cut-off point for diagnosis of constipation was suggested being >3 cm for the former and >2.5 cm for the latter. After 3 months of follow-up, rectal diameter significantly reduced to become 2.6 (IQR, 2-2.8), P value < 0.001. Duration of symptoms positively correlated with rectal diameter.

CONCLUSIONS

Ultrasound measurement of rectal diameter is an important tool to diagnose and follow-up functional constipation in children. Different values of rectal diameter are found between those above and below 4 years of age.

Comparative genomics and phenotypic studies to determine site-specificity of Escherichia coli in the lower gastrointestinal tract of humans

Escherichia coli (E. coli) is an important commensal in the human gut; however, it is unknown whether strains show site-specificity in the lower gut. To investigate this, we assessed genotypic and phenotypic differences in 37 clone pairs (two strains with very similar multiple locus variable-number-tandem-repeat analysis [MLVA] profiles) of E. coli isolated from mucosal biopsies of two different gut locations (terminal ileum and rectum). The clone pairs varied at the genomic level; single nucleotide polymorphisms (SNPs) were common, multiple nucleotide polymorphisms (MNPs) were observed but less common, and few indels (insertions and deletions) were detected. The variation was higher in clone pairs that are associated with non-human-associated sequence types (ST) compared to human-associated STs, such as ST95, ST131, and ST73. No gene(s) with non-synonymous mutations were found to be commonly associated with either the terminal ileum or the rectal strains. At the phenotypic level, we identified the metabolic signatures for some STs. Rectum strains of some STs showed consistently higher metabolic activity with particular carbon sources. Clone pairs belonging to specific STs showed distinct growth patterns under different pH conditions. Overall, this study showed that E. coli may exhibit genomic and phenotypic variability at different locations in the gut. Although genomics did not reveal significant information suggesting the site-specificity of strains, some phenotypic studies have suggested that strains may display site-specificity in the lower gut. These results provide insights into the nature and adaptation of E. coli in the lower gut of humans. To the best of our knowledge, no study has investigated or demonstrated the site-specificity of commensal E. coli in the human gut.

A rectal gastrointestinal stromal tumor case accompanied by elevated CEA mimicking rectal carcinoma on 18F-FDG PET/CT

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasm arising from gastrointestinal tract and can be benign or malignant. Rectal GISTs are rare and have poor prognosis. We here reported an older male who presented with features of distending discomfort in the rectum and pain in the anus due to a large rectal tumor. Physical examinations detected a mass in the rectum without blood staining on the gloved finger. Carcinoembryonic antigen (CEA) was found to be slightly elevated and the prostate-specific antigen level was normal. ¹⁸F-FDG PET/CT showed a soft tissue density mass at the bottom of the pelvic, with an unclear boundary to the surroundings with the significantly increased FDG uptake (SUVmax 17.5). Although a rectal carcinoma was suspected based on the finding of PET/CT and CEA, the histopathological examination confirmed the diagnosis of the malignant GIST of the rectum. The patient was then treated with imatinib and on follow-up regularly. In this case, ¹⁸F-FDG PET/CT shows the advantage of visualizing both primary and metastatic lesions and provides valuable information for the diagnosis, staging, evaluation, and prognosis of GIST.

Sessile serrated lesion presenting as large pedunculated polyp in the rectum: A case report

RATIONALE

Sessile serrated lesions (SSLs) are serrated polyps (SP) with the typical serrated architecture of the crypt lining epithelium. SSL has an important clinical implication because they are recognized as precursor lesion of sporadic colorectal cancer (CRC) through "serrated pathway." SSLs usually appear flat to sessile, and are located in the right colon.

PATIENT CONCERNS

A 69-year-old man was referred to a tertiary medical center because of intermittent hematochezia for 2 years.

DIAGNOSIS

Colonoscopy revealed a large, pedunculated polyp in the rectum. The polyp surface was slightly reddish in color and the elongated stalk was covered with almost normal mucosa. Histopathological examination of the resected specimens revealed the typical features of SSL with low-grade dysplasia.

INTERVENTION

Endoscopic mucosal resection using a detachable snare was performed on the tumor for definite diagnosis and treatment.

OUTCOMES

There was no evidence of immediate or delayed bleeding after endoscopic mucosal resection, and the hemoglobin level normalized after a 1-year follow-up.

LESSONS

We report a rare case of a large pedunculated polyp with typical histological features of SSLs in the rectum. Endoscopists should always consider SSLs at any location even with unusual morphological findings.

A Race-Specific, DNA Methylation Analysis of Aging in Normal Rectum: Implications for the Biology of Aging and Its Relationship to Rectal Cancer

Approximately 90% of colorectal cancer (CRC) develop over the age of 50, highlighting the important role of aging in CRC risk. African Americans (AAs) shoulder a greater CRC burden than European Americans (EA) and are more likely to develop CRC at a younger age. The effects of aging in AA and EA normal rectal tissue have yet to be defined. Here, we performed epigenome-wide DNA methylation analysis in the first, large-scale biracial cohort of normal rectum (n = 140 samples). We identified increased epigenetic age acceleration in EA than AA rectum (p = 3.91 × 10^-4) using linear regression. We also identified differentially methylated regions (DMRs) associated with chronological aging in AA and EA, separately using DMRcate. Next, a consensus set of regions associated with cancer was identified through DMR analysis of two rectal cancer cohorts. The vast majority of AA DMRs were present in our analysis of aging in rectum of EA subjects, though rates of epigenetic drift were significantly greater in AA (p = 1.94 × 10^-45). However, 3.66-fold more DMRs were associated with aging in rectum of EA subjects, many of which were also associated with rectal cancer. Our findings reveal a novel relationship between race, age, DNA methylation and rectal cancer risk that warrants further investigation.

18F-FDG PET/CT imaging of primary malignant melanoma of rectum with liver metastases mimicking rectum cancer: case report and literature review

Malignant melanoma (MM) is an aggressive malignant tumor, which mostly occurs on the skin, uvea, etc. The mucosal MM accounts for a small proportion of all MM and can occur in the digestive tract. Primary MM of the digestive tract is rare and can be found in the middle and lower third of the esophagus and the rectum containing melanocytes. Primary rectal MM often occurs in middle-aged and elderly women, with rapid progress and strong invasion. We report a case of a 61-year-old man diagnosed with primary malignant melanoma of the rectum with liver metastases mimicking rectum cancer. ¹⁸F-FDG PET/CT showed the rectal wall was markedly thickened with a high metabolic level (SUVmax 10.6) and the boundary between the lesions and the prostate was unclear. In addition, increased FDG uptake were found in multiple lymph nodes, lung, liver, and bones, suggesting metastasis. In this case, ¹⁸F-FDG PET/CT shows the advantage of evaluating the whole-body situation and provides valuable information for the diagnosis, tumor stage, evaluation of treatment efficacy, and prognosis of MM.

Severe lower gastrointestinal bleeding caused by rectal Dieulafoy's lesion: Case reports and literature review

RATIONALE

Dieulafoy's lesion are relatively rare and can cause severe gastrointestinal bleeding. A Dieulafoy's lesion is defined as an artery that erodes the overlying epithelium without the presence of an ulcer. Bleeding in Dieulafoy's lesion predominantly involves the proximal stomach and upper gastrointestinal tract and is rarely observed in the lower gastrointestinal tract.

PATIENT CONCERNS

Case 1 was a 58-year-old woman complaining of sudden headache and vomiting who was diagnosed with subarachnoid hemorrhage. She underwent transcatheter embolization for intracranial aneurysm treatment but had an acute profuse hematochezia on the 11th day of admission. Case 2 was a 63-year-old man admitted to the respiratory intensive care unit because of fever with altered consciousness level for a week. He was diagnosed with advanced lung cancer that had metastasized to multiple organs one month prior. On the third day of admission, he had an attack of profuse hematochezia, and quickly developed shock and apathy.

DIAGNOSIS

Both patients were diagnosed with actively bleeding rectal Dieulafoy's lesion by bedside emergency colonoscopy.

INTERVENTIONS

Endoscopic hemostatic clipping was performed in 2 patients.

OUTCOMES

Hemostasis was successfully achieved in these 2 patients, and there was no recurrence of symptoms during follow-up.

CONCLUSIONS

We propose that hemostatic clipping is one of the options in the treatment of rectal Dieulafoy's lesions.

Interobserver reliability of the Nancy index for ulcerative colitis: An assessment of the practicability and ease of use in a single-centre real-world setting

BACKGROUND

Histological disease severity assessment in ulcerative colitis (UC) has become a mainstay in clinical endpoints definition ("histologic remission") in clinical trials of UC. Several scores are established in the microscopical assessment of disease activity, but the Nancy index (NI) stands out being a histological index with the least amount of scoring items among these scores. To which extent histologic assessment using NI is affected by interobserver reliability in a real word setting, is poorly understood. We therefore performed a single-center retrospective analysis of NI assessment in patients with UC.

METHODS

We retrospectively evaluated the NI in two independent cohorts (total: 1085 biopsies, 547 UC patients) of clinically diagnosed UC patients, who underwent colonoscopy between 2007 and 2020. Cohort #1 consisted of 637 biopsies from 312 patients, Cohort #2 consisted of 448 biopsies from 235 patients. Two blinded pathologists with different levels of expertise scored all biopsies of each cohort. A consensus conference was held for cases with discrepant scoring results. Finally, an overall consensus scoring was obtained from both cohorts.

RESULTS

The interobserver-agreement of the NI was substantial after the assessment of 1085 biopsy samples (κ = 0.796 [95%-CI: 0.771-0.820]). An improvement of the interobserver-agreement was found with growing numbers of samples evaluated by both observers (Cohort #1: κ = 0.772 [95%-CI: 0.739-0.805]; Cohort #2: κ = 0.829 [95%-CI: 0.793-0.864]). The interobserver discordance was the highest in NI grade 1 (observer 1: n=128; observer 2: n=236). Interobserver discordance was the lowest in NI grades 0 (observer 1: n=504; observer 2: n=479) and 3 (observer 1: n=71; observer 2: n=66).

CONCLUSION

The NI is an easy-to-use index with high interobserver reliability to assess the histological disease activity of UC patients in a real-world setting. While NI grades 0 and 3 had a high level of agreement between the observers, NI grade 1 had a poorer agreement-level. This highlights the clinical need to specify histological characteristics leading to NI grade 1.

Nanoparticles Loaded with Platinum Drugs for Colorectal Cancer Therapy

Colorectal cancer is a common cancer in both men and women. Numerous studies on the therapeutic effectiveness of nanoparticles against colorectal cancer have been reported. Platinum treatments as well as other medications comprising of nanoparticles have been utilized. Drug resistance restricts the use of platinum medicines, despite their considerable efficacy against a variety of cancers. This review reports clinically licensed platinum medicines (cisplatin, carboplatin, and oxaliplatin) combined with various nanoparticles that have been evaluated for their therapeutic efficacy in the treatment of colorectal cancer, including their mechanism of action, resistance, and limitations.

The anorectal defaecation reflex: a prospective intervention study

AIM

Our hypothesis is that there may be a neural pathway with sensory afferent neurons in the anal canal that leads to rectal contraction to assist defaecation. We aimed to compare rectal motility between healthy participants with or without anal anaesthesia.

METHOD

This prospective intervention study consisted of two test sessions: a baseline session followed by an identical second session. During each session we performed the anal electrosensitivity test, the rectoanal inhibitory reflex test and rapid phasic barostat distensions. Prior to the second session, participants were randomly assigned to receive either a local anal anaesthetic or a placebo.

RESULTS

We included 23 healthy participants aged 21.1 ± 0.5 years, 13 of whom received an anal anaesthetic and 10 a placebo. All participants showed a transient rectal contraction during the first test session, which decreased significantly after anal anaesthesia (18.6 ml vs. 4.9 ml, p = 0.019). The maximum rectal contraction was comparable to the baseline results in the placebo group. Furthermore, the electrosensitivity at the highest centimetre of the anal canal correlated with the maximum rectal contraction (r = -0.452, p = 0.045).

CONCLUSION

All healthy study participants display an involuntary, reproducible rectal reflex contraction that appears to be innervated by afferent nerves in the proximal anal canal. The rectal reflex contraction appears to play a role in defaecation and we therefore refer to this phenomenon as the anorectal defaecation reflex. Knowledge of the anorectal defaecation reflex may have consequences for the diagnostics and treatment of constipation.

Dedifferentiated liposarcoma (DDLPS) in the rectum: A case report

Dedifferentiated liposarcoma (DDLPS) is a rare subtype of liposarcoma with a poor prognosis. This current case report describes a rectal DDLPS in a 68-year-old Chinese male that presented with lower abdominal pain and weight loss. Computed tomography and magnetic resonance imaging were undertaken to evaluate the tumour. The patient underwent radical resection of the rectal tumour, sigmoid colostomy and partial ureterectomy. The tumour was positive for mouse double minute 2 by immunohistochemistry. The patient healed well but refused chemotherapy postoperatively for economic reasons. The tumour recurred and metastasized 4 weeks after the operation. After relevant treatment, the patient's condition deteriorated and he died of shock, metabolic acidosis, hyperlactataemia and acute renal failure. The case report also reviews the literature in terms of the clinical diagnosis, treatment and pathological characteristics of rectal DDLPS with the aim of improving the level of diagnosis and treatment.

Pictorial essay on MRI local staging of rectal carcinoma: An easy approach

Rectal cancer is common and accounts for more than one-third of colorectal tumors. It is associated with significant morbidity and mortality. Previously computed tomography scan is the key imaging modality in preoperative assessment to detect local invasion and distant metastasis. However, the advent of magnetic resonance imaging (MRI) has aided in local staging and prognosticates the outcome of rectal tumor. Here, the author briefly explains why rectal MRI has a comprehensive role and provides a simple and easy way in reporting an MRI rectal carcinoma, even for a non-radiologist.

Impacts of the SARS-CoV-2 Pandemic on Young Adult Colorectal Cancer Survivors

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has disrupted health care globally with dramatic impacts on cancer care delivery in addition to adverse economic and psychological effects. This study examined impacts of the SARS-CoV-2 pandemic on young adult colorectal cancer (CRC) survivors diagnosed age 18-39 years. Nearly 40% reported delays in cancer-related care, loss of income, and poorer mental health during the pandemic. Impacts were greater for survivors aged 20-29 years, with nearly 60% reporting cancer care delays and 53% experiencing income loss. Such impacts may result in detrimental downstream outcomes for young CRC survivors, requiring specific support, resources, and continued monitoring.

Spontaneous regression of a rectal tonsil presenting as a large submucosal tumor

Rectal tonsils are localized hyperplastic lymphoid tissues in the rectum, and the initial endoscopic findings are consistent with those for neoplastic lesions. However, rectal tonsils are benign entities, and the diagnosis should be made cautiously. A 70‐year‐old man presented with pain on defecation with rectal bleeding. Colonoscopy revealed a 3‐cm protruding mass in the rectum with mucosal erosion, but no malignant features were observed on forceps biopsy. Endoscopic ultrasonography (EUS) showed that the lesion was a hypoechoic mass without blood flow. Fine needle aspiration under EUS revealed no malignant components, although the size of the lesion had shrunk, and symptoms, such as blood‐stained stool, tenesmus, and discomfort during defecation, had resolved. A second forceps biopsy showed intermediate‐sized lymphocytes without lymphoepithelial lesions. Based on immunostaining, the lesion was diagnosed as a rectal tonsil.

Rectal tonsils occur due to localized proliferation of reactive lymphoid follicles in the submucosa or muscularis mucosa. However, endoscopic diagnosis is difficult since less invasive treatment is performed for neoplastic lesions of the rectum to preserve the function of the anal sphincter. Diagnosis and treatment of small lesions might be possible by endoscopic resection; however, for relatively large lesions, formulating a diagnosis based only on biopsy specimens becomes even more difficult. Therefore, repeated biopsies might be helpful for the diagnosis of rectal tonsils and for excluding other neoplasms.

Randomised controlled trial on the effect of simethicone bowel preparation on rectal variability during image-guided radiation therapy for prostate cancer (SPoRT study)

INTRODUCTION

The purpose of this study was to assess whether simethicone reduces the rectal volume (RV) and gas volume (GV), to increase treatment accuracy and to decrease toxicity of prostate radiation therapy.

METHODS

30 patients were randomised to simethicone or no intervention. Cone-beam computed tomography (CBCT) scans were performed on Days 1-3 and weekly until completion of radiation. RV and GV were measured using volume delineation. Toxicity data were collected.

RESULTS

264 CBCTs were analysed. RV and GV were not significantly different in the simethicone group compared with the control group at each time point (P >0.05) after adjusting for Week 0 values as a covariate. The simethicone group showed an average reduction in RV and GV of 10% and 21%, respectively, compared with the control group (P >0.05). Standard deviations were calculated over 10 time points, which were grouped to represent the first 2-3 weeks of radiation therapy versus subsequent weeks. These were not significantly different between the simethicone and control group. However, there was a statistically significant decrease in the variability of RV at time points 6-10 compared with time points 1-5 within the simethicone group (P = 0.012), but no significant difference was found between these grouped time points in the control group (P = 0.581). The toxicity questionnaires showed no significant difference between the groups.

CONCLUSIONS

Simethicone did not decrease the RV or GV overall. However, simethicone appeared to significantly decrease the RV variability from Week three onwards. This suggests that taking simethicone two to three weeks before starting radiation therapy may reduce RV variability, although a larger study is needed to confirm this.

The Variation of Duck RIG-I-Mediated Innate Immune Response Induced by Different Virulence Avian Influenza Viruses

In recent years, the emerging highly pathogenic avian influenza (HPAI) A(H5N8) virus has been reported with features of widely spread, an expanding host range, and cross-species transmission, attracting wide attention. The domestic duck plays a major role in the epidemiological cycle of the HPAI H5N8 virus, but little is known concerning innate immune responses during influenza infection in duck species. In this study, we used two wild-bird-origin viruses, H5N8 and H4N6, to conduct duck infection experiments, and detect the load of the two viruses, and retinoic acid-inducible gene I (RIG-I) and interferon β (IFN-β) in the host's natural immune response. Through comparison, it is found that the expression levels of RIG-I and IFN-β are both fluctuating. The innate immunity starts rapidly within 6 h after infection and is inhibited by the virus to varying degrees. The expression of RIG-I and IFN-β decreased on 1-2 days post-infection (dpi). The HPAI H5N8 virus has a stronger inhibitory effect on RIG-I than the low pathogenic avian influenza (LPAI) H4N6 virus and is the strongest in the lungs. After infection with HPAI H5N8 virus, 2 dpi, viral RNA replicates in large amounts in the lungs. It has been proven that RIG-I and IFN-β play an important role in the innate immune response of ducks to HPAI H5N8 virus infection, especially in the lungs. The main battlefield of RIG-I and IFN-β after infection with the LPAI H4N6 virus is in the rectum. Both viruses have been effectively controlled after 7 dpi. These results will help to understand the transmission mechanisms of avian influenza virus in wild ducks and help effectively prevent and control avian influenza.

A Novel Murine Model of a High Dose Brachytherapy-Induced Actinic Proctitis

Background

Radiation proctitis affects 1-20% of cancer patients undergoing radiation exposure due to pelvic malignancies, including prostate, gynecological and rectum cancers. The patients manifest rectal discomfort, pain, discharge, and bleeding. Notably, the efficacy of prophylactic measures remains controversial due to the lack of adequate animal models that mimic this condition.

Objective

The present study then aimed to develop a murine model of high-dose-rate (HDR) brachytherapy-induced proctitis.

Material/Methods

C57BL/6 male mice were subjected to HDR (radiation source: iridium-192 [Ir-192]) through a cylindrical propylene tube inserted 2 cm far from the anal verge into the rectum. The animals received radiation doses once a day for three consecutive days (fractions of 9.5 Grays [Gy]), 3.0 mm far from the applicator surface. The sham group received only the applicator with no radiation source. The survival rate was recorded, and a colonoscopy was performed to confirm the tissue lesion development. Following euthanasia, samples of the rectum were collected for histopathology, cytokines dosage (IL-6 and KC), and immunohistochemical analysis (TNF-α and COX-2).

Results

HDR significantly reduced animals’ survival ten days post first radiation exposure (14% survival vs. 100% in the non-irradiated group). Day seven was then used for further investigation. Mice exposed to radiation presented with rectum injury confirmed by colonoscopy and histopathology (P < 0.05 vs. the control group). The tissue damage was accompanied by an inflammatory response, marked by increased KC and IL-6 tissue levels, and immunostaining for TNF-α and COX-2 (P < 0.05 vs. control group).

Conclusions

We established a novel animal model of actinic proctitis induced by HDR brachytherapy, marked by inflammatory damage and low animal mortality.

Investigation of vaginal and rectal swabs of women infected with COVID-19 in two hospitals covered by Mazandaran University of Medical Sciences, 2020

Due to the emergence of COVID-19 virus worldwide and need to identify ways of transmitting the virus, we conducted a cross-sectional study from July to November 2020 on 80 women with COVID-19 infection was confirmed by nasopharyngeal proper time polymerase chain reaction (RT-PCR). We investigated SARS-CoV-2 in their vaginal and rectal swabs. The results showed that (n = 6, 7.5%) patients had positive rectal PCR and (n = 10, 12.5%) had positive vaginal PCR. There was a statistically significant relationship between positive rectal test and positive vaginal test (p=.001). Positive rectal PCR was significantly higher in women over 60 years old than in other age groups (p=.004).Impact StatementWhat is already known on this subject? In the past studies, the presence of the virus in the vagina and rectum was less or not confirmed.What do the results of this study add? The results of our study showed that the COVID-19 virus can infect the vagina and rectum of women.What are the implications of these findings for clinical practice and/or further research? This finding should be considered in sexual transmission and mother to child transmission and also vaginal colonisation, especially at the time of delivery.

Differential correlation network analysis of rectal transcriptomes reveals cystic fibrosis-related disturbance

Background: Intestinal pathology in cystic fibrosis (CF) remains mechanistically underexplored. Aim: We hypothesized that differential correlation network analysis of expression data would reveal hub genes of CF-related disturbance in the large bowel. Materials & methods: Transcriptomes of 29 rectal tissue samples were accessed at ArrayExpress (E-GEOD-15568 by Stanke et al.). Results: We identified 279 transcript pairs differentially correlating in CF and controls, including: ESRRA and RPL18 (r_CF = 0.55; r_controls = -0.68; p_adj = 1.60 × 10^-100), SRP14 and FAU (r_CF = -0.69; r_controls = 0.48; p_adj = 2.99 × 10^-90), SRP14 and GDI2 (r_CF = -0.34; r_controls = 0.60; p_adj = 1.05 × 10^-78). The genes related to membrane protein targeting (q = 8.34 × 10^-14) and one cluster was clearly linked to male infertility. Conclusion: FAU, SRP14 and GDI2 may be involved in a compensatory protein trafficking mechanism in CF rectum, highlighting their potential therapeutic value.

Malignant Gastrointestinal Stromal Tumor of Rectum: A Case Report and Review of Literature

Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal tract accounting for less than 1% of all gut tumors. GISTs occurring in the rectum are extremely rare and these usually present at an advanced stage compared with other sites.

We report a case of a middle-aged female who presented with features of anemia and subacute obstruction due to a large rectal tumor and underwent abdominoperineal resection. The histopathological examination confirmed the diagnosis of high-grade malignant GIST with multiple lymph nodal metastasis. She was started on adjuvant imatinib therapy and is on follow-up without any evidence of recurrence.

The authors conclude that GIST must be included in the differential diagnosis of a rectal tumor. Diagnosis is established by biopsy and immunohistochemistry studies. Surgical resection with histological negative margins is the standard curative treatment. Adjuvant targeted therapy can reduce long-term recurrence in high-risk cases.

Minimally Invasive Endoscopic and Surgical Management of Rectal Neoplasia

Rectal cancer demonstrates a characteristic natural history in which benign rectal neoplasia precedes malignancy. The worldwide burden of rectal cancer is significant, with rectal cancer accounting for one-third of colorectal cancer cases annually. The importance of early detection and successful management is essential in decreasing its clinical burden. Minimally invasive treatment of rectal neoplasia has evolved over the past several decades, which has led to reduced local recurrence rates and improved survival outcomes. The approach to diagnosis, staging, and selection of appropriate treatment modalities is a multidisciplinary effort combining interventional endoscopy, surgery, and radiology tools. This review examines the currently available minimally invasive endoscopic and surgical management options of rectal neoplasia.

Clinical and Molecular Characteristics of Rare Malignant Tumors of Colon and Rectum

Simple Summary

Tumors of colon and rectum other than adenocarcinomas represent a neglected issue from clinical and laboratory points of view because of their rarity. In this review, we summarize and describe the rare histologic entities occurring in colon and rectum. Clinical and pathologic characteristics, prognostic behavior, treatments, and altered genes are reported to provide readers with a paramount and comparative perspective. In relation to this, we propose that improvements in registries and multidisciplinary research are warranted to ameliorate their management.

Abstract

The most frequent form of colorectal cancer is represented by adenocarcinoma being about 98% of tumor histological types. However, other rare histotypes can be found in colon and rectum (adenosquamous, goblet cell adenocarcinoma, lymphoma, medullary carcinoma, melanoma, mesenchymal, neuroendocrine, plasmacytoma, signet ring, squamous tumors). Altogether, these forms account for less than 2% of colorectal tumors. There are no specific diagnostic or therapeutic recommended approaches and most of the information available from literature derives from small and retrospective clinical series. In the present study, we provide a paramount and updated view on clinical and biologic characteristics of rare colorectal tumors.

Schwannoma of the Rectosigmoid Colon

Schwannoma is a rare tumor in the colon which originates from the peripheral nerve plexus. Most of the cases have been asymptomatic but occasionally present as an obstructive mass. Abdominal investigations are effective in some cases, but usually, they are not informative. A significant number of cases have been detected after their operation by histopathology examination. Immune and histochemical staining shows the spindle cells that have been positive for S-100 and vimentin, but negative for CD34 and smooth muscle actin. If the diagnosis of Schowannoma is confirmed preoperatively, segmental resection is recommended. In this case report, we presented a 58-year-old woman with pelvic mass and normal colonoscopy that mimic extramural large uterine myoma with extraluminal pressure effect on the rectosigmoid.

Rectovaginal Fistula in Crohn's Disease: When and How to Operate?

Rectovaginal fistula (RVF) occurring during the course of Crohn's disease (CD) constitutes a therapeutic challenge and is characterized by a high rate of recurrence. To optimize the outcome of CD-related RVF repair, the best conditions for correct healing should be obtained. Remission of CD should be achieved with no active proctitis, the perianal CD activity should be minimized, and local septic complications should be controlled. The objective of surgical repair is to close the fistula tract with minimal recurrence and functional disturbance. Several therapeutic strategies exist and the approach should be tailored to the anatomy of the RVF and the quality of the local supporting tissues. Herein, we review the medical and surgical management of CD-related RVF.