Rectal malakoplakia mimicking advanced rectal cancer: A case report

Background

Malakoplakia is a rare acquired chronic infectious granulomatous condition, that is characterized by the accumulation of large granular macrophages containing basophilic inclusion bodies in the cytoplasm termed Michaelis-Gutmann (MG) bodies. Malakoplakia most commonly involves the genitourinary system, and the second most commonly affected site is the gastrointestinal tract. Rectal malakoplakia is an unusual entity that is difficult to diagnose due to its diverse clinical manifestations and radiological findings that are similar to different diseases and advanced cancers.

Case description

A 61-year-old male patient presented with difficulty in urination and defecation that started 4 months prior, along with a weight loss of 10 kg. Abdominal computerized tomography (CT) scanning revealed diffuse lesions of the perirectal region with multiple lymphadenopathies and involvement of the bladder, prostate, bilateral seminal vesicles, and left ureter. 18F-FDG PET/CT MIP showed intense FDG uptake in the rectal region, and a diagnosis of an occupying lesion was proposed. Colonoscopy and histological examination of rectal lesion biopsies showed the characteristic features of malakoplakia.

Conclusion

Malakoplakia of the rectum with lymph node involvement and adjacent organ extension has been extensively misdiagnosed in clinical practice, and mimics malignancy radiologically. It is of great importance for radiologists to be aware of malakoplakia when making the differential diagnosis of benign and malignant mass lesions of the rectum, although the radiologic findings are nonspecific. Endoscopic evaluation and pathologic examination of a biopsy should be recommended to make the correct diagnosis, which may prevent unnecessary surgical resection.

Stercoral colitis: CT imaging findings and clinical risk factors

PURPOSE

To describe and update stercoral colitis clinical risk factors, relative frequency, location, and CT imaging features correlated with surgical and pathological results.

METHODS

CT reports over a 5-year period (05/2017-05/2022) at a single medical center were searched. Main inclusion criteria were luminal distention with formed stool, wall thickening, and surrounding inflammation. Positive cases were graded as mild (early or developing stercoral colitis) versus moderate-to-severe based on CT findings. Medical records were reviewed for risk factors and outcome data in moderate-to-severe cases. P-values were tabulated for comparison.

RESULTS

545 total cases (71 (60, 82) years, 278 males) were identified on CT, including 452 mild (82.9%) and 93 moderate-to-severe cases (17%, 67 (55, 79) years, 48 females). Twenty cases showed evidence of perforation (3.7% total cohort, 22% moderate-to-severe cohort). Diagnosis as an incidental finding was frequent (46.0% of mild cases). Most cases involved the rectum (97.6% of mild cohort and 69% of moderate-to-severe cohort). The sigmoid was involved in 31% of moderate-to-severe cases, but 95% of the perforated subcohort (19/20, 13/20 without rectal involvement). Among the moderate-to-severe cohort, perforation was associated with slightly increased wall thickness (6.4 vs. 5.7 mm, p = 0.03), opioid use (50 vs. 23%, p = 0.04), and disease-specific mortality (11 vs. 0%, p =0.04). Perforation was less associated with major neurocognitive disorders (20 vs. 60%, p = 0.003), institutionalized status (5 vs. 38%, p = 0.005), and a prescribed bowel regimen (30 vs. 63%, p = 0.01).

CONCLUSION

Stercoral colitis may be under-reported. Perforation tends to favor sigmoid involvement and a less traditional patient cohort.

Endometriosis with colonic and rectal involvement: surgical approach and outcomes in 142 patients

PURPOSE

Endometriosis involving the colon and/or rectum (CRE) is operatively managed using various methods. We aimed to determine if a more limited excision is associated with 30-day complications, symptom improvement, and/or recurrence.

METHODS

This is a retrospective review of consecutive cases of patients who underwent surgical management of CRE between 2010 and 2018. Primary outcomes were the associations between risk factors and symptom improvement, 30-day complications, and time to recurrence. Multivariable logistic regression assessed the independent risk factors.

RESULTS

Of 2681 endometriosis cases, 142 [5.3% of total, mean age 35.4 (31.0; 39.0) years, 73.9% stage IV] underwent CRE excision (superficial partial = 66.9%, segmental = 27.5%, full thickness = 1.41%). Minor complications (14.8%) were associated with blood loss [150 (112; 288) vs. 100 (50.0; 200) mls, p = 0.046], Sigmoid involvement [45.5% vs. 12.2%, HR 5.89 (1.4; 22.5), p = 0.01], stoma formation [52.6% vs. 8.9%, HR 10.9 (3.65; 34.1), p < 0.001], and segmental resection [38.5% vs. 5.8%, HR 9.75 (3.54; 30.4), p < 0.001]. Superficial, partial-thickness resections were associated with decreased risk [(4.2% vs. 36.2%), HR 0.08 (0.02; 0.24), p < 0.001]. Factors associated with major complications (8.5%) were blood loss [250 (100; 400) vs. 100 (50.0; 200) mls, p = 0.03], open surgery [31.6% vs. 4.9%, HR 8.74 (2.36; 32.9), p = 0.001], stoma formation [42% vs. 3.3%, HR 20.3 (5.41; 90.0), p < 0.001], and segmental colectomy [28.2% vs. 0.9%, HR 34.6 (6.25; 876), p < 0.001]. Partial-thickness resection was associated with decreased risk ([.05% vs. 23.4%, HR 8.74 (2.36; 32.9), p < 0.001]. 19.1% experienced recurrence. Open surgery [5.2% vs. 21.3%, HR 0.14 (0.02; 1.05), p = 0.027] and superficial partial thickness excision [23.4% vs. 10.6%, HR 2.86 (1.08; 7.59), p = 0.027] were associated. Segmental resection was associated with decreased recurrence risk [7.6% vs. 23.5%, HR 0.27 (0.08; 0.91), p = 0.024].

CONCLUSION

Limiting resection to partial-thickness or full-thickness disc excision compared to bowel resection may improve complications but increase recurrence risk.

Simultaneous rectal neuroendocrine tumors and pituitary adenoma: A case report and review of literature

BACKGROUND

Neuroendocrine tumors (NET) are rare heterogeneous tumors that arise from neuroendocrine cells throughout the body. Acromegaly, a rare and slowly progressive disorder, usually results from a growth hormone (GH)-secreting pituitary adenoma.

CASE SUMMARY

We herein describe a 38-year-old patient who was initially diagnosed with diabetes. During colonoscopy, two bulges were identified and subsequently removed through endoscopic submucosal dissection. Following the surgical intervention, the excised tissue samples were examined and confirmed to be grade 2 NET. 18F-ALF-NOTATATE positron emission tomography-computed tomography (PET/CT) and 68Ga-DOTANOC PET/CT revealed metastases in the peri-intestinal lymph nodes, prompting laparoscopic low anterior resection with total mesorectal excision. The patient later returned to the hospital because of hyperglycemia and was found to have facial changes, namely a larger nose, thicker lips, and mandibular prognathism. Laboratory tests and magnetic resonance imaging (MRI) suggested a GH-secreting pituitary adenoma. The pituitary adenoma shrunk after treatment with octreotide and was neuroendoscopically resected via a trans-sphenoidal approach. Whole-exome sequencing analysis revealed no genetic abnormalities. The patient recovered well with no evidence of recurrence during follow-up.

CONCLUSION

18F-ALF-NOTATE PET/CT and MRI with pathological analysis can effectively diagnose rare cases of pituitary adenomas complicated with rectal NET.

Cystic Lymphangioma of Rectum-A Case Report and Review of Literature

Colorectal cystic lymphangiomas are rare benign lesions. They are characterized by the presence of either single or multi-cystic spaces lined by endothelium. Though there are multiple case reports of right and transverse colonic lymphangioma; only around 10 cases of lymphangioma of the rectum have been reported. We present a case report of rectal lymphangioma with the relevant literature review.

A novel physiologically based pharmacokinetic model of rectal absorption, evaluated and verified using clinical data on 10 rectally administered drugs

We present a physiologically based pharmacokinetic (PBPK) model simulating systemic drug concentrations following administration to the human rectum. Rectum physiology is parameterized based on literature data. The model utilizes in vitro release (IVRT) profiles from which drug mass transfer through the rectal fluid and tissue and into the systemic circulation are predicted. Due to a lack of data, rectal fluid and tissue absorption parameters are predicted either from colon absorption, with modifications relevant to rectal physiology, or optimized. The PBPK model is evaluated by simulating 29 clinical studies for 10 drugs. For 8 drugs (diazepam, diclofenac, indomethacin, naproxen, paracetamol, pentobarbital, phenobarbital and theophylline) the bias (average fold error, AFE) and precision (absolute average fold error, AAFE) of Cmax, AUC0-t and AUC0-inf simulations range from 0.87 to 2.22, indicating good agreement with observed values. For prochlorperazine and promethazine, the AFEs and AAFEs of Cmax predictions are 1.30 and 2.52, respectively. TheAUC0-t and AUC0-inf are overpredicted for both compounds(AFEs and AAFEs from 2.66 to 4.90). This results from a lack of reliable elimination data for prochlorperazine and the relevance of the IVRT profiles used in the promethazine model. The model paves the way for more mechanistic rectal drug absorption studies and virtual bioequivalence methods for rectal drug products.

Effectiveness of bladder filling control during online MR-guided adaptive radiotherapy for rectal cancer

BACKGROUND

Magnetic resonance-guided adaptive radiotherapy (MRgART) treatment sessions at MR-Linac are time-consuming and changes in organs at risk volumes can impact the treatment dosimetry. This study aims to evaluate the feasibility to control bladder filling during the rectum MRgART online session and its effectiveness on plan dosimetry.

METHODS

A total of 109 online adaptive sessions of 24 rectum cancer patients treated at Unity 1.5 T MR-Linac with a short course radiotherapy (25 Gy, 5 Gy × 5) for whom the adaptive plan was optimized and recalculated online based on the daily magnetic resonance imaging (MRI) were analysed. Patients were fitted with a bladder catheter to control bladder filling; the bladder is emptied and then partially filled with a known amount of saline at the beginning and end of the online session. A first MRI ([Formula: see text]) acquired at the beginning of the session was used for plan adaptation and the second ([Formula: see text]) was acquired while approving the adapted plan and rigidly registered with the first to ensure the appropriateness of the isodoses on the ongoing delivery treatment. For each fraction, the time interval between the two MRIs and potential bladder changes were assessed with independent metrics, and the impact on the plan dosimetry was evaluated by comparing target and organs at risk dose volume histogram cut-off points of the plan adapted on [Formula: see text] and recalculated on [Formula: see text].

RESULTS

Median bladder volume variations, DSC, and HD of 8.17%, 0.922, and 2.92 mm were registered within a median time of 38 min between [Formula: see text] and [Formula: see text]; dosimetric differences < 0.65% were registered for target coverage, and < 0.5% for bladder, small bowel and femoral heads constraints, with a p value > 0.05.

CONCLUSION

The use of a bladder filling control procedure can help ensure the dosimetric accuracy of the online adapted treatment delivered.

Application value of simultaneous multislice readout-segmented echo-planar imaging for diffusion-weighted MRI in differentiation of rectal cancer grade

OBJECTIVE

To analyze the association of apparent diffusion coefficient (ADC) values measured by readout-segmented echo-planar imaging (rs-EPI) using different simultaneous multislice (SMS) acceleration factors and the differentiation of rectal cancer grade.

MATERIALS AND METHODS

Patients with non-mucinous rectal adenocarcinoma diagnosed by biopsy (endoscope-guided biopsy or surgical resection) were retrospectively collected, and each patient underwent an MRI examination. ADC values of rs-EPI, 2 × SMS rs-EPI, and 3 × SMS rs-EPI were recorded as ADC1, ADC2, and ADC3, respectively.

RESULTS

The scanning time of 2 × SMS rs-EPI was 60 s, 56.2% shorter than 137 s of rs-EPI sequence, while that of 3 × SMS rs-EPI was 51 s, 72.8% less than that of rs-EPI time. The ADC value of the three groups dropped with the decrease in cancer grade (p < 0.05). The AUC values of ADC1, ADC2, and ADC3 in predicting highly differentiated rectal cancer were 0.74, 0.729, and 0.687, respectively. The difference in AUC values between ADC1 and ADC2 was not statistically significant (p = 0.889).

DISCUSSION

SMS technology with an acceleration factor of 2 could be applied clinically to evaluate the pathological differentiation of rectal cancer grade.

Inferior mesenteric artery ligation level in rectal cancer surgery: still no answer-a systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis is to summarize the current scientific evidence regarding the impact of the level of inferior mesenteric artery (IMA) ligation on post-operative and oncological outcomes in rectal cancer surgery.

METHODS

We conducted a systematic review of the literature up to 06 September 2022. Included were RCTs that compared patients who underwent high (HL) vs. anterior (LL) IMA ligation for resection of rectal cancer. The literature search was performed on Medline/PubMed, Scopus, and the Web of Science without any language restrictions. The primary endpoint was overall anastomotic leakage (AL). Secondary endpoints were oncological outcomes, intraoperative complications, urogenital functional outcomes, and length of hospital stay.

RESULTS

Eleven RCTs (1331 patients) were included. The overall rate of AL was lower in the LL group, but the difference was not statistically significant (RR 1.43, 95% CI 0.95 to 2.96). The overall number of harvested lymph nodes was higher in the LL group, but the difference was not statistically significant (MD 0.93, 95% CI - 2.21 to 0.34). The number of lymph nodes harvested was assessed in 256 patients, and all had a laparoscopic procedure. The number of lymph nodes was higher when LL was associated with lymphadenectomy of the vascular root than when IMA was ligated at its origin, but there the difference was not statistically significant (MD - 0.37, 95% CI - 1.00 to 0.26). Overall survival at 5 years was slightly better in the LL group, but the difference was not statistically significant (RR 0.98, 95% CI 0.93 to 1.05). Disease-free survival at 5 years was higher in the LL group, but the difference was not statistically significant (RR 0.97, 95% CI 0.89 to 1.04).

CONCLUSIONS

There is no evidence to support HL or LL according to results in terms of AL or oncologic outcome. Moreover, there is not enough evidence to determine the impact of the level of IMA ligation on functional outcomes. The level of IMA ligation should be chosen case by case based on expected functional and oncological outcomes.

Detection of mpox virus in ambient air in a sexual health clinic

Although transmitted mainly through direct (sexual) contact, mpox virus (MPXV) can be detected in ambient air. We explored the use of air sampling for diagnosis or (genomic) surveillance of mpox in a sexual health clinic. For six out of six patients who were infected with MPXV, all four of our ambient air PCR tests were positive. For 14 uninfected patients, PCR was positive in three ambient air samples, albeit with higher cycle threshold (Ct) values. Genomic sequencing of samples from two positive patients showed matching sequences between air and clinical samples.

Primary rectal mucosa-associated lymphoid tissue lymphoma treated with only endoscopic submucosal dissection: A case report

BACKGROUND

Mucosa-associated lymphoid tissue (MALT) lymphoma is a distinct subtype of non-Hodgkin B cell lymphoma that mostly involves the gastrointestinal tract. The stomach is the most commonly affected site whereas colorectal involvement occurs very rarely. Given its rarity, the management and clinical outcome of colorectal MALT lymphoma are not well established yet.

CASE SUMMARY

From the superficial capillary bed in the lower rectum. Endoscopic ultrasonography showed homogenous hypoechoic lesions in the deep mucosal layer. Endoscopic submucosal dissection (ESD) was done for accurate histologic diagnosis and treatment and both the rectal lesions were completely removed en bloc and subsequently diagnosed as primary rectal MALT lymphoma. Herein, we report a case of primary rectal MALT lymphoma in a 68-year-old woman that was treated by only ESD, and the 12-month follow-up revealed no tumour recurrence.

CONCLUSION

These results of our case and previous reports suggest that endoscopic resection alone may be a feasible and safe treatment for primary colorectal MALT lymphoma and allows organ preservation.

Leiomyosarcoma of the lower rectum managed by radiotherapy and surgery: A case report and review of literature

Rectal leiomyosarcoma is a very rare entity. Surgery is the main treatment, but the place of radiation therapy remains unclear. A 67-year-old woman was referred for a few-weeks' history of bleeding and anal pain intensified during defecation. Pelvic magnetic resonance imaging (MRI) showed a rectal lesion and biopsies revealed a leiomyosarcoma of the lower rectum. She was free of metastasis on computed tomography imaging. The patient refused radical surgery. After discussion by a multidisciplinary team, the patient received pre-operative long-course radiotherapy followed by surgery. The tumor was treated with 50Gy delivered in 25 fractions, within 5 weeks. The aim of radiotherapy was local control, allowing organ-preservation. Four weeks after radiation therapy, organ-preservation surgery could be performed. She had no adjuvant treatment. At 38-months follow-up, she had no local recurrence. However, distant recurrence (lung, liver, and bone) was detected 38 months after the resection and was managed by intra-venous doxorubicin 60mg/m² and dacarbazine 800mg/m² every 3 weeks. The patient was in a stable condition for nearly 8 months. The patient died 4 years and 3 months after the diagnosis.

Multiple distant metastases arising from a single, low-grade rectal neuroendocrine tumor: an autopsy case report

BACKGROUND

Rectal neuroendocrine neoplasms are rare epithelial neoplasms of the rectum. The incidence of these tumors has increased over the past decades. However, many questions remain unanswered regarding their clinicopathology, including the possible mechanisms in which these tumors may grow and metastasize.

CASE PRESENTATION

In this case report, we report the findings of an autopsy of a 65-year-old Japanese woman diagnosed with multiple liver metastases from a single, low-grade rectal neuroendocrine tumor. The diagnosis was made in late 2018 to early 2019, and subsequently the patient underwent several rounds of standard chemotherapy. However, due to unfavorable side effects, she opted for palliative care at our hospital instead from December 2020. The patient's condition was generally stable for the next 17 months, but in May 2022, she was hospitalized for increased abdominal pain. Despite enhanced pain control therapy, she eventually passed away. An autopsy was conducted to determine the exact cause of death. The primary rectal tumor was found to be small, but showed strong histological evidence of venous invasion. Metastases in the liver, pancreas, thyroid gland, adrenal glands, and vertebrae were also present. On the basis of the histological evidence obtained, we deduced that the tumor cells may have mutated and gained multiclonality as they spread vascularly to the liver, contributing to the distant metastases.

CONCLUSIONS

The results from this autopsy may provide an explanation for the possible mechanism by which small, low-grade rectal neuroendocrine tumors metastasize.

Incidental cancer in colectomy specimens from patients with familial adenomatous polyposis: single centre experience and literature review

BACKGROUND

Since cancer development is inevitable in patients with familial adenomatous polyposis (FAP), we aimed to determine the incidence of incidental malignancy in prophylactic colectomy specimens.

METHODS

The files of patients who underwent prophylactic surgery for FAP between 2010 and 2020 were retrospectively reviewed. The incidence of incidental malignancy in histopathological specimens was examined and a comprehensive literature review was made.

RESULTS

Fifty-five patients were included in the study, of whom 30 patients had a diagnosis of primary malignancy. Prophylactic colectomy was performed on 25 patients. The pathology results indicated that the specimens were benign in 12 patients (48%) and revealed carcinoma in situ in 11 patients (44%). Incidental malignancy was detected in 2 patients (8%). In the literature review, there were 243 patients who underwent prophylactic colectomy and incidental cancer was detected in 25 patients (10.3%) with the stages of 1 (7.4%), 2 (2.1%), and 3 (0.8%), respectively.

CONCLUSIONS

Incidental cancer is not rare in patients who have undergone prophylactic colectomy for FAP. Hopefully. they are usually at early stages and unexpected advanced cancers are seen rarely.

Clinical outcomes and risk factors associated with poor prognosis after endoscopic resection of 10-20 mm rectal neuroendocrine tumors: a multicenter, retrospective study of 10-year experience

BACKGROUND

The efficacy of endoscopic resection for of 10-20 mm rectal neuroendocrine tumor (NET) remains controversial. We aimed to evaluate the clinical outcomes and risk factors associated with poor prognosis after endoscopic resection of 10-20 mm rectal NET and to determine the optimal treatment.

METHODS

Patients who underwent endoscopic resection for rectal NET in four tertiary hospitals were enrolled, and data on with the clinical outcomes and risk factors related to poor prognosis were retrospectively analyzed.

RESULTS

A total of 105 patients who underwent endoscopic submucosal resection (ESD; n = 65, 61.9%), modified endoscopic mucosal resection (mEMR; n = 31, 29.5%), and conventional EMR (cEMR; n = 9, 8.6%) were enrolled. The mean follow-up period was 41.2 ± 21.9 months. In the morphologic findings, the mean diameter was 11.6 mm (range 10-19); the shape was sessile (50.5%) and mixed type (49.5%), and surface depression was observed in 41.9% of patients. In the histologic findings, 87.6% of patients had G1 and 12.4% G2 tumor grade, and 3.8% of patients had lymphovascular invasion. The overall en bloc and histologically complete (R0) resections were 99.1% and 76.2%, respectively. cEMR was a less-frequently developed R0 resection. In the univariate and multivariate analyses for R0 resection, only surface depression was significantly associated. Regional or distant organs metastasis during follow-up developed in three patients (2.9%) and was significantly associated with female sex, redness, G2 tumor grade, and non-ESD methods.

CONCLUSION

Patients who underwent endoscopic resection of 10-20 mm rectal NET had good prognosis; therefore, endoscopic resection can be considered as the first-line treatment, particularly for 10-14 mm rectal NET. However, the risk factors, such as female sex, redness, G2 tumor grade and non-ESD methods, were associated with regional or distant metastases during follow-up. Therefore, patients with these risk factors should be carefully monitored.

Long-Term Outcomes of the Excluded Rectum in Crohn's Disease: A Multicenter International Study

BACKGROUND

Many patients with Crohn's disease (CD) require fecal diversion. To understand the long-term outcomes, we performed a multicenter review of the experience with retained excluded rectums.

METHODS

We reviewed the medical records of all CD patients between 1990 and 2014 who had undergone diversionary surgery with retention of the excluded rectum for at least 6 months and who had at least 2 years of postoperative follow-up.

RESULTS

From all the CD patients in the institutions' databases, there were 197 who met all our inclusion criteria. A total of 92 (46.7%) of 197 patients ultimately underwent subsequent proctectomy, while 105 (53.3%) still had retained rectums at time of last follow-up. Among these 105 patients with retained rectums, 50 (47.6%) underwent reanastomosis, while the other 55 (52.4%) retained excluded rectums. Of these 55 patients whose rectums remained excluded, 20 (36.4%) were symptom-free, but the other 35 (63.6%) were symptomatic. Among the 50 patients who had been reconnected, 28 (56%) were symptom-free, while 22(44%) were symptomatic. From our entire cohort of 197 cases, 149 (75.6%) either ultimately lost their rectums or remained symptomatic with retained rectums, while only 28 (14.2%) of 197, and only 4 (5.9%) of 66 with initial perianal disease, were able to achieve reanastomosis without further problems. Four patients developed anorectal dysplasia or cancer.

CONCLUSIONS

In this multicenter cohort of patients with CD who had fecal diversion, fewer than 15%, and only 6% with perianal disease, achieved reanastomosis without experiencing disease persistence.

Surgical approaches to colonic and rectal anastomosis: systematic review and meta-analysis

PURPOSE

Postoperative complications after a colonic and rectal surgery are of significant concern to the surgical community. Although there are different techniques to perform anastomosis (i.e., handsewn, stapled, or compression), there is still no consensus on which technique provides the least number of postoperative problems. The objective of this study is to compare the different anastomotic techniques regarding the occurrence or duration of postoperative outcomes such as anastomotic dehiscence, mortality, reoperation, bleeding and stricture (as primary outcomes), and wound infection, intra-abdominal abscess, duration of surgery, and hospital stay (as secondary outcomes).

METHODS

Clinical trials published between January 1, 2010, and December 31, 2021, reporting anastomotic complications with any of the anastomotic technique were identified using the MEDLINE database. Only articles that clearly defined the anastomotic technique used, and report at least two of the outcomes defined were included.

RESULTS

This meta-analysis included 16 studies whose differences were related to the need of reoperation (p < 0.01) and the duration of surgery (p = 0.02), while for the anastomotic dehiscence, mortality, bleeding, stricture, wound infection, intra-abdominal abscess, and hospital stay, no significant differences were found. Compression anastomosis reported the lowest reoperation rate (3.64%) and the handsewn anastomosis the highest (9.49%). Despite this, more time to perform the surgery was required in compression anastomosis (183.47 min), with the handsewn being the fastest technique (139.92 min).

CONCLUSIONS

The evidence found was not sufficient to demonstrate which technique is most suitable to perform colonic and rectal anastomosis, since the postoperative complications were similar between the handsewn, stapled, or compression techniques.

Development of novel prediction models for nodal and distant metastasis in G1 and G2 colorectal neuroendocrine tumors

PURPOSE

We aimed to construct novel nomograms for nodal and distant metastasis for patients with G1 and G2 colorectal neuroendocrine tumors (NETs).

METHODS

A training set and validation set were obtained by including G1 and G2 colorectal NET patients from the Surveillance, Epidemiology, and End Results database and the Cancer Hospital Chinese Academy of Medical Science, respectively. The area under curve (AUC) values under receiver operating characteristic (ROC) curves, calibration plots, and the Hosmer‒Lemeshow tests were used to evaluate the discriminability and calibration of nomograms.

RESULTS

In total, 3690 and 172 patients were included in the training set and validation set, respectively. Tumor size, location, and T stage were included in the nomogram predicting nodal metastasis. The AUC values of the nomogram were 0.972 (95% confidence interval (CI): 0.964-0.980) and 0.897 (95% CI: 0.846-0.948) in the training set and validation set, respectively. The calibration plots and Hosmer‒Lemeshow test for the training set (P = 0.999) and validation set (P = 0.537) showed good model calibration. Tumor size, T stage, and N stage were incorporated into the nomogram predicting distant metastasis. The ROC curves demonstrated desirable discrimination both in the training set (AUC = 0.938 (95% CI: 0.921-0.954)) and validation set (AUC = 0.938 (95% CI: 0.890-0.988)). The calibration curves and Hosmer‒Lemeshow test indicated acceptable model calibration both in the training set (P = 0.908) and validation set (P = 0.722).

CONCLUSION

The proposed nomograms may be used as a reliable tool to predict the nodal and distant metastasis in G1 and G2 colorectal NETs.

Signet ring cell carcinoma of the rectal stump in a known ulcerative colitis patient

Colorectal carcinoma (CRC) is the third most commonly diagnosed cancer worldwide and is the second most common cause of cancer-related deaths. However, the Omani population shares the major burden as the most prevalent carcinoma. The disease is comparatively higher in males than females. Patients with pre-existing risk factors, including inflammatory bowel disease, are at increased risk of developing neoplasia. Among the various histopathological subtypes of adenocarcinoma in the rectum, signet ring cell carcinoma is the rarest and accounts for approximately 1% of the cases. Given the aggressive nature of this tumor, advanced presentation, stage, and poor prognosis, regular endoscopic surveillance is essential. Hereby, we report a rare case of signet ring cell carcinoma arising in the rectal stump in an already diagnosed and operated patient of Ulcerative colitis.

A rare case of a superficial squamous cell carcinoma (so-called cloacogenic carcinoma) of the rectum

A rare case of a squamous cell carcinoma (so-called cloacogenic carcinoma) showing extensive superficial spread to the rectum is presented. A 69-year-old woman had undergone colonoscopy for annual check-up, and a whitish, flat lesion with a central depressed area, 20 mm in size, was identified in the lower rectum. Narrow-band imaging with magnifying observation showed abnormal microvessels without the intrapapillary capillary loop patterns. Endoscopically, the margin of the lesion was unclear. Biopsy was performed, and a histological diagnosis of transitional cell carcinoma was made. Computed tomography showed no evidence of involvement of adjacent organs, lymph nodes or distant sites. Cystoscopy found no abnormality in the bladder mucosa. Owing to difficulty diagnosing this tumor accurately, local excision with transanal endoscopic microsurgery was performed. Cloacogenic carcinoma with submucosal invasion was diagnosed. A human papilloma virus (HPV) polymerase chain reaction test was positive. Judging from the histological findings and the positive HPV test, we hypothesis that the tumor was likely arising from the anal transitional zone with marked superficial spread to the rectum. Clinicians should keep in mind that this variant of squamous cell carcinoma may occur in the rectum, even if no endoscopic findings are seen in the anal transitional zone.

Excision of Deep Rectovaginal Endometriosis Nodules with Large Infiltration of Both Rectum and Vagina: What Is a Reasonable Rate of Preventive Stoma? A Comparative Study

STUDY OBJECTIVE

To compare postoperative complications and rectovaginal fistula rate in women undergoing excision of large rectovaginal endometriosis requiring concomitant excision of rectum and vagina during 2 time periods with differing policies for preventive stoma confection.

DESIGN

Retrospective before-and-after comparative cohort study on data prospectively recorded in a database. Patients managed from September 2018 to March 2020 (first period) were compared with those managed from April 2020 to June 2022 (second period).

SETTING

Endometriosis Institute.

PATIENTS

One hundred sixty-eight patients presenting with deep endometriosis infiltrating the rectum and vagina, with lesions more than 3 cm in diameter during 2 consecutive time periods with differing policies regarding use of preventive stoma.

INTERVENTIONS

Rectal disc excision or colorectal resection, concomitantly with large vaginal excision.

MEASUREMENTS AND MAIN RESULTS

A total of 87 and 81 women received surgery during the first and the second period, respectively, during which the rate of preventive stoma was, respectively, 32.2% and 8.6%. Deep rectovaginal nodule characteristics were comparable. The mean height (SD) of rectal sutures after disc excision and colorectal resection were, respectively, 6.5 cm (2.3 cm) and 7.2 cm (3.8 cm). Rectovaginal fistula was recorded in 17 patients, corresponding to an overall rate of 10.1%. The rates of rectovaginal fistula in the group of patients with and without preventive stoma, regardless of the period in which surgery was performed, were 11.4% and 9.8%, respectively (p = .76). The rates of fistula recorded during the first and the second period were, respectively, 9.2% and 11.1% (p = .80), and that of overall early main complications were 31% and 29.6% (p = .84). Regression logistic model identified an independent relationship between smoking and rectovaginal fistula (adjusted odds ratio [OR] 3.9, 95% confidence interval [CI] 1.1-14) after adjustment for the period (adjusted OR 1.4, 95% CI 0.4-4.9 related to the second period), stoma confection (adjusted OR 1.8, 95% CI 0.5-7.1 related to stoma confection), robotic surgery (adjusted OR 1.7, 95% CI 0.3-10.1 related to robotic assistance), and type of rectal surgery (adjusted OR 0.4, 95% CI 0.1-1.4 related to disc excision when compared with colorectal resection).

CONCLUSION

No statistically significant differences were found concerning risk of rectovaginal fistula in women with rectovaginal endometriosis requiring large rectal and vaginal excision after a decision to no longer routinely perform preventive stoma.

Sensory brain activation during rectal balloon distention: a pilot study in healthy volunteers to assess safety and feasibility at 1.5T

OBJECTIVE

Although increasing evidence suggests a central mechanism of action for sacral neuromodulation, the exact mechanism remains unclear. We set up a scanning paradigm to measure brain activation related to various stages of rectal filling using rectal balloon distention.

MATERIALS AND METHODS

Six healthy volunteers underwent rectal balloon distention during MRI scanning at a 1.5T scanner with a Tx/Rx head coil. MR images were collected at four levels of distention: empty balloon (EB), first sensation volume (FSV), desire to defecate volume (DDV), maximum tolerable volume (MTV). Data were analyzed using BrainVoyager 20.4. Whole brain and ROI-based fixed-effects general linear model analyses were performed on the fMRI time-course data from all participants.

RESULTS

Rectal filling until FSV evoked the most blood-oxygen-level-dependent responses in several clusters throughout the cortex, followed by the responses evoked by rectal filling until DDV. Interestingly, rectal filling until MTV evoked negative responses compared to baseline throughout the cortex. No negative side effects were found.

DISCUSSION

This study shows that a standardized paradigm for functional MRI combined with rectal filling is feasible and safe in healthy volunteers and is ready to be used in fecal incontinent patients to assess whether their brain activity differs from healthy controls.

Disk Excision Using End-to-End Anastomosis Circular Stapler for Deep Endometriosis of the Rectum: A 492-Patient Continuous Prospective Series

STUDY OBJECTIVE

To report a large series including women managed by disk excision using end-to-end anastomosis (EEA) circular transanal stapler to assess the feasibility of the technique, the features of nodules suitable for removal by disk excision, and the rate of major early complications.

DESIGN

Retrospective study on data prospectively recorded in 2 databases.

SETTING

Two tertiary referral centers.

PATIENTS

A total of 492 patients undergoing surgery for rectal endometriosis from May 2011 to June 2022.

INTERVENTIONS

Rectal disk excision using the EEA stapler.

MEASUREMENT AND MAIN RESULTS

Disk excision using EEA was performed in 492 patients (24.2%) of 2,029 women receiving surgery for deep endometriosis infiltrating the rectum during the 11-year study period. Deep endometriosis involved low rectum in 11% and mid rectum in 55.3%. The diameter of rectal nodules exceeded 3 cm in 65.9%. Mean operative time was 2 hours, mean diameter of rectal patches removed was 41 ± 11 mm, and the mean rectal suture height was 9.2 ± 5.5 cm. The presence of microscopic foci on the edges of rectal patches was identified in 30.2% of cases. Rectal fistula was recorded in 20 patients (4%). The distance from the anal verge was significantly lower in patients with fistula than women with no fistula (5.9 ± 2 cm vs 9.2 ± 5.6 cm, p = .027). Follow-up ranged from 1 to 120 months, with a median value of 36 months. Magnetic resonance imaging in 3 patients during follow-up revealed a recurrent nodule infiltrating the previous stapled line (0.6%) after a postoperative delay of, respectively, 36, 48, and 84 months.

CONCLUSION

Disk excision using the EEA stapler is suitable in nodules >3 cm if surgeons ensure deep shaving of the rectum, to allow complete inclusion of the shaved area into the stapler jaws. Postoperative rectal recurrences seem incidental, whereas bowel leakage rate is comparable with that after colorectal resection. This technique is suitable in almost a quarter of patients managed for rectal endometriosis nodules and is therefore a valuable technique that warrants more widespread use.

Influence of neo-adjuvant radiotherapy on the intestinal microbiota of rectal cancer patients

PURPOSE

Neo-adjuvant radiotherapy (NART) is a widely used pre-surgery radiotherapy for rectal cancer patients. Although NART is effective in reducing tumor burden before surgery, it may cause dysbiosis of intestinal microbiota. The intestinal microbiota shapes tumor inflammatory environment and influences cancer progression. However, how NART remodels the microbiota and how the microbiota affects therapeutic efficacy has been largely elusive. This study aimed to reveal the details of how NART affects the intestinal microbiota in patients with rectal cancer.

METHODS

Rectal cancer patients who received NART were recruited into the study, and their healthy family members on the same diet served as controls. Stool samples from five rectal cancer patients (28 in total) and five healthy individuals (16 in total) were collected for intestinal microbiota analysis by 16S rRNA gene amplicon sequencing. Samples from patients were divided into earlier- and later-NART according to the number of NART.

RESULTS

NART did not significantly affect the α diversity of intestinal microbiota. However, the abundance of bacterial genera associated with cancer progression tended to decrease in later-NART patients. More importantly, a variety of oral pathogenic bacteria were enriched in the intestine of later-NART patients. NART also affected functional pathways associated with the microbiota in DNA repair, metabolism, and bacterial infection.

CONCLUSION

NART significantly altered the microbiota composition and function in rectal cancer patients, and some oral pathogens were found to translocate to the intestine. This is the first report to study the effect of NART on intestinal microbiota in patients with rectal cancer, exploring the importance of intestinal microbiota during the process of NART.

Rectal stimulation with prebiotics and probiotics before ileostomy reversal: a study protocol for a randomized controlled trial

BACKGROUND

Ileostomy closure is associated with a high rate of postoperative morbidity, and adynamic ileus is the most common complication, with an incidence of up to 32%. This complication is associated with delayed initiation of oral diet intake, abdominal distention, prolonged hospital stay, and more significant patient discomfort. The present study aims to evaluate the rectal stimulus with prebiotics and probiotics before ileostomy reversal.

METHODS

This is a protocol study for an open-label randomized controlled clinical trial. Ethical approval was received (CAAE: 56551722.6.0000.0071). The following criteria will be used for inclusion: adult patients with rectal cancer stages cT3/4Nx or cTxN+ that underwent loop protection ileostomy, patients treated with neoadjuvant chemoradiotherapy, and patients who underwent laparoscopic or robotic total mesorectal excision. Patients will be randomized to one of two groups. The intervention group (with rectal stimulus): the patients will apply 500 ml of saline solution with 6 g of Simbioflora® rectally, once a day, for 15 days before ileostomy closure. The control group (without rectal stimulation): the patients will close the ileostomy with no previous rectal stimulus. The primary outcomes will be the adynamic ileus (need for postoperative nasogastric tube insertion; nausea/vomiting; or intolerance to oral feedings within the first 72 h) and intestinal transit (time to first evacuation/flatus).

RESULTS

The patient's enrollment starts in January 2023. We expect to finish in July 2025.

DISCUSSION

The findings of this randomized clinical study may have important implications for managing patients undergoing ileostomy reversal.

TRIAL REGISTRATION

This study is registered in the Brazilian Trial Registry (ReBEC) under RBR-366n64w. Registration date: 19/07/2022.