Machine learning and machine teaching in histopathology

An artificial intelligence (AI) platform was trained by a consultant histopathologist to classify whole slide images (WSIs) of large bowel biopsies. Six medical students viewed WSIs of five large bowel biopsy cases and assigned the WSIs to one of the nine diagnostic categories. Then the students compared their answers with those generated by the AI. This training was repeated for a total of six rounds of five cases, and the accuracy of the students was recorded for each round. Each case had one or more WSIs. The student with the best final accuracy was asked to describe the morphological features that they had deduced. All the students improved during their training, from a mean accuracy of 13.7% in the first round to a mean accuracy of 77.1% in the sixth round (p = 0.0011). The student-deduced diagnostic features were mainly accurate. Some students learned more quickly than others.

Colonic involvement in inflammatory bowel diseases: spotlight on the role of magnetic resonance enterography

The large bowel can be affected by inflammatory bowel diseases, namely ulcerative colitis and Crohn's disease, with the latter occurring either as a unique localization or in conjunction with simultaneous ileal involvement. The differential diagnosis among these conditions is challenging and relies on clinical symptoms, laboratory tests and endoscopy with biopsy. However, as these features can overlap, a conclusive diagnosis is not always achievable, and the underlying cause remains indeterminate. Currently, endoscopy is the reference standard for colonic assessment, although its invasiveness limits its use and repetition within a short timeframe. Magnetic Resonance Enterography is a non-invasive, radiation-free technique that has been extensively and effectively employed in the intestinal evaluation of patients with Crohn's disease in recent years. Although the main goal of this technique is generally focused on evaluating small bowel loops, it can also provide important information about the large bowel if an adequate fulfillment by the oral contrast medium is achieved. The purpose of this work is, therefore, to put emphasis on the potential role of Magnetic Resonance Enterography in assessing the large bowel. In fact, this imaging modality is capable of providing valuable information for comprehensive staging and follow-up of inflammatory bowel diseases within the large bowel, thus complementing the clinical picture and the endoscopic features in the context of a differential diagnosis.

Artificial intelligence-based triage of large bowel biopsies can improve workflow

Background

Large bowel biopsies are one of the commonest types of biopsy specimen. We describe a service evaluation study to test the feasibility of using artificial intelligence (AI) to triage large bowel biopsies from a reporting backlog and prioritize those that require more urgent reporting.

Methods

The pathway was developed in the UK by National Health Service (NHS) laboratory staff working in a medium-sized general hospital.   The AI platform was interfaced with the slide scanner software and the reporting platform's software, so that pathologists could correct the AI label and reinforce the training set as they reported the cases.

Results

he AI classifier achieved a sensitivity of 97.56% and specificity of 93.02% for the case-level-diagnosis of neoplasia (adenoma and adenocarcinoma) and for an AI diagnosis of any significant pathology (i.e., adenomas, adenocarcinomas, inflammation, hyperplastic polyps, and sessile serrated lesions) sensitivity was 95.65% and specificity 92.96%. The automated AI diagnostic classification pathway took approximately 175 s per slide to download and process the scanned whole slide image (WSI) and return an AI diagnostic classification. Biopsies with an AI diagnosis of neoplasia or inflammation were prioritized for reporting while the remainder followed the routine reporting pathway. The AI triaged pathway resulted in a significantly shorter reporting turnaround time for pathologist verified neoplastic cases (P < 0.001) and inflammation (P < 0.05). The project's costs amounted to  £14800, excluding laboratory staff salaries. More time and resources were spent on developing the interface between the AI platform and laboratory IT systems than on the development of the AI platform itself.

Conclusions

NHS laboratory staff were able to implement an AI solution to accurately triage large bowel biopsies into several diagnostic classes and this improved reporting turnaround times for cases with neoplasia or with inflammation.

Large intestine as content of congenital inguinal hernia: A case report of intestinal obstruction

Introduction and importance

Hernias containing appendix, caecum and transverse colon are uncommon in contrast with usual inguinal hernias containing small intestine. The patient usually presents with inguinoscrotal swelling.

Case presentation

We present a case of a 2 months old male child presented with inguinoscrotal swelling, vomiting with abdominal distention. On Ultrasonography (USG) of the scrotum, protrusion of the abdominal cavity contents through the right inguinal canal into the scrotum of approximately 3.4 cm × 0.7 cm was found which indicates right inguinal hernia. On the opening of the hernia sac during surgical management, the appendix, caecum and transverse colon were lying inside the hernia sac. Open Herniotomy was performed and the abdomen was closed in layers. Postoperative period of the patient was uneventful.

Discussion

Congenital inguinal hernia in the child occurs mostly due to persistent processus vaginalis. History and clinical examination reveals the appearance of lump in the inguinal region or scrotum. Preoperative Ultrasonography can be used to supplement the physical examination and increase the accuracy of its diagnosis. Although the laparoscopic approach is increasingly used nowadays, open hernia repair is preferred in young children.

Conclusion

Appendix, caecum and transverse colon are unusual contents of an inguinal hernia. Open herniotomy combined with relieving of the intestinal obstruction is the treatment of choice in young children.

Better response to low FODMAP diet in disorders of gut-brain interaction patients with pronounced hydrogen response to a nutrient challenge test

BACKGROUND AND AIM

Previous studies have shown a reduction of gastrointestinal symptoms in irritable bowel syndrome (IBS) patients following a low FODMAP diet (LFD). It remains unknown which disorders of gut-brain interaction (DGBI) patients would benefit most from LFD. We aimed to analyze LFD response regarding a preceding nutrient challenge test (NCT).

METHODS

Data of 110 consecutive DGBI patients undergoing NCT and LFD between August 2015 and August 2018 were analyzed retrospectively. LFD response was assessed by changes in IBS Symptom Severity Score (IBS-SSS). In mixed-effects linear regression models, the impact of hydrogen values and abdominal symptoms during NCT, performed with 30-g lactulose and 400-mL liquid test meal, on IBS-SSS changes were analyzed.

RESULTS

Low FODMAP diet induced a significant IBS-SSS reduction of 78 points (95% confidence interval [CI] 50-96; P < 0.001). Patients with higher NCT-induced hydrogen increase during proximal intestinal transit had a significantly better LFD response (-66 IBS-SSS reduction per 10-ppm hydrogen increase, 95% CI -129 to -4, P = 0.045). Additionally, the higher the NCT-induced maximum hydrogen increase during mid-distal and distal intestinal transit, the better are the responses to LFD (-6 IBS-SSS per 10-ppm maximum delta hydrogen, 95% CI -11 to -1, P = 0.040). There was no association of LFD response with abdominal symptom generation during NCT.

CONCLUSIONS

Our study is the first one analyzing and demonstrating significant associations between NCT results and LFD response. These findings are of high clinical importance, as they identify a subgroup of DGBI patients that may profit most from a restrictive LFD as first-line therapy.

Intestinal metastasis from breast cancer: Presentation, treatment and survival from a systematic literature review

BACKGROUND

Intestinal metastases from breast cancer (BC) arerare; available data depend mainly on case reports and case series.

AIM

To conduct a review of the literature regarding presentation, diagnosis, treatment and survival of patients with intestinal metastasis from BC.

METHODS

We identified all articles that described patients with intestinal metastasis (from duodenum to anum) from BC using MEDLINE (1975 to 2020) and EMBASE (1975 to 2020) electronic databases.

RESULTS

We found 96 cases of intestinal metastasis of BC. Metastasization involved large bowel (cecum, colon, sigmoid, rectum) (51%), small bowel (duodenum, jejunum, ileum) (49%), and anum (< 1%). Median age of patients was 61-years. The most frequent histology was infiltrating lobular carcinoma followed by infiltrating ductal carcinoma. In more than half of patients, the diagnosis was made after the diagnosis of BC (median: 7.2 years) and in many cases of emergency, for bowel obstruction, bleeding or perforation. Diagnosis was achieved through endoscopy, radiological examination or both. In most of the cases, patients underwent surgery with or without systemic therapies. Survival of patients included in this review was available in less than 50% of patients and showed an overall median of 12 mo since diagnosis of the intestinal metastasis.

CONCLUSION

Although, intestinal metastases of BC are considered a rare condition, clinicians should consider the possibility of intestinal involvement in case of abdominal symptoms even in acute setting and many years after the diagnosis of BC, especially in patients with a histology of lobular carcinoma.

Magnetic Resonance Imaging of the Anal Region: Clinical Applications

Over the past years, magnetic resonance imaging (MRI) has become a cornerstone in evaluating anal canal and adjacent tissues due to its safeness, the three-dimensional and comprehensive approach, and the high soft-tissue resolution. Several diseases arising in the anal canal can be assessed through MRI performance, including congenital conditions, benign pathologies, and malignancies. Good knowledge of the normal anatomy and MRI technical protocols is, therefore, mandatory for appropriate anal pathology evaluation. Radiologists and clinicians should be familiar with the different clinical scenarios and the anatomy of the structures involved. This pictorial review presents an overview of the diseases affecting the anal canal and the surrounding structures evaluated with dedicated MRI protocol.

Large bowel obstruction secondary to schistosomiasis-related colonic stricture

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Schistosomiasis can manifest as non-obstructive polypoid lesions due to deposition of schistosomal eggs.

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Obstructive lesions, such as fibrotic strictures, secondary to the infectious sequelae of schistosomiasis are rare.

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Although schistosomiasis can be diagnosed on imaging and laboratory tests, there is no conclusive method of ruling out a malignancy.

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Praziquantel is a safe and effective treatment for schistosomiasis, and prevents future sequela of the parasitic infection.

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Surgical resection provides definitive treatment resulting in symptom resolution while ruling out a neoplastic etiology.

Introduction

Intestinal involvement of schistosomiasis uncommonly involves the formation of non-obstructive polypoid lesions; however, obstructing fibrotic stenoses and strictures secondary to chronic infection are extremely rare with only nine reported cases in the literature.

Presentation of case

An 85-year-old Southeast Asian female originating from the Philippines presents with a one-day history of obstructive symptoms in the setting of chronic constipation over the past four months. Subsequent CT imaging and colonoscopy biopsy revealed a nodular cecal mural wall thickening with chronic inflammation and a single Schistosoma egg. Despite treatment with praziquantel, and medical optimization the patient did not improve. Additionally, a malignancy as the underlying cause of obstruction could not be ruled out as such, she had a right hemicolectomy. Final pathology confirmed the diagnosis of intestinal submucosal schistosomiasis causing fibrotic stenosis.

Conclusion

Obstructing lesions including fibrotic stenoses secondary to Schistosomiasis infection can be managed safely with medical co-morbidity optimization when possible, treatment with Praziquantel and surgical resection of the involved area of colon. Given the risk of malignancy and the inability to clinically distinguish between infectious and neoplastic processes, surgical management is recommended.

Diagnostic flow-chart to identify bowel involvement in patients with stage IIIC-IV ovarian cancer: Can laparoscopy improve the accuracy of CT scan?

OBJECTIVE

This study investigates the diagnostic power of CT scan combined with exploratory laparoscopy (EXL) at identifying large bowel involvement in patients with stage IIIC-IV primary Epithelial Ovarian Cancer (EOC) by comparing with the macroscopic surgical findings at laparotomy.

METHODS

All patients with FIGO Stage IIIC-IV EOC who had Visceral Peritoneal Debulking (VPD) were included in the study. Results of CT scan, EXL and laparotomy (LPT) with regards to the bowel involvement were prospectively recorded in an ad hoc study form. Setting LPT findings as the gold standard, positive and negative predictive value (PPV/NPV), sensitivity, specificity and accuracy of CT and EXL were calculated. In addition, the diagnostic power of the combination CT scan + EXL was investigated.

RESULTS

Ninety-four out of 177 patients (53.2%) had a bowel resection during VPD. CT-scan alone had sensitivity, specificity, PPV, NPV and accuracy of 56.7%, 72.4%, 70.8%, 58.5% and 63.8% respectively. EXL alone 84.4%, 93.8%, 93.8%, 84.3%, 88.8%. CT combined with EXL detected bowel involvement with a sensitivity, specificity, PPV, NPV and accuracy of 87.5%, 70.4%, 77.8%, 82.6% and 79.6% and respectively. The combined tests showed a statistically significant improvement vs. CT scan alone (p < 0001) in sensitivity, NPV and accuracy, with non-significant difference in specificity and PPV.

CONCLUSIONS

CT-scan alone shows a limited diagnostic power at detecting large bowel involvement in patients with stage IIIC-IV EOC. The combination of CT scan with EXL increases the diagnostic power and enables to appropriately plan the bowel resection and consent the patients.

[Large bowel ganglioneuromatosis associated with neurofibromatosis type 1]

Gastrointestinal tract ganglioneuromatosis is a rare condition, which is isolated or included in a syndromique disease. Multiple endocrine neoplasia type 2 is the most frequently associated syndrome. Association with type 1 neurofibromatosis has also been established, but much rarely. We report the case of large bowel ganglioneuromatosis found incidentally in a patient with type 1 neurofibromatosis.

CT colonography: implementation, indications, and technical performance - a follow-up national survey

BACKGROUND

Computed tomography colonography (CTC) is an accepted complement or alternative to optical colonoscopy (OC) but its implementation is incompletely analyzed, and technical performance varies between centers.

PURPOSE

To evaluate implementation, indications, and technical performance of CTC in Sweden and to evaluate compliance to international guidelines.

MATERIAL AND METHODS

A structured, self-assessed questionnaire regarding implementation and technical performance of CTC was sent to all eligible radiology departments in Sweden. Eighty-six out of 89 departments replied. Comparisons were made with similar national surveys from 2004 and 2009.

RESULTS

The number of centers performing CTC gradually increased from 23 in 2004 to 77 in 2016. In parallel, centers performing barium enema (BE) examinations have decreased from 89 in 2004 to 13 in 2016. Main reasons stated for still performing BE were lack of resources regarding CTC/OC. Main reasons for not performing CTC were lack of suitable software, lack of machine/reading time, and lack of experience. The majority of centers follow international CTC guidelines. An important exception is fecal tagging, which was implemented in only 63% of the centers. Incomplete OC remains a major indication for CTC, while preoperative CTC in colorectal cancer and follow-up after diverticulitis have emerged as new indications.

CONCLUSION

CTC today is well implemented in routine healthcare but still lacking in capacity. Indications have expanded over time, and most departments perform "state of the art" CTC, although fecal tagging is incompletely implemented.

Lower Gastrointestinal Tract Applications of PET/Computed Tomography and PET/MR Imaging

This article discusses the role of PET/CT and PET/MR imaging in the evaluation of inflammatory and malignant disorders of the lower gastrointestinal tract. This includes a review of the current literature and a discussion of new and emerging research.

A systematic review of gallstone sigmoid ileus management

INTRODUCTION

Gallstone sigmoid ileus is a rare although serious complication of cholelithiasis resulting in large bowel obstruction. The condition accounts for 4% of all gallstone ileus patients. There are no recognized management guidelines currently. Management strategies range from minimally invasive endoscopy and lithotripsy to substantial surgery. We aim to identify trends when managing patients with gallstone sigmoid ileus to help improve outcomes.

METHODS

Literature searches of EMBASE, Medline and by hand were conducted. All English language papers published from 2000 to 2017(Oct) were included. The terms 'gallstone', 'sigmoid', 'colon', 'ileus', 'coleus' and 'large bowel obstruction' were used.

RESULTS

38 papers included, male:female ratio was 8:30. Average age was 81.11 (SD ± 7.59). Average length of preceding symptoms was 5.31days (+/-SD3.16). 20/38 (59%) had diverticulosis. 89% of patients had significant comorbidities documented. 34/38 patients underwent computerized tomography. 31 stones were located within sigmoid colon, 4 at rectosigmoid junction and 2 within descending colon. Average impacted gallstone size was 4.14 cm (2.3-7 cm range). 23/38 (61%) patients' initial management was conservative or with endoscopy ± lithotripsy. Conservative management successfully treated 26% of patients. 28/38 (74%) patients ultimately underwent surgical intervention. 5/38 patients died post-operatively. Patients treated non-operatively had shorter hospital stays (4:12.3days) although not significant (p-value = 0.0056).

CONCLUSIONS

There is no management consensus from the literature. Current evidence highlights endoscopy and lithotripsy as practical firstline strategies. However, surgical intervention should not be delayed if non-operative measures fail or in emergency. Given the complexity of such patients, less invasive timesaving surgery appears practical, avoiding bowel resection and associated complications.

[Mucosal Schwann cells hamartoma: Review of a recently described entity]

Neural lesions of the colon may be masses (schwannomas and neurofibromas) or, more frequently, small polyps including perineuromas, ganglioneuromas and granular cell tumors. Some neural lesions are associated with congenital syndromes (neurofibromatosis-1, multiple endocrine neoplasia-2B). Recently, a new entity has been described named mucosal Schwann cell hamartoma, consisting of an intramucosal neural proliferation; to date, less than forty cases have been reported. We report a further case in a patient from whom a polyp was extirpated during colonoscopy screening. Histologically, the polyp showed a lamina propia that contained spindle-shaped cells of neural aspect which could only be identified after a histochemical and immunohistochemical study.

Quantitative patterns of Hsps in tubular adenoma compared with normal and tumor tissues reveal the value of Hsp10 and Hsp60 in early diagnosis of large bowel cancer

Large bowel carcinogenesis involves accumulation of genetic alterations leading to transformation of normal mucosa into dysplasia and, lastly, adenocarcinoma. It is pertinent to elucidate the molecular changes occurring in the pre-neoplastic lesions to facilitate early diagnosis and treatment. Heat shock proteins (Hsps), many of which are molecular chaperones, are implicated in carcinogenesis, and their variations with tumor progression encourage their study as biomarkers. There are many reports on Hsps and cancer but none to our knowledge on their systematic quantification in pre-neoplastic lesions of the large bowel. We performed immunohistochemical determinations of Hsp10, Hsp60, Hsp70, and Hsp90 in biopsies of large bowel tubular adenomas with moderate grade of dysplasia and compared to normal mucosa and adenocarcinoma with a moderate grade of differentiation (G2). A significant elevation of Hsp10 and Hsp60 only, i.e., in the absence of elevation of Hsp70 or Hsp90, in both epithelium and lamina propria was found in tubular adenoma by comparison with normal mucosa. In contrast, adenocarcinoma was characterized by the highest levels of Hsp10 and Hsp60 in epithelium and lamina propria, accompanied by the highest levels of Hsp70 only in epithelium and of Hsp90 only in lamina propria, by comparison with normal and tubular adenoma counterparts. Hsp10 and Hsp60 are promising biomarkers for early diagnosis of tubular adenoma and for its differentiation from more advanced malignant lesions. Hsp10 and Hsp60 may be implicated in carcinogenesis from its very early steps and, thus, are potentially convenient targets for therapy.

Transient and Non-Transient Intussusceptions of the Large Bowel in Adults: Two Case Reports

BACKGROUND

Intussusception of the large bowel in adults is a very rare pathological condition. However, it has its clinical importance because intussusception is very often associated with an intraluminal lesion.

CASE REPORT

We report two cases of the large bowel intussusception, ileocolic and colorectal. Both intussusceptions were associated with a malignant tumor. However, the clinical presentation was different. One of the intussusceptions was of non-transient character, while the second one resolved spontaneously before operation. Both patients underwent surgery and malignant tumors were found and removed.

RESULTS

The purpose of the article is to draw attention to intussusception and emphasize that intussusception, either transient or non-transient, should be further examined.

CONCLUSIONS

The intussusception may be the first and the only signal of the existence of a malignant tumor, very often colorectal carcinoma.

Giant Filiform Polyposis not Associated with Inflammatory Bowel Disease: A Case Report

Background

Filiform polyposis (FP) is an uncommon cause of non-neoplastic and non-syndromic polyposis. Several hypotheses concerning its pathogenesis have been published. FP is most frequently associated with a post-inflammatory reparative process; indeed, the most frequent association is with inflammatory bowel disease (IBD). FP is characterized by one to hundreds of uniform, slender, arborizing, vermiform projections of the large bowel mucosa and submucosa lined by normal or inflamed colonic mucosa. The most common sites for these polyps are the transverse and descending colon.

Case Report

In this report we present a case of giant FP associated with locally invasive adenocarcinoma of the right colon in a 73-year-old man with no past medical history of IBD.

Conclusion

Few of these cases have been reported in the literature, and out of the approximately 20 of such case reports only one other was associated with colorectal adenocarcinoma.

Small bowel and colon perforation

For patients with small bowel and colonic perforations, a definitive diagnosis of the cause of perforation is not necessary before operation. Bowel obstruction and inflammatory bowel disease are the most common causes of nontraumatic intestinal perforations in industrialized countries, whereas infectious causes of intestinal perforations are more common in developing countries. Treatment of small bowel and colonic perforations generally includes intravenous antibiotics and fluid resuscitation, but the specific management of the bowel depends on the underlying cause of the perforation.

Sigmoid endometriosis and a diagnostic dilemma - A case report and literature review

INTRODUCTION

Intestinal endometriosis is often an infrequently considered diagnosis in female of childbearing age by general surgeon. There is a delay in diagnosis because of constellation of symptoms and lack of specific diagnostic modalities. Patients suffer from intestinal endometriosis for many years before they are diagnosed. Often, such patients are labelled with irritable bowel syndrome. Intestinal endometriosis has a diagnostic time delay of 8-11 years due to its non-specific clinical features and multi-system involvement.

PRESENTATION OF CASE

Our patient was a 32 years old Caucasian female who was referred to us with features of intestinal obstruction. Despite repeated clinical assessments and use of different diagnostic modalities the diagnosis was still inconclusive even after 21 days of her first presentation to primary care physician. She had an exploratory laparotomy, sigmoid colectomy, and Hartmann's procedure with a temporary colostomy with us. Histopathology confirmed endometriosis and also showed melanosis coli. She was referred to the gynaecological team for review and follow up.

DISCUSSION

Intestinal endometriosis should be considered as a differential diagnosis in female patients of childbearing age group presenting with non-specific gastrointestinal signs and symptoms. Our patient manifested intestinal endometriosis and melanosis coli on histopathology suggesting symptoms of long duration.

CONCLUSION

Bowel endometriosis is a less considered and often ignored differential diagnosis in acute and chronic abdomen. This condition has considerable effect on patient's health both physically and psychologically.

Computed tomographic findings of trichuriasis

In this report, we present computed tomographic findings of colonic trichuriasis. The patient was a 75-year-old man who complained of abdominal pain, and weight loss. Diagnosis was achieved by colonoscopic biopsy. Abdominal computed tomography showed irregular and nodular thickening of the wall of the cecum and ascending colon. Although these findings are nonspecific, they may be one of the findings of trichuriasis. These findings, confirmed by pathologic analysis of the biopsied tissue and Kato-Katz parasitological stool flotation technique, revealed adult Trichuris. To our knowledge, this is the first report of colonic trichuriasis indicated by computed tomography.

Effect of special Hungarian probiotic kefir on faecal microflora

AIM: To investigate the effect of a four-week consumption of a special Hungarian probiotic agent (Biofir^®) on the faecal microflora in human healthy subjects.

METHODS: The effect of Biofir^® with 10⁶/cm³ initial germs on the faecal microflora was studied in 120 healthy volunteers (71 females, 49 males). The traditional Russian type kefir was used as control. The various germ groups and pH values were determined in wk 2, 4 and 6.

RESULTS: The number of all microbes increased during the 4-week probiotic treatment. The number of microbes increased 4.3-fold in the control group and 6.8-fold in Biofir-treated group. The probiotic kefir caused multiplication of the probiotic flora, meanwhile the undesired bacteria multiplied in the control group. No significant change of pH values of the faeces was found in both groups.

CONCLUSION: The Hungarian probiotic kefir (Biofir^®) is capable of promoting multiplication of probiotic bacterial flora in the large bowel.