Evaluation of submucosal lesions of the large intestine: part 2. Nonneoplastic causes

The spectrum of pneumatosis intestinalis in the adult. A surgical dilemma

Pneumatosis intestinalis (PI) is a striking radiological diagnosis. Formerly a rare diagnostic finding, it is becoming more frequently diagnosed due to the wider availability and improvement of computed tomography scan imaging. Once associated only with poor outcome, its clinical and prognostic significance nowadays has to be cross-referenced to the nature of the underlying condition. Multiple mechanisms of pathogenesis have been debated and multiple causes have been detected during the years. All this contributes to creating a broad range of clinical and radiological presentations. The management of patients presenting PI is related to the determining cause if it is identified. Otherwise, in particular if an association with portal venous gas and/or pneumoperitoneum is present, the eventual decision between surgery and non-operative management is challenging, even for stable patients, since this clinical condition is traditionally associated to intestinal ischemia and consequently to pending clinical collapse if not treated. Considering the wide variety of origin and outcomes, PI still remains for surgeons a demanding clinical entity. The manuscript is an updated narrative review and gives some suggestions that may help make the decisional process easier, identifying patients who can benefit from surgical intervention and those who can benefit from non-operative management avoiding unnecessary procedures.

Lymphangioma of Colon Presenting as an Intramural Tumor

Lymphangiomas are rare and benign vascular malformations of the lymphatic system. They may arise in any location and at all ages and have variable presentation. These lesions in the intestinal wall are reported very rarely. In the case of colonic lymphangiomas, it is more common in late adulthood and old age, which, in this age group is thought to be associated with local disturbances of lymphatic circulation secondary to inflammation, degeneration, surgical procedure, trauma or radiation. The clinical presentation of colonic lymphangiomas varies from incidental findings on imaging to presenting with acute abdomen. The imaging features are usually multilocular cyst in intramural colon and submucosal mass on endoscopy. However, in the case of symptomatic lesions with atypical image findings, and the fact that the disease is rare, preoperative diagnosis is often difficult. On the other hand, although these cystic tumors do not transform into malignancy, they can be locally invasive or complicated, and often require resection. We report a 53-year-old male who had a cystic lymphangioma of the transverse colon illustrated by imaging modalities and recognized via postoperative histopathological examination.

Enterolith at the ileocecal valve mimicking a subepithelial mass

A 32-year-old woman presented with chronic constipation for three years. Colonoscopy revealed a 2.5 cm subepithelial tumor-like lesion at the ileocecal (IC) valve with protrusion of the lesion into the lumen. A CT scan of the abdomen showed an oval-shape laminated calcified lesion adhered to the IC valve and several gallstones. An exploratory laparotomy to enterotomy with stone extraction and open cholecystectomy was performed. Operative findings showed stone erosion into the ileal wall with the lesion being covered with colonic mucosa. Pathologic examination of stones from the intestinal wall revealed an enterolith. The case exemplifies the infrequent cause of a subepithelial lesion of the gastrointestinal tract and a rare presentation of an enterolith as a subepithelial lesion within the terminal ileal wall.

CT Colonography: Improving Interpretive Skill by Avoiding Pitfalls

An earlier incorrect version of this article appeared online. This article was corrected on December 20, 2019.

Ultrasound-guided fine-needle aspiration of a rectal submucosal nodule

Although endoscopic biopsy of a rectal submucosal nodule may be nondiagnostic, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) can be an important tool to make diagnosis. We report a case of a female patient who had an EUS-FNA of a submucosal nodule after a nondiagnostic rectal biopsy. The original diagnosis was erroneously rendered as concerning for necrotic neoplasm. The correct diagnosis of Solesta-induced foreign body reaction was made on reviewing the slides once the history of remote Solesta injection was made available. This case illustrates the pathognomonic features of Solesta-induced rectal nodule and underscores the importance of detailed history as well as inclusion of iatrogenic diseases in the differential to prevent erroneous diagnosis and management. Potential pitfalls in cytopathological diagnosis are discussed.

Anorectal pitfalls in computed tomography colonography

There is a wide array of pathological lesions seen in the anorectal region with CT colonography (CTC), much of which is unique to this location. Many relatively common findings in the anorectal region are typically benign, but can be misinterpreted as malignant. There are also technique-related pitfalls that can impede accurate diagnosis of anorectal findings at CTC. Understanding common and uncommon lesions in the anorectal region as well as recognizing technical pitfalls will optimize interpretation of CTC and decrease the number of missed cancers and false positives. This review will systematically cover that they key pitfalls confronting the radiologist at CTC interpretation of the anorectal region, primarily dividing them into those related to underlying anatomy and those related to technique. Tips for how to effectively handle these potential pitfalls will also be discussed.

Submucosal Fecalith Presenting as a Submucosal Cecal Mass

A wide variety of benign and malignant submucosal lesions may arise from the wall of the large intestine. They can originate in the submucosa or in the muscular propia; furthermore, they can be caused by compression of extrinsic structures.^1,2 We report a case of a submucosal mass identified as a fecalith protruding into the cecum.

Laparoscopic surgery assisted by colonoscopy for a submucosal cecal fecalith presenting as acute appendicitis: A case report

RATIONALE

A cecal submucosal fecalith is extremely rare and is likely to be misdiagnosed as appendicitis with an incarcerated fecalith.

PATIENT CONCERNS

This review presents the case of a female patient complaining of recurrent abdominal pain in the right lower quadrant, similar to the clinical symptoms of appendicitis. Physical examination revealed an abdominal tenderness in the right lower quadrant without rebound tenderness or muscular tension. An ultrasound examination found a mass located in the right lower abdomen. Computed tomography showed a high-density shadow in the cecal cavity.

DIAGNOSES

A fecalith was detected in the submucosal cecal wall. The postoperative pathologic examination showed that the fecalith was located in the submucosa.

INTERVENTIONS

A partial cecal excision was performed under laparoscopic surgery assisted by colonoscopy.

OUTCOMES

The patient was discharged 1 week after surgery without postoperative complications.

LESSONS

Fecaliths should be considered in the differential diagnosis of submucosal occupying lesions of the cecum.

CT colonography with computer-aided detection: recognizing the causes of false-positive reader results

Computed tomography (CT) colonography is a screening modality used to detect colonic polyps before they progress to colorectal cancer. Computer-aided detection (CAD) is designed to decrease errors of detection by finding and displaying polyp candidates for evaluation by the reader. CT colonography CAD false-positive results are common and have numerous causes. The relative frequency of CAD false-positive results and their effect on reader performance on the basis of a 19-reader, 100-case trial shows that the vast majority of CAD false-positive results were dismissed by readers. Many CAD false-positive results are easily disregarded, including those that result from coarse mucosa, reconstruction, peristalsis, motion, streak artifacts, diverticulum, rectal tubes, and lipomas. CAD false-positive results caused by haustral folds, extracolonic candidates, diminutive lesions (<6 mm), anal papillae, internal hemorrhoids, varices, extrinsic compression, and flexural pseudotumors are almost always recognized and disregarded. The ileocecal valve and tagged stool are common sources of CAD false-positive results associated with reader false-positive results. Nondismissable CAD soft-tissue polyp candidates larger than 6 mm are another common cause of reader false-positive results that may lead to further evaluation with follow-up CT colonography or optical colonoscopy. Strategies for correctly evaluating CAD polyp candidates are important to avoid pitfalls from common sources of CAD false-positive results.

Bleeding caecal mass: a rare finding

Bleeding from a caecal mass is a common clinical scenario encountered in surgical practice. Tumours, diverticulitis, inflammation and vascular malformations are the most common causes of this bleeding. We present a case of a submucosal bleeding caecal mass, which turned out to be an appendiceal faecolith protruding into the caecum. Although we found one reported case of this previously, it was not encountered in the emergency setting.

Schwannoma-A Rare Subepithelial Lesion of the Colon

Schwannoma is a benign tumor arising from Schwann cells that form the neural sheath. Primary schwannoma of the colon is rare and a few cases have been reported. We report a case of schwannoma of the colon and present the differential diagnosis that must be considered in the evaluation of colonic subepithelial lesions.

Laparoscopic segmental colectomy for colonic lymphangiomas: A definitive, minimally invasive surgical option

Colonic lymphangioma is an unusual benign malformation. We herein describe two cases. A 36-year-old woman was admitted with one year of intermittent abdominal pain; colonoscopy, abdominopelvic computed tomography and endoscopic ultrasonography (EUS) revealed enlarged cystic masses at the ascending colon. In another 40-year-old man, colonoscopy and EUS revealed an asymptomatic lobulated cystic mass with four small sessile polyps at the sigmoid colon. Both patients underwent laparoscopic segmental colectomy. Both masses were histologically confirmed as cystic lymphangiomas, and the patients were discharged without complications. The management of colonic lymphangioma depends on the individual situation; close surveillance or endoscopic therapy may be appropriate for asymptomatic lesions smaller than 2.5 cm in diameter. Surgical intervention can be considered for larger lesions or in patients who develop complication risks. Laparoscopic segmental colon resection may be recommended to excise relatively large submucosal lesions because it is a definitive, minimally invasive intervention with a fast postoperative recovery.

[Rectal tonsil or lymphoid follicular hyperplasia of the rectum]

The rectal tonsil is a reactive proliferation of lymphoid tissue located in the rectum. The morphology of the lymphoid proliferation of the colon is usually polypoid or, less commonly, nodular. Only in exceptional cases does lymphoid proliferation of the colon present as a mass in the rectum (rectal tonsil), although this is the most common presentation in middle-aged patients. It is important to be familiar with the rectal tonsil because in cases of exuberant growth it can be difficult to distinguish it from other types of masses. We present the case of rectal tonsil in a four-year-old girl. We describe the magnetic resonance imaging findings and review the literature.

CT colonography: pitfalls in interpretation

As with any radiologic imaging test, there are several potential interpretive pitfalls at CT colonography that need to be recognized and handled appropriately. Perhaps the single most important step in learning to avoid most of these diagnostic traps is simply to be aware of their existence. With a little experience, most of these potential pitfalls are easily recognized. This article systematically covers the key pitfalls confronting the radiologist at CT colonography interpretation, primarily dividing them into those related to technique and those related to underlying anatomy. Tips and pointers for how to effectively handle these potential pitfalls are included.

"What is inside this right lower quadrant sac?" Spectrum of computed tomography abnormalities that affect the cecum

The current pictorial is a comprehensive review of the various cecal pathologies, including both those that solely involve the cecum and those in which the cecum may be secondarily involved. The various cecal abnormalities will be categorized as inflammatory, infectious, vascular, neoplastic, congenital, and foreign bodies. Emphasis will be placed on the imaging features that, when coupled with the clinical history, help to reach a diagnosis or to narrow the differential diagnosis.

Intestinal pneumatosis in which CT colonography was of significant diagnostic value: case report

Intestinal pneumatosis refers to the presence of gas in the gastrointestinal wall. It is often difficult to clinically differentiate this condition from gastrointestinal perforation, sometimes resulting in emergency surgery. Imaging studies are important to establish the differential diagnosis. However, there have been few studies showing the efficacy of computed tomography (CT) colonography in diagnosing pneumatosis. We report a case of intestinal pneumatosis in which CT colonography was of significant diagnostic value. A 43-year-old man was referred to our hospital for a detailed investigation of multiple submucosal tumor-like lesions associated with multiple pneumatosis from the cecum to the ascending colon. These lesions were revealed by colonoscopy performed in another hospital on May 21, 2008. Abdominal 3-dimensional CT showed multiple pneumatic lesions from the cecum to the ascending colon, and the patient was diagnosed as having intestinal pneumatosis. The patient is being followed conservatively because he is asymptomatic.

Role of CT colonography in symptomatic assessment, surveillance and screening

INTRODUCTION

When 'whole colonic imaging' is indicated, clinicians must decide between optical colonoscopy, barium enema and CT colonography (CTC). CTC is a relatively new technique which has become increasingly accessible in the UK over the past 5 years. As radiologists have gained experience and scanning parameters have standardised, there have been substantial improvements in both the accuracy and safety of CTC.

METHODS

We review evidence from observational studies and randomised trials, and draw on expert opinion, to provide a comprehensive discussion of the current role of CTC in both symptomatic and asymptomatic individuals.

CONCLUSIONS

The emergence of CTC could soon entirely obviate the need for barium enema. CTC now has a complementary role alongside colonoscopy in symptomatic patients and a possible future role in colorectal cancer screening in the UK.

MRI findings of rectal submucosal tumors

Rectal submucosal lesions encompass a wide variety of benign and malignant tumors involving the rectum. With optical colonoscopy, any mass-like protrusion covered by normal mucosa, whether the underlying process is intramural or extramural in origin, may be reported as a submucosal lesion. Whereas the assessment of submucosal lesions may be limited with performing optical colonoscopy, cross-sectional imaging such as CT, transrectal ultrasonography and MRI allows the evaluation of perirectal tissues and pelvic organs in addition to the entire thickness of the rectum, and so this is advantageous for the assessment of rectal submucosal tumors. Among these, MRI is the best investigative modality for soft tissue characterization. Therefore, knowledge of the MRI features of rectal submucosal tumors can help achieve accurate preoperative diagnoses and facilitate the appropriate management.

Evaluation of MR diffusion-weighted imaging in differentiating endometriosis infiltrating the bowel from colorectal carcinoma

OBJECTIVE

Endometriosis infiltrating the bowel may be difficult to differentiate from colorectal carcinoma in cases that present with non-specific clinical and imaging features. The aim of this study is to assess the value of MR diffusion-weighted imaging (DWI) in differentiating endometriosis infiltrating the bowel from colorectal carcinoma.

METHODS

In 66 patients, MR DWI was added to the standard imaging protocol in patients visiting our outdoor MR clinic for the analysis of suspected or known deep infiltrating endometriosis (DIE). In patients diagnosed with DIE infiltrating the bowel on MR imaging, high b-value diffusion-weighted images were qualitatively assessed by two readers in consensus and compared to high b-value diffusion weighted images in 15 patients evaluated for colorectal carcinoma. In addition, ADC values of lesions were calculated, using b-values of 50, 400 and 800 s/mm(2).

RESULTS

A total of 15 patients were diagnosed with DIE infiltrating the bowel on MR imaging. Endometriosis infiltrating the bowel showed low signal intensity on high b-value diffusion-weighted images in all patients, whereas colorectal carcinoma showed high signal intensity on high b-value diffusion-weighted images in all patients. Mean ADC value in endometriosis infiltrating the bowel (0.80 ± 0.06 × 10(-3)mm(2)/s) was significantly lower compared to mean ADC value in colorectal carcinoma (0.86 ± 0.06 × 10(-3 )mm(2)/s), but with considerable overlap between ADC values.

CONCLUSION

Only qualitative assessment of MR DWI may be valuable to facilitate differentiation between endometriosis infiltrating the bowel and colorectal carcinoma.

Acute small bowel obstruction secondary to intestinal endometriosis, an elusive condition: a case report

Background

Endometriosis is a benign condition affecting females of reproductive age. Although intestinal endometriosis is common it is rare for the condition to manifest as an acute bowel obstruction secondary to ileocaecal and appendicular endometriosis. This case is important to report as it highlights the diagnostic difficulty this particular condition presents to an emergency surgeon.

Case presentation

We present the case of a 33 year old female of Asian origin who presented with symptoms and signs of an acute small bowel obstruction. A right hemicolectomy for suspected malignancy was performed with an ileocolic anastomosis. Histological examination demonstrated extensive endometriosis of the appendix and ileocaecal junction.

Conclusion

Enteric endometriosis should be considered as a differential diagnosis when assessing females of reproductive age with acute small bowel obstruction. A high index of suspicion is required to arrive at a diagnosis of this elusive condition.

Cadherin expression in gastrointestinal tract endometriosis: possible role in deep tissue invasion and development of malignancy

Cadherins are cell surface proteins crucial for cell adhesion and tissue integrity. The mechanism of deep tissue invasion in gastrointestinal endometriosis is unknown and may be related to the altered expression of these cell surface proteins. The goal of this study was to evaluate the expression of N-cadherin, E-cadherin, and beta-catenin in peritoneal endometriotic implants, gastrointestinal endometriosis, and carcinoma arising in gastrointestinal endometriosis. Cases of peritoneal endometriosis, gastrointestinal endometriosis, and carcinoma arising in gastrointestinal endometriosis were identified from our pathology database. Immunohistochemistry was performed using antibodies against N-cadherin, E-cadherin, and beta-catenin on representative tissue sections. Cases of normal proliferative and secretory endometrium and adenomyosis were included in the study for comparison. The intensity and extent of staining for each marker was scored semiquantitatively. Appropriate positive and negative controls were used. A total of 38 cases (peritoneal endometriosis (n=14), gastrointestinal endometriosis (n=21: 11 colon, 8 appendix, 2 small bowel), and 3 cases of endometrioid carcinoma arising in colonic endometriosis (n=3)) were included in the study. Compared with normal proliferative endometrium, N-cadherin expression was decreased in intensity and extent in secretory endometrium. Peritoneal and gastrointestinal endometriosis also showed markedly decreased expression of N-cadherin compared with proliferative endometrium. All three cases of carcinoma arising in colonic endometriosis showed a total loss of N-cadherin in the tumor, but preserved E-cadherin and beta-catenin expression. In these cases, areas of benign endometriotic glands near the tumor showed weak and focal N-cadherin expression that was gradually lost. Moderate-to-strong membranous staining for beta-catenin expression and variable intensity of E-cadherin expression was seen diffusely in normal endometrium and all study cases. These results strongly suggest that alterations of N-cadherin expression in gastrointestinal endometriosis may have an important role in the mechanism that underlies deep tissue invasion, and possibly also in the development of malignancy.

Noninvasive radiologic imaging of the large intestine: a valuable complement to optical colonoscopy

PURPOSE OF REVIEW

Radiologic imaging of the large intestine continues to evolve and expand the potential for noninvasive diagnosis. The aim of this review is to provide an update on current and emerging clinical capabilities for a variety of radiologic diagnostic imaging tools for evaluating the colon and rectum.

RECENT FINDINGS

The utility of computed tomography for the evaluation of symptomatic inflammatory and neoplastic conditions of the colon is well established, but the clinical role of computed tomography colonography is rapidly evolving. In addition to a number of diagnostic indications, computed tomography colonography is emerging as a potential frontline colorectal screening test for cancer prevention. MRI has become increasingly valuable for rectal cancer staging and inflammatory bowel disease but has yet to gain momentum for polyp evaluation. PET imaging has been primarily utilized for oncologic indications, but also holds considerable potential for inflammatory conditions. Other imaging modalities, such as the barium enema, conventional radiography, and ultrasound, play a much more limited role.

SUMMARY

Advances in radiologic imaging of the colorectum will continue to expand the capabilities and clinical indications for noninvasive diagnosis, allowing for a greater emphasis on the complementary roles of tissue sampling and therapy with optical colonoscopy.

[Diseases of the peritoneum and mesenterium]

Peritoneal diseases can be seen in the different imaging modalities either as fluid collections or solid tumors along the ligaments, mesenteries, and spaces of the peritoneal cavity. The broad spectrum of different abnormalities includes inflammatory, infectious, traumatic, and neoplastic diseases. In this article, a large variety of peritoneal abnormalities such as ascites, peritonitis, intraperitoneal hemorrhage, and both primary and secondary peritoneal tumors are discussed. The different imaging modalities, characteristic radiological features, and typical pathways of anatomic spread are explained.