Diagnosis and staging of small bowel tumours

Clinical features and prognosis of malignant small bowel tumors: Experience from a university hospital in Chile

BACKGROUND

Small bowel tumors (SBT) are infrequent and represent a small proportion of digestive neoplasms. There is scarce information about SBT in Latin America.

AIM

To describe the epidemiology, clinical characteristics, diagnostic methods, and survival of malignant SBTs.

METHODS

Retrospective observational study of adult patients with histopathological diagnosis of SBT between 2007 and 2021 in a university hospital in Chile.

RESULTS

A total of 104 patients [51.9% men; mean age 57 years] with SBT. Histological type: neuroendocrine tumor (NET) (43.7%, n=38), gastrointestinal stromal tumors (GIST) (21.8%, n=19), lymphoma (17.2%, n=15) and adenocarcinoma (AC) (11.5%, n=10). GIST was more frequent in duodenum (50%; n=12) and NET in the ileum (65.8%; n=25). Metastasis was observed in 17 cases, most commonly from colon and melanoma. Nausea and vomiting were significantly more often observed in AC (p=0.035), as well as gastrointestinal bleeding in GIST (p=0.007). The most common diagnostic tools were CT and CT enteroclysis with an elevated diagnostic yield (86% and 94% respectively). The 5-year survival of GIST, NET, lymphoma and AC were 94.7% (95%CI: 68.1-99.2), 82.2% (95%CI: 57.6-93.3), 40.0% (95%CI: 16.5-82.8) and 25.9% (95%CI: 4.5-55.7%), respectively. NET (HR 6.1; 95%CI: 2.1-17.2) and GIST (HR 24.4; 95%CI: 3.0-19.8) were independently associated with higher survival compared to AC, adjusted for age and sex.

CONCLUSIONS

Malignant SBT are rare conditions and NETs are the most common histological subtype. Clinical presentation at diagnosis, location or complications may suggest a more probable diagnosis. GIST and NET are associated with better survival compared to other malignant subtypes.

Obscure Bleeding from a Metastatic Small Bowel Tumor Diagnosed Using Motorized Spiral Enteroscopy: A Case Study and a Literature Review

Small bowel tumors are relatively rare, representing only around 5% of all gastrointestinal neoplasms, with a progressively increasing incidence. Currently, there are no established guidelines for diagnostic approaches, screening procedures, or management strategies for small bowel tumors. We present here the case of a patient with a rare type of metastatic tumor of the small bowel originating from primary lung adenocarcinoma who presented with abdominal pain, severe iron-deficiency anemia, and melena. The initial investigations, gastroscopy and colonoscopy, failed to identify the bleeding source. The obscure bleeding source and diagnosis were achieved through power motorized spiral enteroscopy (MSE), which allowed the visualization and biopsy of the tumor. Histopathological examination established the presence of a poorly differentiated non-mucinous adenocarcinoma originating from the lung. This case is reported to provide evidence of the efficiency of MSE in the diagnosis of small bowel tumors, with the method providing higher insertion depth in a reduced amount of time.

Malignant Small Bowel Neoplasms:a review of post-contrast multiphasic multidetector computed tomography

Small bowel neoplasms are rare and account for 3-6% of all gastrointestinal neoplasms. For the diagnosis of small bowel neoplasms, differentiating normal bowel tissue from tumor is critical and depends on imaging modality and scanning techniques. The detection and characterization of small bowel neoplasms have recently improved with the advance of computed tomography (CT) technology. Post-contrast multiphasic CT is an aid to detection and recognition of the vascular nature of small bowel neoplasms. Understanding the typical post-contrast multiphasic CT features of small bowel neoplasms is important because of overlapping features and the necessity of evaluating associated complications and metastases to lymph node and other organs. However, accurate classification of pathologies is still challenging in clinical practice. Texture analysis can quantify complex mathematical patterns within the gray-level distribution of the pixels and voxels of digital images, and texture analysis of the post-contrast multidetector CT data of various tumors has been attracting attention in recent years. The aim of this article is to provide a comprehensive guide to the relevant imaging features for different types of malignant small bowel neoplasms. J. Med. Invest. 69 : 19-24, February, 2022.

CT Texture Analysis for Preoperative Identification of Lymphoma from Other Types of Primary Small Bowel Malignancies

Objectives

To explore the application of computed tomography (CT) texture analysis in differentiating lymphomas from other malignancies of the small bowel.

Methods

Arterial and venous CT images of 87 patients with small bowel malignancies were retrospectively analyzed. The subjective radiological features were evaluated by the two radiologists with a consensus agreement. The region of interest (ROI) was manually delineated along the edge of the lesion on the largest slice, and a total of 402 quantified features were extracted automatically from AK software. The inter- and intrareader reproducibility was evaluated to select highly reproductive features. The univariate analysis and minimum redundancy maximum relevance (mRMR) algorithm were applied to select the feature subsets with high correlation and low redundancy. The multivariate logistic regression analysis based on texture features and radiological features was employed to construct predictive models for identification of small bowel lymphoma. The diagnostic performance of multivariate models was evaluated using receiver operating characteristic (ROC) curve analysis.

Results

The clinical data (age, melena, and abdominal pain) and radiological features (location, shape, margin, dilated lumen, intussusception, enhancement level, adjacent peritoneum, and locoregional lymph node) differed significantly between the nonlymphoma group and lymphoma group (p < 0.05). The areas under the ROC curve of the clinical model, arterial texture model, and venous texture model were 0.93, 0.92, and 0.87, respectively.

Conclusion

The arterial texture model showed a great diagnostic value and fitted performance in preoperatively discriminating lymphoma from nonlymphoma of the small bowel.

Primary Gastro-Intestinal Lymphoma and Gastro-Intestinal Adenocarcinoma: An Initial Study of CT Texture Analysis as Quantitative Biomarkers for Differentiation

BACKGROUND

To explore the potential role of computed tomography (CT) texture analysis and an imaging biomarker in differentiating primary gastro-intestinal lymphoma (PGIL) from gastro-intestinal adenocarcinoma (GIAC).

METHODS

A total of 131 patients with surgical pathologically PGIL and GIAC were enrolled in this study. Histogram parameters of arterial and venous phases extracted from contrast enhanced modified discrete cosine transform (MDCT) images were compared between PGIL and GIAC by Mann-Whitney U tests. The optimal parameters for differentiating these two groups were obtained through receiver operating characteristic (ROC) curves and the area under the curve (AUC) was calculated.

RESULTS

Compared with GIAC, in arterial phase, PGIL had statistically higher 5th, 10th percentiles (p = 0.003 and 0.011) and statistically lower entropy (p = 0.001). In the venous phase, PGIL had statistically lower mean, median, 75th, 90th, 95th percentiles, and entropy (p = 0.036, 0.029, 0.007, 0.001 and 0.001, respectively). For differentiating PGIL from GIAC, V-median + A-5th percentile was an optimal parameter for combined diagnosis (AUC = 0.746, p < 0.0001), and the corresponding sensitivity and specificity were 81.7 and 64.8%, respectively.

CONCLUSION

CT texture analysis could be useful for differential diagnosis of PGIL and GIAC.

Potential MR Enterography Features to Differentiate Primary Small Intestinal Lymphoma From Crohn Disease

OBJECTIVE. The purpose of this study was to assess the MR enterographic features of primary small intestinal lymphoma (PSIL) and compare them with active Crohn disease (CD) presenting with severe (≥ 10 mm) mural thickening of the small bowel. MATERIALS AND METHODS. This retrospective study included 15 patients with pathologically proven PSIL and 15 patients with active inflammatory CD with severe mural thickening. Various morphologic, enhancement, and diffusion parameters were compared between the two groups at MR enterography. The ratios of the upstream to involved luminal diameter and mural thickness to luminal diameter in the involved segment were calculated. An attempt was made to define a predictive model (morphologic score) for discriminating PSIL from CD with severe mural thickening. RESULTS. Patients with PSIL were more likely than those with CD to have unifocal disease (66.7% vs 20.0%, p = 0.025), circumferential involvement (86.7% vs 26.7%, p < 0.001), luminal dilatation (60.0% vs 7.0%, p = 0.005), and an attenuated fold pattern (53.3% vs none, p < 0.001). They were less likely to have serosal surface involvement (40.0% vs 100%, p = 0.001) and mesenteric fat infiltration (33.3% vs 100%, p < 0.001). Median upstream to involved luminal diameter ratio (1.5 vs 9.6, p < 0.001) and mural thickness to involved luminal diameter ratio (1.1 vs 4.3, p = 0.044) were significantly lower in patients with PSIL than in those with CD with severe mural thickening. No significant difference was observed in enhancement and diffusion measures. Morphologic score was based on the presence of luminal dilatation, unifocal involvement, mesenteric fat infiltration, and luminal stricture, yielding accuracy of 98% for differentiation between PSIL and CD with severe mural thickening. CONCLUSION. Morphologic features seen at MR enterography rather than enhancement or diffusion parameters may be valuable for differentiation of PSIL from active CD with severe mural thickening with significantly lower ratios of upstream to involved luminal diameter and mural thickness to involved luminal diameter in PSIL.

Small Bowel Neoplasms: A Pictorial Review

Small bowel tumors are rare and account for approximately 3% of all gastrointestinal tumors in the United States. The incidence of small bowel neoplasms is rising-in particular, there is a rising incidence of small bowel carcinoid tumors. This may in part be due to small bowel lesion identification in an increasing number of cross-sectional imaging studies performed for other indications as well as increased use of advanced imaging techniques to assess specifically for small bowel disease. Diagnosis is a challenge owing to nonspecific clinical manifestation, rare occurrence, and low index of clinical suspicion. Yet, various small bowel neoplasms have characteristic imaging features at CT and MRI when optimal distention of the small bowel is achieved, correlating well with features seen in gross specimens. Understanding the imaging features of small bowel neoplasms is important to improve the radiologist's ability to diagnose and characterize small bowel neoplasms. Most small bowel tumors are clinically silent for long periods, and nearly half of the benign tumors are found incidentally during surgery or at cross-sectional imaging performed for other reasons. The authors review the imaging features of common benign and malignant small bowel neoplasms to aid the radiologist in diagnosis of small bowel tumors. ^©RSNA, 2020.

Magnetic Resonance of Small Bowel Tumors

Tumors of the small intestine represent less than 5% of all gastrointestinal tract neoplasms. Magnetic resonance (MR) imaging is rapidly increasing clinical acceptance to evaluate the small bowel and can be the initial imaging method to investigate small bowel diseases. MR examinations may provide the first opportunity to detect and characterize tumors of the small bowel. Intraluminal and extraluminal MR findings, combined with contrast enhancement and functional information, allow accurate diagnoses and consequently characterization of small bowel neoplasms. This article describes the MR findings of primary small bowel neoplasms and the MR findings for the differential diagnosis are discussed.

Multimodality imaging of small bowel neoplasms

Although the small intestine accounts for over 90% of the surface area of the alimentary tract, tumors of the small intestine represent less than 5% of all gastrointestinal tract neoplasms. Common small bowel tumors typically are well evaluated with cross-sectional imaging modalities such as CT and MR, but accurate identification and differentiation can be challenging. Differentiating normal bowel from abnormal tumor depends on imaging modality and the particular technique. While endoscopic evaluation is typically more sensitive for the detection of intraluminal tumors that can be reached, CT and MR, as well as select nuclear medicine studies, remain superior for evaluating extraluminal neoplasms. Understanding the imaging characteristics of typical benign and malignant small bowel tumors is critical, because of overlapping features and associated secondary complications.

Detecting a rare composite small bowel lymphoma by Magnetic Resonance Imaging coincidentally: A case report with radiological, surgical and histopathological features

INTRODUCTION

Diagnosing lymphoma continues to prove challenging in the clinical practice. Composite lymphoma (CL) is defined by the coexistence of different lymphoma subtypes in the same anatomical location. This condition has seldom been witnessed in the gastrointestinal (GI) tract. We weren't able to find previous cases in the literature about small bowel CL with follicular lymphoma (FL) and classical Hodgkin lymphoma (CHL). Surgery is the treatment of choice to obtain accurate histology, to manage and prevent acute complications. We state that this work has been reported in line with the SCARE criteria.

CASE PRESENTATION

We describe an extremely rare case of small bowel CL, presenting as an intestinal bulky mass with circumferential infiltration of bowel loops. The small bowel tumor was incidentally detected by abdominal Magnetic Resonance Imaging (MRI) in a 64-year-old man who suffered from rectal discomfort and non-specific clinical symptoms. After this radiological finding, the patient underwent multiphase contrast computed tomography (MDCT) for initial staging and to study vascular involvement. Surgery was recommended to obtain an accurate diagnosis both due to initial symptoms of the intestinal obstruction and to avoid small bowel complications. The histopathological examination revealed a small bowel CL composed mainly of B cells FL with also CHL components.

CONCLUSION

It is important to note that involvement of the proximal ileal loops is very rare in small bowel lymphoma. MRI represents a precious diagnostic tool to evaluate the intra and extramural extent of the tumor.

Mass-forming lesions of the duodenum: A pictorial review

Recent advances in imaging have resulted in marked changes in the investigation of the duodenum, which still remains primarily evaluated with videoendoscopy. However, improvements in computed tomography (CT) and magnetic resonance (MR) imaging have made detection and characterization of duodenal mass-forming abnormalities easier. The goal of this pictorial review was to illustrate the most common conditions of the duodenum that present as mass-forming lesions with a specific emphasis on CT and MR imaging. MR imaging used in conjunction with duodenal distension appears as a second line imaging modality for the characterization of duodenal mass-forming lesions. CT remains the first line imaging modality for the detection and characterization of a wide range of duodenal mass-forming lesions.

Small bowel neoplasms: enhancement patterns and differentiation using post-contrast multiphasic multidetector CT

PURPOSE

The purpose of the present study was to analyze the enhancement patterns of small bowel neoplasms on post-contrast multiphasic multidetector CT and to assess the diagnostic capacity for differentiating five tumor types.

METHODS

We performed a retrospective study of data on 92 small bowel neoplasms. The neoplasms were categorized into five groups according to pathology findings, not imaging findings (23 adenocarcinomas; 22 lymphomas; 19 metastases; 18 gastrointestinal stromal tumors [GIST]; 10 neuroendocrine tumors [NET]).

RESULTS

GIST and NET demonstrated a hypervascular pattern in the multiphasic dynamic study. Adenocarcinoma and lymphoma showed a delayed enhancement pattern. Metastasis was classified as an intermediate enhancement pattern. The receiver operating characteristic analyses revealed that attenuation thresholds could be set with acceptable accuracies for most of the small bowel neoplasms.

CONCLUSIONS

Multiphasic dynamic studies may have the potential to improve the diagnostic capacity of multidetector CT for small bowel neoplasms.

Synchronous Ileal Neuroendocrine Tumor and Ovarian Steroid Cell Tumor Present in a Female With Hyperandrogenism

Well-differentiated neuroendocrine tumors (NET) of the ileum are generally slow-growing tumors with metastatic potential that may cause systemic symptoms from the secretion of serotonin, cortisol, and other biologically active substances. Likewise, steroid cell tumors of the ovary are slow-growing tumors that cause systemic symptoms from the functional production of androgens, estrogens, and other hormones. To the best of our knowledge, synchronous ileal NET and ovarian steroid cell tumors have not been previously reported in the English literature. We present a case of a 59-yr-old woman with 2 primary tumors that were found incidentally: a Stage III (T2N1M0) 1.6 cm well-differentiated NET (NET G2) of the terminal ileum with metastasis to a mesenteric lymph node and a 2.4 cm steroid cell tumor of the left ovary. The patient had suffered from hyperandrogenism for several years before diagnosis of an ovarian steroid cell tumor, but had no symptoms attributable to the NET. From review of the literature, this is the first case description of these 2 primaries arising in the same individual.

Role of computed tomography angiography in detection and staging of small bowel carcinoid tumors

Small-bowel carcinoid tumors are the most common form (42%) of gastrointestinal carcinoids, which by themselves comprise 70% of neuroendocrine tumors. Although primary small bowel neoplasms are overall rare (3%-6% of all gastrointestinal neoplasms), carcinoids still represent the second most common (20%-30%) primary small-bowel malignancy after small bowel adenocarcinoma. Their imaging evaluation is often challenging. State-of-the-art high-resolution multiphasic computed tomography together with advanced postprocessing methods provides an excellent tool for their depiction. The manifold interactive parameter choices however require knowledge of when to use which technique. Here, we discuss the imaging appearance and evaluation of duodenal, jejunal and ileal carcinoid tumors, including the imaging features of the primary tumor, locoregional mesenteric nodal metastases, and distant metastatic disease. A protocol for optimal lesion detection is presented, including the use of computed tomography enterography, volume acquisition, computed tomography angiography and three-dimensional mapping. Imaging findings are illustrated with a series of challenging cases which illustrate the spectrum of possible disease in the small bowel and mesentery, the range of possible appearances in the bowel itself on multiphase data and extraluminal findings such as the desmoplastic reaction in mesentery and hypervascular liver metastases. Typical imaging pitfalls and pearls are illustrated.

Aprepitant for the management of refractory emesis in a patient with a small bowel carcinoid tumor

Nausea and vomiting are common distressing symptoms with multiple etiologies. Serotonin and substance P can induce nausea and vomiting by binding to specific receptors (5-hydroxytryptamine3 [5HT3] and neurokinin-1 [NK-1] receptors respectively). Carcinoid tumors, which originate from enterochromaffin cells of the neuroendocrine system, secrete several biologically active amines and peptides, including serotonin and substance P, that are responsible for the distant effects of this tumor. The authors present an 88-year-old lady with metastatic carcinoid tumor, with evidence of carcinoid syndrome. She had nausea and vomiting that became unresponsive to 5HT3 receptor antagonists and other antiemetics. As substance P is released from carcinoid tumors and has a role in the pathogenesis of emesis, the NK-1 receptor antagonist aprepitant was trialed. This provided complete and sustained improvement of the nausea and vomiting until her death 2 months later. This case demonstrates the potential role and rationale of NK-1 receptor antagonists in the management of resistant emesis in patients with carcinoid tumors. Clinical trials are needed to evaluate the efficacy and toxicity of these drugs in the management of emesis in patients with carcinoid syndrome.

Carcinoid tumors of the small-bowel: evaluation with 64-section CT-enteroclysis

PURPOSE

To describe the imaging presentation of carcinoid tumors of the small-bowel at 64-section CT-enteroclysis and determine the sensitivity of this technique for tumor detection.

PATIENTS AND METHODS

The 64-section CT-enteroclysis examinations of 22 patients with histopathologically proven small-bowel carcinoid tumors and those of 6 patients with suspected recurrence after small-bowel resection for carcinoid tumor were reviewed. Images were analyzed with respect to imaging presentation. Sensitivity, specificity, and accuracy, of 64-section CT-enteroclysis for the diagnosis of carcinoid tumor of the small-bowel were estimated with 95% confidence intervals (CIs).

RESULTS

Twenty-five carcinoid tumors were confirmed in 22 patients (prevalence, 22/28; 79%). Overall sensitivity for carcinoid tumor detection was 76% (19/25; 95%CI: 55-91%) on a per-lesion basis. On a per-patient basis, 64-section CT-enteroclysis had a sensitivity of 86% (19/22; 95%CI: 65-97%), a specificity of 100% (6/6; 95%CI: 54-100%) and an accuracy of 89% (25/28; 95%CI: 72-98%) for the diagnosis of carcinoid tumor. Focal small-bowel wall thickening, mesenteric stranding, and mesenteric mass were found in 20/22 (91%), 18/22 (82%) and 15/22 (68%) patients with pathologically confirmed tumors.

CONCLUSION

64-Section CT-enteroclysis shows highly suggestive features for the diagnosis of carcinoid tumor of the small-bowel and achieves high degrees of sensitivity for tumor detection.

[Small bowel tumors: experience at the Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán"]

BACKGROUND

Malignant tumors of the small bowel are uncommon and include multiple histologic strains, which helps explain the existing limited understanding of them. The aim of this study was to evaluate surgically treated small bowel tumors and to determine the clinical and pathological characteristics that can have an impact on patient outcome.

METHODS

A retrospective, observational, and descriptive study was carried out. The case records of patients with small bowel tumor that were surgically treated at the Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán" from 1990 to August 2011 were analyzed using the SPSS version 17.0 statistical package.

RESULTS

Thirty-eight small bowel tumor patients were found that had been operated on within the time frame studied. Fifteen of them were women (39.50%) and 23 were men (60.50%), and the mean age was 55.6 years. The histologic distribution was 13 adenocarcinomas (34.20%), 10 neuroendocrine tumors (26.30%), 8 sarcomas (21.10%) and 4 lymphomas (10.50%). There was an increase in the incidence of sarcomas and adenocarcinomas, whereas lymphomas and neuroendocrine tumors were evenly distributed.

CONCLUSIONS

An increase in small bowel tumor incidence in the last few years was observed and adenocarcinoma was the most frequent tumor in the study population. It is important to have a high degree of suspicion for this disease when patients present with symptoms such as gastrointestinal bleeding, bowel obstruction, anemia, and weight loss, because early diagnosis is essential for guaranteeing favorable outcome.

Small bowel tumors: spectrum of findings on 64-section CT enteroclysis with pathologic correlation

Improvements in helical technology have made detection of benign and malignant small bowel tumors easier so that they are now frequently detected at an early stage. Sixty-four-section CT enteroclysis provides suggestive features that help determine the actual nature of a small bowel tumor in a large number of cases. Specific diagnosis of small bowel tumor is based on a combination of findings that are depicted owing to the use of the multiple capabilities of 64-section CT enteroclysis, allowing optimal planning prior to endoscopic or surgical resection.

Small bowel MRI in adult patients: not just Crohn's disease-a tutorial

Objectives

To provide an overview of less well-known small bowel and mesenteric diseases found at small bowel magnetic resonance (MR) enterography/enteroclysis and to review the imaging findings. MR enterography and enteroclysis are important techniques for evaluation of small bowel diseases. In most centres these techniques are primarily used in Crohn’s disease, and most radiologists are familiar with these MRI findings. However, the knowledge of findings in other diseases is often sparse, including diseases that may cause similar clinical symptoms to those of Crohn’s disease.

Methods

We present a spectrum of less common and less well-known bowel and mesenteric diseases (e.g. internal hernia, intussusception, neuroendocrine tumour) from our small bowel MR database of over 2,000 cases.

Results

These diseases can be found in patients referred for bowel obstruction, abdominal pain or rectal blood loss. Further, in patients with (or suspected to have) Crohn’s disease, some of these diseases (e.g. neuroendocrine tumour, familial Mediterranean fever) may mislead radiologists to erroneously diagnose active Crohn’s disease.

Conclusion

Radiologists should be familiar with diseases affecting the small bowel other than Crohn’s disease, including diseases that may mimic Crohn’s disease.

Malignant tumours of the small intestine: a review of histopathology, multidetector CT and MRI aspects

Small bowel neoplasms, including adenocarcinoma, carcinoid tumour, lymphoma and gastrointestinal stromal tumours, represent a small percentage of gastrointestinal cancers, yet are among those with the poorest prognosis compared with other gastrointestinal malignancies. Unclear clinical scenarios and difficult radiological diagnosis often delay treatment with negative effects on patient survival. Recently, multidetector CT (MDCT) and MRI have been introduced as feasible and accurate diagnostic techniques for the identification and staging of small bowel neoplasms. These techniques are gradually replacing conventional barium radiography as the tool of choice. However, the inherent technical and physiological challenges of small bowel imaging require a familiarity with patient preparation and scan protocols. Adequate knowledge of the histopathology and natural evolution of small bowel neoplasms is also important for differential diagnosis. The aim of this article is to review MDCT and MRI protocols for the evaluation of small bowel tumours and to provide a concise yet comprehensive guide to the most relevant imaging features relative to histopathology.

Imaging of malignant neoplasms of the mesenteric small bowel: new trends and perspectives

This article describes the recent advances in radiological imaging of malignant neoplasms of the mesenteric small bowel and provides an outline of new trends and perspectives that can be anticipated. The introduction of multidetector row technology, which allows the acquisition of submillimeter and isotropic voxels, has dramatically improved the capabilities of computed tomography in the investigation of the mesenteric small bowel. This technology combined with optimal filling of small bowel loops through the use of appropriate enteral contrast agents has markedly changed small bowel imaging. Computed tomography-enteroclysis, which is based on direct infusion of enteral contrast agent into the mesenteric small bowel through a naso-jejunal tube, provides optimal luminal distension. By contrast, computed tomography-enterography is based on oral administration of enteral contrast agent. These two techniques are now well-established ones for the detection and the characterization of small bowel neoplasms. During the same time, combining the advantages of unsurpassed soft tissue contrast and lack of ionizing radiation, magnetic resonance imaging has gained wide acceptance for the evaluation of patients with suspected small bowel neoplasms. Rapid magnetic resonance imaging sequences used in combination with specific enteral contrast agents generate superb images of the mesenteric small bowel so that magnetic resonance-enteroclysis and magnetic resonance-enterography are now considered as effective diagnostic tools for both the detection and the characterization of neoplasms of the mesenteric small bowel. Recent improvements in image post-processing capabilities help obtain realistic three-dimensional representations of tumors and virtual enteroscopic views of the small bowel that are useful for the surgeon and the gastroenteroenteologist to plan surgical or endoscopic interventions. Along with a better knowledge of the potential and limitations of wireless capsule endoscopy and new endoscopic techniques, these recent developments in radiological imaging reasonably suggest that substantial changes in the investigation of small bowel tumors may be anticipated in a near future, thus potentially create a new paradigm shift after standard small bowel follow-through study has been universally abandoned.

Malignant small-bowel neoplasms: spectrum of disease on MR imaging

Malignant neoplasms of the small bowel are among the rarest types of cancer, accounting for only 2% of all gastrointestinal neoplasms. Owing both to the intrinsic difficulty of common radiographic and endoscopic methods in visualising the entire small bowel and the lack of typical physical findings, a delay in diagnosis is common. Recently, magnetic resonance (MR) imaging has become a widely accepted imaging modality in the study of suspected small-bowel neoplasms due to its ability to depict, without exposure to ionising radiation and with excellent soft-tissue contrast, intraluminal disorders in conjunction with mural, extraparietal and regional abnormalities. The aim of this pictorial review is to illustrate the MR appearance of malignant small-bowel neoplasms.

Small intestinal lipomas: Diagnostic value of multi-slice CT enterography

AIM: To analyze the clinical and imaging features of the small intestinal lipomas and to evaluate the diagnostic value of multi-slice computed tomography (CT) enterography.

METHODS: Fourteen cases (one had two intestinal lesions) of surgically confirmed lipomas of the small intestine were retrospectively analyzed. The location, size, clinical and radiological aspects were discussed.

RESULTS: Twelve patients presented with abdominal pain, of whom three complained of paroxysmal colic. Melena or bloody stools was mentioned in five cases. One lesion was detected incidentally during routine physical examination. One lesion was found unexpectedly during the preoperational evaluation for cholecystitis. Examination of the abdomen revealed palpable masses in four cases. Precontrast CT scan showed round or oval well-defined hypo-intense intraluminal masses with the attenuation ranging from -130 HU to -60 HU. On contrast enhancement CT scan, no striking enhancement was seen.

CONCLUSION: The small intestinal lipomas are rare and difficult to diagnose merely based on clinical manifestations, while the characteristic features at small intestinal CT enterography can help establish reliable prospective diagnoses.

Surgically treated primary malignant tumor of small bowel: A clinical analysis

AIM: To evaluate the clinical presentation, treatment and survival of patients with primary malignant tumor of small bowel (PMTSB).

METHODS: Clinicopathologic data about 141 surgically treated PMTSB patients (91 males and 50 females) at the median age of 53.5 years (range 23-79 years) were retrospectively analyzed.

RESULTS: The most common initial clinical features of the patients were intermittent abdominal discomfort or vague abdominal pain (67.4%), abdominal mass (31.2%), bowel obstruction (24.1%), hemotochezia (21.3%), jaundice (16.3%), fever (14.2%), coexistence of bowel perforation and peritonitis (5.7%), coexistence of gastrointestinal bleeding and shock (5.0%), and intraabdominal bleeding (1.4%). Ileum was the most common site of tumor (44.7%), followed by jejunum (30.5%) and duodenum (24.8%). PMTSB had a nonspecific clinical presentation. Segmental bowel resection (n = 81) was the most common surgical procedure, followed by right hemi-colectomy (n = 15), pancreaticoduodenectomy (n = 10), and others (n = 19). Twenty-seven adenocarcinoma patients and 13 malignant lymphoma patients received adjuvant chemotherapy with 5-fluorouracil and cyclophosphamide, adriamycin, vincristine and prednisone, respectively. Information about 120 patients was obtained during the follow-up. The median survival time of PMTSB patients was 20.3 mo. The 1-, 3- and 5-year survival rate was 75.0% (90/120), 40.0% (48/120) and 20.8% (25/120), respectively. Adenocarcinoma was found in 73.7% (42/57), 21.1% (12/57) and 15.8% (9/57) of the patients, respectively. Gastrointestinal stromal tumor was observed in 80.0% (20/25), 72.0% (18/25) and 36.0% (9/25) of the patients, respectively. Carcinoid was detected in 100.0% (15/15), 80.0% (12/15) and 46.7% (7/15) of the patients, respectively. Malignant lymphoma was demonstrated in 69.2% (9/13), 30.8% (4/13) and 0% (0/13) of the patients, respectively.

CONCLUSION: En bloc resection is the principal therapy for most PMTSB and chemotherapy is the important treatment modality for malignant lymphoma and other malignant tumors of small bowel which cannot be radically removed.

Evaluation of small bowel tumors: MR enteroclysis

Magnetic resonance imaging (MRI) of the small bowel has become widely accepted at centers dedicated to the diagnosis and treatment of inflammatory bowel disease, due to the method's diagnostic efficacy. MR enteroclysis is an imaging modality that combines the advantages of enteroclysis and multiplanar MR and allows the detection and the manifestations of small bowel diseases wherever they are located (intraluminal, intramural, or extramural). Magnetic resonance enteroclysis (MRE) is an emerging technique used for the detection and evaluation of small bowel neoplasms. This article illustrates the imaging appearances of small bowel tumors on MRI and the usefulness of MR enteroclysis in the diagnosis and categorization of these tumors, also discussing the role of MRE in comparison with other diagnostic modalities.