Diagnosis and categorization of small bowel neoplasms: role of computed tomography

A Stromal Tumor Presenting as a Pseudoaneurysmal Dilation of the Small Bowel Mimicking a Lymphoma on FDG PET/CT

ABSTRACT

An 84-year-old woman visited our hospital with hematochezia for 1 month. Abdominal CT and FDG PET/CT showed local thickening of the small intestine, resembling an intestinal aneurysmal dilatation. Thus, a lymphoma was suspected, and surgical resection was performed. The final pathology revealed an exophytic small bowel stromal tumor with perforation, causing pseudoaneurysmal dilation of the small bowel. This case emphasized the importance of considering a small bowel stromal tumor when faced with similar FDG PET/CT findings.

[Small Bowel Tumors and Polyposis: How to Approach and Manage?]

Although small bowel the mainly occupies the most part of the gastrointestinal tract, small intestine tumors are rare, insidious in clinical presentation, and frequently represent a diagnostic and management challenge. Small bowel tumors are generally classified as epithelial, mesenchymal, lymphoproliferative, or metastatic. Familial adenomatous polyposis and Peutz-Jeghers syndrome are the most common inherited intestinal polyposis syndromes. Until the advent of capsule endoscopy (CE) and device-assisted enteroscopy (DAE) coupled with the advances in radiology, physicians had limited diagnostic examination for small bowel examination. CE and new radiologic imaging techniques have made it easier to detect small bowel tumors. DAE allows more diagnosis and deeper reach in small intestine. CT enteroclysis/CT enterography (CTE) provides information about adjacent organs as well as pictures of the intestinal lumen side. Compared to CTE, Magnetic resonance enteroclysis/enterography provides the advantage of soft tissue contrast and multiplane imaging without radiation exposure. Treatment and prognosis are tailored to each histological subtype of tumors.

Patient with Lynch syndrome with subsequent development of small bowel adenocarcinoma

Small bowel adenocarcinoma (SBA) is a rare cancer in the general population, but the incidence increases in patients with Lynch syndrome. The present case describes a 57-year-old white woman with a history of colon cancer status posthemicolectomy and diagnosis of Lynch syndrome. Twenty years after her operation, the patient presented with vague abdominal discomfort and constipation, and underwent an exploratory laparotomy which revealed a stage 3A SBA. Genetic testing of the specimen provided evidence of microsatellite instability and faulty DNA repair supporting aetiology of Lynch syndrome. This case is unique in that SBA, if present in patients with Lynch syndrome, is usually a presenting symptom and has not been widely described in literature as an occurrence so many years after. As a result, this case highlights the importance of a low threshold for a thorough evaluation in patients with Lynch syndrome who present with signs of small bowel obstruction.

The elusive small bowel adenocarcinoma in the terminal ileum-A case report

INTRODUCTION

Small bowel malignancies are rare and often present with non-specific symptoms. Because of this, diagnosis of small bowel malignancies is often missed.

PRESENTATION OF CASE

71-year-old male presented with a four-week history of right iliac fossa pain and loss of weight. Laboratory tests showed a raised C-reactive protein, but all other pathology results and tumour-associated antigens were normal. Computed tomography (CT) of the abdomen demonstrated an inflammatory mass extending laterally into the pelvic wall. The patient underwent an elective laparotomy and resection of the small bowel tumour. Intra-operative findings included a small bowel tumour adherent to two loops of small bowel. Histology demonstrated a 50 mm poorly differentiated mucinous adenocarcinoma of the terminal ileum.

DISCUSSION

Clinical presentation of small bowel adenocarcinoma is often non-specific, which leads to a delay in diagnosis. As a result, disease is often advanced by the time of diagnosis. Upper and lower endoscopy is useful in detecting tumours in the duodenum and terminal ileum. Video capsule endoscopy allows visualisation of the entire small bowel mucosa. Enteroscopy can also be used to obtain biopsies and perform therapeutic interventions. CT is able to detect abnormalities in 80% of patients, while CT and MR (magnetic resonance) enteroclysis give better visualisation of the mucosa and mural thickness. Surgical exploration may be indicated in patients with a strong clinical suspicion.

CONCLUSION

In conclusion, small bowel malignancies are rare and clinicians are reminded to have a high index of suspicion for small bowel malignancies in patients who present with non-specific abdominal symptoms.

Primary Jejunal Adenocarcinoma Presenting as Bilateral Ovarian Metastasis

Small intestinal tumors are rare with adenocarcinoma of the small intestine accounting for less than 2% of all gastrointestinal cancers. Primary jejunal adenocarcinoma constitutes a minute portion of small intestine adenocarcinomas. Clinically, this cancer presents at latter stages of its progression, mainly due to vague and non-specific symptoms, and the difficulty encountered in accessing the jejunum on upper endoscopy. Diagnosis of jejunal adenocarcinoma is usually inconclusive with the use of computed tomography (CT) scan, small bowel series, or upper endoscopy. Laparoscopy followed by frozen section biopsy provides a definitive diagnosis. In the past decade, balloon-assisted enteroscopy (BAE) and capsule endoscopy have become popular as useful modalities for diagnosing small bowel diseases. Wide excisional jejunectomy is the only treatment option with an estimated 5-year survival of 40-65%. Physicians are advised to suspect jejunal adenocarcinoma as a differential diagnosis in patients who present with non-specific symptoms of abdominal pain, nausea, vomiting, weight loss, anemia, gastrointestinal bleeding or signs of small bowel obstruction. We present a rare case of a 37-year-old woman with suspected bilateral ovarian masses, which was immunohistochemically confirmed as primary jejunal adenocarcinoma with bilateral ovarian metastasis.

Management of small bowel polyps: A literature review

Despite the small bowel comprising 90% of the mucosal surface area of the gastrointestinal tract, it is a rare site for neoplasia and only accounts for a little over 3% of the tumors that arise in the digestive tract. Benign small bowel lesions include lipomas, lymphangiomas, leiomyomas, neurofibromas, nodular lymphoid hyperplasia and adenomas, many of which are precursors to malignant lesions. Several polyposis syndromes are associated with small bowel polyps as well, including familial adenomatous polyposis syndrome, lynch syndrome, Peutz-Jeghers syndrome, Cowden syndrome and juvenile polyposis syndrome. Our aim was to review non-malignant small bowel polyps and discuss the prevalence, typical location, clinical presentation, diagnosis, endoscopic and histologic description and lastly management of each of these lesions.

Small Bowel Neoplasms and Polyps

The small intestine is a relatively privileged organ that only rarely develops malignant or even benign tumors. Given this rarity, the relative inaccessibility of the organ during routine endoscopic procedures, and the typical absence or nonspecific nature of clinical manifestations, these tumors often go undiagnosed. Treatment and prognosis are tailored to each histological subtype of tumor. This chapter will discuss the epidemiology, presentation, diagnostics, and management for the most common small bowel tumors, and will highlight the importance of recognizing patients at higher risk of small bowel neoplasia.

Adenocarcinoma of Small Bowel

Small bowel cancer is one of the rarest cancers in the gastrointestinal tract. The diagnosis is usually late and most patients presented with the advanced stage. Because of this rarity, there is limited data when making decisions for treatment and biological behavior. Most forms of the cancer occur in the duodenum with surgery being the treatment of choice if the cancer is operable. Chemotherapy has an accepted role in duodenal cancer, with the best form being regimen, which yields the best result in combination with capecitabin and oxaliplatin. Our case patient was present with liver metastasis and a huge mass in her first duodenal region so we were required to use chemotherapy and radiotherapy. Like other duodenal cancers, the metastasis decreased her survival and she died about 13 months after diagnosis.

Small bowel adenocarcinomas--existing evidence and evolving paradigms

Small bowel cancers account for 3% of all gastrointestinal malignancies and small bowel adenocarcinomas represent a third of all small bowel cancers. Rarity of small bowel adenocarcinomas restricts molecular understanding and presents unique diagnostic and therapeutic challenges. Better cross-sectional imaging techniques and development of enteroscopy and capsule endoscopy have facilitated earlier and more-accurate diagnosis. Surgical resection remains the mainstay of therapy for locoregional disease. In the metastatic setting, fluoropyrimidine and oxaliplatin-based chemotherapy has shown clinical benefit in prospective non-randomized trials. Although frequently grouped under the same therapeutic umbrella as large bowel adenocarcinomas, small bowel adenocarcinomas are distinct clinical and molecular entities. Recent progress in molecular characterization has aided our understanding of the pathogenesis of these tumours and holds potential for prospective development of novel targeted therapies. Multi-institutional collaborative efforts directed towards cogent understanding of tumour biology and designing sensible clinical trials are essential for developing improved therapeutic strategies. In this Review, we endeavour to outline an evidence-based approach to present-day management of small bowel adenocarcinoma, describe contemporary challenges and uncover evolving paradigms in the management of these rare 'orphan' neoplasias.

Jejunal adenocarcinoma: an elusive diagnosis

Tubercular stricture of small bowel is a common cause of subacute intestinal obstruction in India. In a small subset of patients the cause of the intestinal obstruction could be adenocarcinoma of jejunum. It is difficult to diagnose preoperatively. The point of concern is compared to tubercular stricture, the treatment of jejunal adenocarcinoma is always surgical in the form of cancer directed surgery. The operating surgeon needs to have a very high suspicion for jejunal adenocarcinoma because the timely treatment offers the best survival in otherwise an aggressive disease with bleak prognosis.

Small bowel adenocarcinoma: understaged and undertreated?

BACKGROUND

Primary small bowel adenocarcinoma (SBA) is a rare, chemoresistant tumor with an aggressive clinical nature. Surgery is the mainstay of therapy, but the extent of lymph node (LN) recovery necessary for optimal care of jejunoileal SBA is unknown.

MATERIALS AND METHODS

The SEER database was queried to identify patients whose primary jejunoileal SBA was diagnosed between 1995 and 2005. Patients were grouped by AJCC stage and number of LNs recovered from the surgical specimen.

RESULTS

Of 1444 patients with primary SBA, 93 (6.4%), 529 (36.6%), 356 (24.7%), and 466 (32.3%) were initially diagnosed with stage I, II, III, and IV disease, respectively. Five-year overall survival (OS) rate was 59.8%, 39.5%, 27.0%, and 3.2% for patients with stage I, II, III, and IV SBA, respectively. When ≥10 nodes were recovered, OS rate increased nonsignificantly in stage I (73.2% vs. 55.6%) and significantly in stage II (61.8% vs. 32.9%, P < .001) but was unchanged in stage III (27.4% vs. 27.3%, P = .13). Recovery of ≥10 nodes occurred in 26.9%, 23.6%, and 42.1% of patients with stage I, II, and III SBA, respectively. Multivariate analysis identified age, AJCC stage, site of primary tumor, recovery of ≥10 LNs, and number of positive nodes as significant for OS.

CONCLUSIONS

We have found SBA staging is largely inadequate. Our results suggest recovery of ≥10 LNs ensures accurate staging. Improvement in stage II SBA OS after adequate LN may reflect a high degree of understaging in this dataset rather than a therapeutic effect of LAD.

Comprehensive review of small bowel metastasis from head and neck squamous cell carcinoma

Secondary tumours of small intestine account for 10% of all small bowel cancers. The most common sites of primary tumour metastasizing to small bowel are uterus, cervix, colon, lung, breast and melanoma. The majority of these metastatic tumours come from adenocarcinoma primaries; squamous cell carcinoma constitutes a very small proportion of all metastatic small intestinal lesions. Metastasis to small bowel by head and neck squamous cell carcinoma is extremely rare and carries an unfavourable prognosis. Owing to the limited number of published studies, its characteristic features, clinical presentation and outcomes are poorly described. This work aims at specifying these characteristics by reviewing, compiling, analysing and reporting all published cases in the published literature on small bowel metastasis secondary to head and neck squamous cell carcinoma. To the best of our knowledge, this is the first comprehensive review article on the small intestinal metastasis from head and neck squamous cell carcinoma.

Capsule endoscopy: technique and indications

Since it was introduced in 2000, capsule endoscopy has become the gold standard for endoscopic examination of the small bowel in several clinical situations such as obscure gastrointestinal bleeding, suspicion of Crohn's disease, and surveillance of polyposis syndromes. In this technique a miniaturised endoscope, embedded in a swallowable capsule, is propelled through the gut by peristalsis and reaches the right colon in 5-8h. Images captured by the capsule are recorded on a hard drive in a belt worn by the patient. In addition to the extensive literature currently available on small bowel CE, new capsule devices are currently under evaluation for the examination of the colon with the purpose of screening for colorectal cancer, and of the oesophagus for screening for oesophageal varices and Barrett's oesophagus. These latter indications currently remain under evaluation. This review considers the technical aspects of capsule endoscopy and discusses the indications. Issues of safety and tolerance are also discussed.

Multidetector CT in small-bowel neoplasms

PURPOSE

The aim of this study was to assess the diagnostic potential of multidetector computed tomography (MDCT) in the evaluation of small-bowel neoplasms.

MATERIALS AND METHODS

We studied 120 patients with suspected small-bowel disease by 16-slice MDCT after oral administration of a polyethylene glycol solution (n=56) or methylcellulose via a nasojejunal tube (n=64). Unenhanced and contrast-enhanced CT was performed. Contrast-enhanced CT images were acquired 40 s after IV injection of 130 ml of iodinated contrast agent at a rate of 3 ml/s. Multiplanar reconstructions were performed at the end of the examinations.

RESULTS

Fifteen patients were found to be affected by small-bowel neoplasm (six had non-Hodgkin's lymphoma, three had carcinoid tumour, two had Peutz-Jeghers syndrome, two had adenocarcinoma, two had melanoma metastases, one had lipoma). In the remaining patients, 58 cases of Crohn's disease and seven miscellaneous diseases were detected. All findings were confirmed by barium studies, surgery or endoscopy.

CONCLUSIONS

MDCT performed after bowel-loop distension with low-density contrast material and IV administration of iodinated contrast agent is a reliable method for diagnosing and staging small-bowel neoplasms.

Multidetector row CT of small bowel tumours

Computed tomography is being increasingly used for the evaluation of patients with vague abdominal symptoms, and may provide the initial opportunity to detect and characterize tumours of the small bowel. The recognition of imaging features on CT allows distinction to be made between benign and malignant neoplasms. Multidetector row CT (MDCT) provides high-resolution imaging and helps in precise localization and characterization of lesions. This article illustrates the imaging appearances of small bowel tumours on MDCT and demonstrates the usefulness of multiplanar reformatting (MPR) in the diagnosis and categorization of these tumours.

Prognostic Factors of Primary Small Bowel Adenocarcinoma: Univariate and Multivariate Analysis

BACKGROUND

Adenocarcinoma of the small bowel is relatively less common than malignancies of the esophagus, stomach, and colorectum. In small bowel adenocarcinoma, various prognostic factors influence the disease-free status and overall survival rates.

MATERIALS AND METHODS

Eighty patients who were diagnosed with small bowel adenocarcinoma and treated at our institute between 1983 and 2003 were retrospectively reviewed.

RESULTS

The patients included 40 men and 40 women with an age range of 15 to 93 years (median: 62 years). Only 51.3% of patients were accurately proved preoperatively to have a malignancy by endoscopic biopsy. Sixty patients underwent surgical treatment, and 45 of those patients had curative resection. The follow-up period ranged from 2.5 to 229.7 months, with a median of 9.1 months. The cumulative 1-, 3-, and 5-year survival rates for all patients (excluding 3 patients who died in the immediate postoperative period) were 43.6%, 22.8%, and 17.5%, respectively. The cumulative 1-, 3-, and 5-year disease-free survival rate for all 43 patients with curative resection (excluding 2 patients who died in the immediate postoperative period) was 54.9%, 30.5%, and 27.4%, respectively. Meanwhile, multivariate analysis with Cox proportional hazards analysis demonstrated that earlier tumor stages (stages I and II) and curative resection were two independent factors influencing favorable overall survival. Lymph node metastasis was the only independent factor predicting poor disease-free survival in patients undergoing curative resection.

CONCLUSIONS

Poor prognosis of small bowel adenocarcinoma may be related to a delay in the diagnosis and treatment of the disease. Curative resection is the aim of surgical treatment for small bowel adenocarcinoma. Lymph node metastasis at presentation of the disease predicts tumor recurrence and distant metastasis after curative surgical treatment.

Capsule endoscopy in 2005: facts and perspectives

Capsule endoscopy has recently been introduced to explore endoscopically the whole small intestine, fulfilling a gap between examinations of the upper and lower gastrointestinal tract. The technique consists of a miniaturized endoscope, embedded in a swallowable capsule that is propulsed by peristalsis and achieves the journey to the right colon in five to eight hours. Images captured by the capsule are recorded on a hard drive worn in a belt by the patient. The main indication for capsule examination is the examination of the small bowel to find a bleeding lesion in patients with obscure bleeding. Several studies have shown that the diagnostic yield of capsule endoscopy is superior to that of push enteroscopy in this indication. Other possible indications are patients with suspected intestinal location of Crohn's disease, familial adenomatous polyposis, complicated coeliac disease and lesions due NSAIDs. The review contains information on the technical aspects of capsule endoscopy and discusses the indications. Issues of safety and tolerance are also discussed.

CT enteroclysis: technique and clinical applications

CT enteroclysis (CTE) has been gradually evolving with technical developments of spiral and multidetector row CT technology. It has nowadays become a well-defined imaging modality for the evaluation of various small bowel disorders. Volume challenge of 2L of enteral contrast agent administrated to the small bowel via a nasojejunal catheter ensures luminal distension, the prerequisite for the detection of mural abnormalities, also facilitating the accurate visualization of intraluminal lesions. CT acquisition is centered on small bowel loops, reconstructed in thin axial slices and completed by multiplanar views. Image analysis is essentially done in cine-mode on work-stations. CTE is of particular diagnostic value in intermediate or advanced stages of Cohn's disease, including the depiction of extraintestinal complications. It has become the imaging modality of choice for the localization and characterization of small bowel tumors. The cause and degree of low-grade small bowel obstruction is more readily analyzed with the technique of CTE than conventional CT. Limitations of CTE concern the assessment of pure intestinal motility disorders, superficial mucosal lesions and arteriovenous malformations of the small bowel, which are not consistently visualized. CTE should be selectively used to answer specific questions of the small bowel. It essentially contributes to the diagnostic quality of modern small bowel imaging, and therefore deserves an established, well-defined place among the other available techniques.

Small Bowel Adenocarcinoma: A Rare but Aggressive Disease

Unlike the colon and rectum, the small intestine is associated with a very low rate of tumor occurrence. Adenocarcinomas represent the most frequent of these rare digestive tumors and are often fatal as a result of tardy diagnosis. Regardless of the stage, surgery usually remains the cornerstone of small bowel adenocarcinoma therapy. Because of the rarity of the disease, very few significant clinical trials have identified any efficient nonsurgical treatment; however, recent data indicate these tumors might be sensitive to chemotherapy alone or in association with radiation therapy. Conversely, a great deal of progress has been achieved in diagnosis of the tumor, whether by adaptation of existing techniques or development of new ones. We reviewed the clinical aspects of this rare but aggressive disease, focusing on new diagnostic procedures as well as on recent advances in their therapeutic management.

Exploration de l’intestin grêle par les techniques d’imagerie en coupes

Recent advances of cross sectional imaging allow optimal evaluation of the small bowel. This chapter will detail technical considerations and emphasize the role of imaging in the evaluation of the most common diseases of the small bowel.

Multidetector-row computed tomography and 3-dimensional computed tomography imaging of small bowel neoplasms: current concept in diagnosis

The diagnosis of small bowel neoplasms can present a difficult challenge to the radiologist because the tumors are uncommon, often small, and may be difficult to detect radiographically. The most common small bowel neoplasms include adenocarcinoma, carcinoid, lymphoma, and gastrointestinal stromal tumors. The location and computed tomography (CT) appearance of the small bowel tumors may aid in the diagnosis. For instance, small bowel adenocarcinoma occurs more frequently in the duodenum and may result in obstruction. Carcinoid tumors are more common in the ileum and are typically hypervascular submucosal masses that produce a characteristic mesenteric mass when they spread to the mesenteric nodes. Lymphoma can occur anywhere along the gastrointestinal tract and have a variable CT appearance. It may appear as a single mass, multiple masses, an infiltrating lesion resulting in aneurysmal dilatation of the bowel, or as an exophytic mass. Gastrointestinal stromal tumors are more common in the jejunum and ileum and usually appear exophytic and bulky often with ulceration. Traditionally, small bowel series and enteroclysis have been used for imaging patients with suspected small bowel tumors. More recently, CT is beginning to play a more important role for this clinical indication. The thinner collimation possible with multidetector CT (MDCT) along with water as oral contrast and a good intravenous contrast bolus may improve the sensitivity of CT for detecting small bowel tumors. In addition, MDCT scanners improve the quality of the 3-dimensional CT (3D CT) images that are valuable to the clinicians and surgeons for surgical planning. It is important for the radiologist to be familiar with the CT appearance of these neoplasms and the potential role of MDCT and 3D imaging in their diagnosis and surgical planning.

Computed tomography in gastrointestinal stromal tumors

The aim of this study was to define the imaging characteristics of primary and recurrent gastrointestinal stromal tumors (GIST) in computed tomography with respect to the tumor size. Computed tomography was performed in 35 patients with histologically confirmed gastrointestinal stromal tumors and analyzed retrospectively by two experienced and independent radiologist. The following morphologic tumor characteristics of primary ( n=20) and ( n=16) recurrent tumors were evaluated according to tumor size, shape, homogeneity, density compared with liver, contrast enhancement, presence of calcifications, ulcerations, fistula or distant metastases and the anatomical relationship to the intestinal wall, and the infiltration of adjacent visceral organs. Small GIST (<5 cm) showed a sharp tumor margin with homogeneous density and structure on unenhanced and contrast-enhanced images, and were characterized by an intraluminal tumor growth. Intermediate sized GIST (>5-10 cm) demonstrated an irregular shape, inhomogeneous density on unenhanced and contrast-enhanced images, a combined intra- and extraluminal tumor growth with aggressive findings, and infiltration of adjacent organs in 9 primary diagnosed and 2 recurrent tumors. Large GIST (>10 cm), which were observed in 8 primary tumors and 11 recurrent tumors, showed an irregular margin with inhomogeneous density and aggressive findings, and were characterized by signs of malignancy such as distant and peritoneal metastases. Small recurrent tumors had a similar appearance as compared with large primary tumors. Computed tomography gives additional information with respect to the relationship of gastrointestinal stromal tumor to the gastrointestinal wall and surrounding organs, and it detects distant metastasis. Primary and recurrent GIST demonstrate characteristic CT imaging features which are related to tumor size. Aggressive findings and signs of malignancy are found in larger tumors and in recurrent disease. Computed tomography is useful in detection and characterization of primary and recurrent tumors with regard to tumor growth pattern, tumor size, and varied appearances of gastrointestinal stromal tumors, and indirectly gives hints regarding dignity and therefore prognostic outcome.

Tumor and tumor-like lesions of duodenum: CT and barium imaging features

Neoplasms of the duodenum, either primary or secondary, are uncommon. However, imaging diagnosis for presurgical evaluation is extremely important due to complex regional anatomy. Computed tomography (CT) and barium-based double contrast examination (UGI series) are most frequently employed to evaluate the tumor invasion and intraluminal mucosal pattern. In this pictorial review, the CT and UGI series imaging features of benign and malignant duodenal tumors and tumor-like lesions are demonstrated and discussed.

Whole-body 18F dopa PET for detection of gastrointestinal carcinoid tumors

PURPOSE

To evaluate fluorine 18 (18F) dopa positron emission tomography (PET) in comparison with established imaging procedures in gastrointestinal carcinoid tumors.

MATERIALS AND METHODS

After evaluation of the normal distribution of 18F dopa, 17 patients with histologically confirmed tumors were examined with 18F dopa PET. Results of 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG) PET, somatostatin-receptor scintigraphy, and morphologic imaging (computed tomography and/or magnetic resonance imaging) were available for all patients. Results of the procedures were evaluated by two radiologists and two nuclear medicine specialists, whose consensus based on all available histologic, imaging, and follow-up findings was used as the reference standard.

RESULTS

Ninety-two tumors were diagnosed: eight primary tumors, 47 lymph node metastases, and 37 organ metastases. 18F dopa PET led to 60 true-positive findings (seven primary tumors, 41 lymph node metastases, 12 organ metastases); FDG PET, 27 (two primary tumors, 14 lymph node metastases, 11 organ metastases); somatostatin-receptor scintigraphy, 52 (four primary tumors, 27 lymph node metastases, 21 organ metastases); and morphologic imaging, 67 (two primary tumors, 29 lymph node metastases, 36 organ metastases). This resulted in the following overall sensitivities: 18F dopa PET, 65% (60 of 92); FDG PET, 29% (27 of 92); somatostatin-receptor scintigraphy, 57% (52 of 92); morphologic procedures, 73% (67 of 92). Although the morphologic procedures were most sensitive for organ metastases, 18F dopa PET enabled best localization of primary tumors and lymph node staging.

CONCLUSION

18F dopa PET is a promising procedure and useful supplement to morphologic methods in diagnostic imaging of gastrointestinal carcinoid tumors.

Adenocarcinoma of the small bowel

Cancer of the small bowel is a rare entity but its incidence is rising. Historically, outcome is poor despite apparent curative resection. At present surgery remains the only treatment modality of proven benefit in the management of this disease. Recent data would suggest 5-year survival rates in the order of 40-50% at all sites of small bowel cancer. To improve upon this, earlier diagnosis with a high index of suspicion and multicentre adjuvant therapy trials are required.

Role of computerized tomography in the staging of gastrointestinal neoplasms

Gastrointestinal neoplasms are very common diseases, and the first challenge for clinicians is to define the extent of the tumor in order to plan the best treatment. The role of computerized tomography in assessing this kind of patient is well established worldwide. This article reviews the capabilities and the limits of this imaging technique in the staging of the tumors of the digestive tract (liver, gallbladder, biliary tract, pancreas, esophagus, stomach, small bowel, and colon).

CT and bowel disease

CT has now come of age in the detection and demonstration of bowel pathology and is likely to supplant traditional imaging techniques further in the future. Its role here has been greatly aided by the advent of fast spiral CT sequences and, with the development of even faster multidetector CT systems, this can only increase.

The role of dual-phase enhanced helical computed tomography in difficult intestinal bleeding

We report a case of leiomyoma of the small bowel presenting with massive gastrointestinal (GI) bleeding that was diagnosed using dual-phase enhanced helical computed tomography (CT) in the preoperative period. A 68-year-old man was admitted to our hospital because of recurrent rectal bleeding. Gastroduodenoscopic and total colonoscopic examination results were negative; however, the patient continued to show bloody stool. Dual-phase enhanced helical CT was subsequently performed. CT revealed a hypervascular tumor, with evident extravasation of the contrast medium in the bowel lumen. We were successful in establishing the point of bleeding. Exploratory laparotomy was performed the same day. A solid round extraluminal mass was found at the proximal jejunum. Bleeding was observed over the serosal side of this tumor and segmental resection of the tumorous small intestine was performed. Pathologic examination revealed leiomyoma. Enhanced helical CT proved to be useful in localizing active GI bleeding.

Dynamic CT in the preoperative evaluation of patients with gastric cancer: correlation with surgical findings and pathology

BACKGROUND

The use of diagnostic techniques in the preoperative staging of patients with gastric cancer must be better defined. To further clarify which technique is indicated, we applied a new modality of computed tomography (CT) scanning for patients with gastric cancer.

METHODS

Dynamic CT of the abdomen using water as oral contrast agent was performed in 30 patients with gastric adenocarcinoma. Patients without evidence of metastatic disease underwent exploratory laparotomy and intraoperative staging. Resectable patients had surgical excision and definitive pathologic staging.

RESULTS

Two patients (7%) had metastatic disease by CT and were considered inoperable. The remaining 28 underwent laparotomy. Of these, six (21%) were unresectable and 22 (79%) had surgical resection. Dynamic CT adequately suggested advanced stage disease in four (67%) of the 6 unresectable patients. Wall thickness in dynamic CT correlated with the risk of serosal involvement (P < .001). Both CT and surgery had an accuracy of 64% (P > .05) in predicting pathologic staging. CT overstaged only 4% of cases.

CONCLUSIONS

Dynamic CT is a useful modality that can indicate inoperable disease, obviating the need for laparotomy in patients with gastric adenocarcinoma. CT can modify the surgical approach by suggesting unresectable or advanced disease. The low percentage of patients that are overstaged by CT, combined with its similar staging accuracy when compared with laparotomy, support its preoperative use in these patients.

The accuracy of CT staging of small bowel adenocarcinoma: CT/pathologic correlation

PURPOSE

Several studies have documented the use of CT in the evaluation of small bowel neoplasms, but few have addressed the CT staging of adenocarcinoma. We retrospectively correlated CT and pathologic staging to evaluate the accuracy of CT for staging small bowel adenocarcinoma using American Joint Committee on Cancer criteria.

METHOD

The preoperative CT scans of 15 patients with pathologically proven small bowel adenocarcinoma were analyzed. Two blinded readers separately interpreted extent of invasion, presence of lymphadenopathy, and distant metastases. Pathologic and CT staging were compared.

RESULTS

The overall accuracy of CT staging was 47% (14/30). The sensitivity of detection of mesenteric infiltration was 88%. The sensitivity and specificity for detection of distant metastases were 58 and 63% and for lymphadenopathy 75 and 20%, respectively. Errors occurred in patients with Crohn disease, adenomas, Peutz-Jegher syndrome, small bowel obstruction, and perforation and on suboptimal studies.

CONCLUSION

The accuracy of CT staging of small bowel adenocarcinoma is 47%. CT is highly sensitive but not specific for the detection of mesenteric infiltration and regional lymphadenopathy. Since spiral CT may offer improved detection of distant metastases and increased accuracy in the evaluation of patients with concomitant bowel disease, further research is needed to determine the maximal utility of CT in the staging of adenocarcinoma of the small bowel.

Gastrointestinal carcinoid tumors: current management strategies

BACKGROUND

Carcinoid or neuroendocrine tumors of the gastrointestinal tract, although characteristically indolent, are also quite heterogeneous both with respect to histologic and endocrine features and with respect to clinical presentation and behavior.

PURPOSE

This study was undertaken to review and summarize the current literature on classification controversies, site-specific carcinoid presentation and behavior, and diagnostic and management strategies for primary and advanced carcinoid tumors and the carcinoid syndrome.

RESULTS

For carcinoid tumors, oncologic results depend on the location of the primary tumor, extent of locoregional and metastatic disease, functioning status of the tumor, and the feasibility of complete surgical extirpation. Whereas favorable survival rates are typically observed for appendiceal and rectal primaries, less favorable rates are often observed for colonic and ileal tumors. A search for additional tumors is generally advised because multiple carcinoids and second neoplasms are not uncommon. Because of the indolent nature of the tumor and because these therapies have been shown to improve quality and quantity of life, otherwise fit patients with advanced carcinoid disease should be treated with aggressive medical and surgical therapies. Development of a malignant carcinoid syndrome indicates the presence of a functionally active carcinoid tumor and portends a poor prognosis.

CONCLUSION

Gastrointestinal carcinoids, although malignant, behave differently from other carcinomas. Results are highly variable and must be individualized according to the site of the primary tumor, extent of spread, and general condition of the patient. A prolongation of quality life can often be accomplished through aggressive medical and surgical therapies.

Imaging of primary small intestinal tumours by enteroclysis and CT with pathological correlation

Preoperative diagnosis of primary small intestinal neoplasms can be a challenge for both clinicians and radiologists. As a result of their infrequent occurrence, they invariably present difficult problems in diagnosis and management. These problems are reflected mainly in the delayed treatment and a very poor prognosis for such malignant tumours. Their morphological changes, however, shown in enteroclysis and CT, correlate almost perfectly with the lesions identified in the gross pathological specimens. This ability to accurately image a small intestinal neoplasm, independently of its size, anatomical localization and growing tendency, represents a major improvement in the diagnosis and management of these neoplasms. This paper, based on a large series of patients with primary small intestinal neoplasms, focuses on the recognition of their detailed radiological appearances when evaluated by enteroclysis and CT.

Small bowel neoplastic disease: demonstration by MRI

This study demonstrates the appearance of small bowel tumors on MR images. Sixteen patients with tumors involving small bowel were studied by MRI. All tumors were proven with histopathology. Eleven patients had primary tumors of the small bowel, which included the following: four carcinoid tumors, three adenocarcinomas, two lymphomas, one leiomyosarcoma, and one leiomyoma. Five patients had recurrent or metastatic disease to small bowel: two patients had colon cancer, one patient had pancreatic cancer, one patient had uterine leiomyosarcoma, and one patient had chloroma (leukemia). MR examination included breath-hold T1-weighted spoiled gradient echo (all patients), immediate postgadolinium-spoiled gradient echo (10 patients), and 2 to 4 minutes postgadolinium T1-weighted, fat-suppressed images (all patients). Tumor size, local extent, signal intensity, and enhancement features of tumor and adjacent tissue were determined. Tumor ranged in diameter from 1 to 9 cm (mean, 4.0 cm). Tumors had similar signal intensity to normal small bowel on precontrast images. Fourteen malignant tumors showed heterogeneous enhancement greater than adjacent bowel on gadolinium-enhanced images. Tumor local extent was best shown on precontrast-spoiled gradient-echo images and postgadolinium T1-weighted fat-suppressed images. Image quality was most consistent on breath-hold images. The results of this study show that small bowel tumors are demonstrable on MR images. Precontrast breath-hold T1-weighted spoiled gradient-echo images and gadolinium-enhanced fat suppressed images demonstrate tumor extent most reliably.

CT of small-bowel neoplasms

The diagnosis of neoplasms of the small intestine remains a difficult challenge owing to their nonspecific clinical presentation. CT is an efficient and contributive tool in their diagnosis and preoperative staging. Enabled by CT, the evaluation of the intramural and extramural portions of such tumors complements the mucosal analysis allowed by barium examination. Strict technical rules should be applied to minimize pitfalls mainly resulting from insufficient bowel opacification. Although characteristic appearances are rare, typical CT findings may suggest a specific diagnosis where lipomas and carcinoid tumors are concerned.

Primary malignant lymphoma of the intestine

Primary intestinal lymphoma is uncommon but not rare. Its pathology and potential therapy are complex. Its epidemiology has changed radically over the past century, reflecting a sharp surge in the incidence of intestinal lymphoma, particularly that associated with immunosuppression. Recent advances in diagnosis, a new approach to pathologic classification by immunotyping, and a new staging system have influenced therapy. New multimodal therapeutic protocols have improved the prognosis of this once deadly disease.

Sonographic appearance of primary small bowel carcinoid tumor

BACKGROUND

To assess the value of sonography in the diagnostic work-up of small bowel carcinoid tumors and characterize their sonographic appearance.

METHODS

We retrospectively reviewed the sonographic findings (size, shape, echogenicity, contour, location, wall thickening, serosal transgression, vascularity) of all cases of carcinoid tumors investigated between January 1988 and January 1993. Six tumors, in five patients with histologic proof, were analyzed and, when possible, correlation with pathological or surgical results was made.

RESULTS

In four out of five cases, the tumor was not suspected clinically prior to sonography; in one case, a small synchronous lesion was only found at surgery. Its sonographic appearance was a hypoechoic, homogenous, predominantly intraluminal mass with smooth intraluminal contour and attached to the wall by a broad base with interruption of the submucosa and thickening of the muscularis propria in all cases. There were signs of serosal transgression in four cases, puckering and retraction in two cases, hypervascularity in two cases, and mesenteric involvement in three cases. All lesions were located in the ileum and the mean diameter was 22 x 17 mm.

CONCLUSION

Ultrasonography was useful in the detection of primary carcinoid tumors of small bowel. Their sonographic characteristics were described and some of them were highly suggestive of the diagnosis.

Current CT/MRI examination of the upper intestinal tract

When properly performed, CT of the abdomen can provide valuable information about mural diseases of the alimentary tract. It can demonstrate the digestive origin of an abdominal mass, categorize a given lesion on the basis of its specific CT appearance and any associated CT findings, assess the extramural spread of gastrointestinal lesion, guide various interventional procedures (biopsy, drainage) and follow a patient's response to therapy.