Utility of positron emission tomography/CT in the evaluation of small bowel pathology
ABSTRACT We describe the management principles and different roles of positron emission tomography (PET)/CT in the evaluation of patients with small bowel tumours (adenocarcinoma, gastrointestinal stromal tumour, lymphoma, metastases) from initial staging, monitoring response to treatment, to detection of recurrent disease. We also discuss the various non-malignant aetiologies of small bowel fludeoxyglucose (FDG) PET uptake, and other pitfalls in FDG PET/CT interpretation. Awareness of the imaging appearances of small bowel tumours, patterns of disease spread and potential PET/CT interpretation pitfalls are of paramount importance to optimise diagnostic accuracy.
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ABSTRACT: Lung cancer metastasizing to gastrointestinal (GI)-tract is a rare event. Gastric metastasis is usually asymptomatic but when mucosal in location it may cause symptoms as demonstrated in the current case. This report describes a 60-year old male who was admitted for evaluation of a left upper lobe lung mass with associated bilateral nodular opacities and mediastinal lymphadenopathy. After thorough work-up the diagnosis of advanced lung adenocarcinoma was made. During hospitalization period and prior to starting chemotherapy, he exhibited upper gastrointentinal bleeding. Esophagogastroduodenoscopy revealed an ulcerative lesion in the gastric corpus representing metastasis of the primary lung carcinoma that ensued from immunohistochemical analysis. Clinical, pathological and therapeutic aspects of this uncommon site of extrathoracic metastatic disease are discussed, emphasizing the importance of the immunohistochemistry in the differential diagnosis of lung carcinomas whether primary or secondary to the lung.Journal of gastrointestinal oncology 06/2013; 4(2):E11-5. DOI:10.3978/j.issn.2078-6891.2012.057
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ABSTRACT: 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.Nature Reviews Clinical Oncology 07/2013; 10(9). DOI:10.1038/nrclinonc.2013.132 · 14.18 Impact Factor
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ABSTRACT: Diarrhea is best defined as passage of loose stools, often with more frequent bowel movements. For clinical purposes the Bristol Stool Form Scale works well to distinguish stool form and to identify loose stools. Laboratory testing of stool consistency has lagged behind. Acute diarrhea is likely to be due to infection and to be self-limited. As diarrhea becomes chronic it is less likely to be due to infection; duration of one month seems to work well as a cut off for chronic diarrhea, but detailed scientific knowledge is missing about the utility of this definition. In addition to duration of diarrhea, classifications by presenting scenario, by pathophysiology, and by stool characteristics (e.g., watery, fatty, or inflammatory) may help the canny clinician refine the differential diagnosis of chronic diarrhea. In this regard, a careful history remains the essential part of the evaluation of a patient with diarrhea. Imaging the intestine with endoscopy and radiographic techniques is useful, and biopsy of the small intestine and colon for histologic assessment provides key diagnostic information. Endomicroscopy and molecular pathology are only now being explored for the diagnosis of chronic diarrhea. Interest in the microbiome of the gut is increasing; aside from a handful of well-described infections due to pathogens, little is known about alterations in the microbiome in chronic diarrhea. Serologic tests have well-defined roles in the diagnosis of celiac disease, but have less clearly defined application in autoimmune enteropathies and inflammatory bowel disease. Measurement of peptide hormones is of value in the diagnosis and management of endocrine tumors causing diarrhea, but these are so rare that these tests are of little value in screening since there will be many more false positives than true positive results. Chemical analysis of stools is of use in classifying chronic diarrhea and may limit the differential diagnosis that must be considered, but interpretation of the results is still evolving. Breath tests for assessment of carbohydrate malabsorption, small bowel bacterial overgrowth and intestinal transit are fraught with technical limitations that decrease sensitivity and specificity. Likewise, tests of bile acid malabsorption have had limited utility beyond empiric trials of bile acid sequestrants.Journal of Gastroenterology and Hepatology 10/2013; 29(1). DOI:10.1111/jgh.12392 · 3.50 Impact Factor