Introduction: colon cancer is one of the main causes of cancer death. Diagnosis requires the examination of the entire large bowel by means of radiological or endoscopic techniques. Many patients suspect of colon cancer are referred for colonoscopy but nevertheless this suspicion is not confirmed after endoscopic examination. The objective of this study is the evaluation of the reliability of abdominal ultrasound in the diagnosis of these tumors.Material and method: we selected patients suspect of colon cancer referred to the endoscopy unit for a colonoscopy. An abdominal ultrasound was carried out on all patients prior to the endoscopy. Considering the endoscopic examination as a gold standard, the sensibility, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the ultrasonography were evaluated. Likewise, a series of analytical and clinical parameters were evaluated, in an attempt to establish associated factors of a colon cancer. The statistical analysis was carried out by means of the statistical package SPSS 12.0 for Windows.Results: 145 patients were included in the study (56.6% males) with an average 66.72 years of age (22-89). A cancer was diagnosed in 42 cases (28.9%). In the diagnosis of colon cancer, abdominal ultrasound presents a sensitivity of 79.06%, a specificity of 92.15%, a PPV and a NPV of 80.9% and of 91.2%, respectively. Excluding from the analysis lesions of the rectal ampulla, which cannot be adequately evaluated by means of ultrasound, the figures for sensitivity, specificity, PPV and NPV increase to 91.8, 92.1, 80.9 and 96.9% respectively. The univariate analysis showed that an age over 65 years and the presence of microcytosis are associated to a greater risk of colon cancer while after multivariate analysis only the presence of microcytosis resulted to be an independent predictive factor of cancer.Conclusions: abdominal ultrasound presents high sensitivity, specificity, PPV and NPV in the diagnosis of colon cancer. The combination of an ultrasonography and a rectoscopy permits us to rule out the presence of a colorectal carcinoma. In patients with microcytosis of 65 years and over, if there is strong clinical suspicion, a negative ultrasound may not be sufficient to rule out a colorectal neoplasia.

The endoscopic resection of submucosal tumors is a safe and efficient technique: It has few associated complications and allows diagnosis in all the cases and cure of the lesion in the great majority of cases.

Introduction: usually found in the gastrointestinal tract, carcinoids are the most frequent neuroendocrine tumors. Most of these lesions are located in areas that are difficult to access using conventional endoscopy (small intestine and appendix); carcinoid tumors found in the gastroduodenal tract and in the large intestine can be studied endoscopically; in these cases, if localized disease is confirmed, local treatment by endoscopic resection may be the treatment of choice. Since endoscopic ultrasonography has been shown to be the technique of choice for the study of tumors exhibiting submucosal growth, the selection of patients who are candidates for a safe and effective local resection should be based on this technique. Patients and method: we selected patients with gastrointestinal carcinoid tumors who were endoscopically treated between 1997 and 2002. Those patients with tumors measuring less than 10 mm, which had not penetrated the muscularis propria, and those with localized disease were considered candidates for endoscopic resection. The endpoints of this study were to assess the effectiveness (complete resection) and safety (complications) of the technique. Follow-up consisted of eschar biopsies performed one month and twelve months after the resection. Results: during the aforementioned period, we resected endoscopically 24 tumors in 21 patients (mean age: 51.7 years; 71.5% males). Most lesions were incidental discoveries made during examinations indicated for other reasons. Resection was indicated in most cases as a result of the suspected presence of a carcinoid tumor after endoscopic ultrasonography. Endoscopic ultrasonography also enabled us to clearly identify the layer where the lesion had originated, as well as the size of the lesion. The carcinoid tumor was removed in 13 cases (54.2%) by using the conventional snare polypectomy technique, in 9 cases (37.5%) assisted by a submucosal injection of saline solution and/or adrenaline, and in 2 cases (8.3%) after ligating the lesion with elastic bands. In all cases the resection was complete, with no recurrence during the follow-up period, and no major complications, except for a single case in which a post-polypectomy hemorrhage occurred that was endoscopically solved. Conclusions: in properly selected patients, the endoscopic resection of carcinoid tumors is a safe and effective technique that permits a complete resection in all cases with few complications. Endoscopic ultrasonography is the technique of choice for selecting the patients who are candidates for endoscopic resection.

Endoscopy with biopsy sampling is the gold standard used in gastric cancer diagnosis. However, the positive predictive value of signs and symptoms for the diagnosis of carcinomas is quite limited, and, therefore, many patients are subjected to non-diagnostic endoscopies, especially when symptoms are not so specific. This study shows that ultrasonography is sensitive enough for the diagnosis of gastric cancer, and, therefore, use of this technique would further ensure a better selection of patients for endoscopy. The study included 143 patients (86 men and 57 women, with an average age of 68.6 years) who were suspected of having gastric cancer. The diagnostic accuracy of ultrasonography was evaluated in a blind study. The conventional technique was used in all cases. Demographic parameters and a series of other clinical-analytical variables were studied to look for possible gastric cancer predictive factors, which when present would make ultrasonographic results irrelevant. Statistical analysis was done using SPSS 12.0, wherein a value of P < 0.05 was considered to be statistically significant. Of the 143 patients studied, 40 were diagnosed to have gastric cancer. Sonography was able to diagnose 37 cases correctly, while there were three false negative findings and eight false positive findings. This results in 92.5% sensitivity, 92.2% specificity, 82.2% positive predictive value, 96.9% negative predictive value, and a global accuracy of 92.3%. Univariate analysis showed that persistent vomiting (P = 0.021), hemoglobin level of less than 8 g/dl (P = 0.045) and a positive ultrasonography result (P < 0.0001) were associated with a higher frequency of gastric cancer. Multivariate analysis showed that persistent vomiting, with an odds ratio for gastric cancer of 3.68 (95% confidence interval 1.15-11.79; P = 0.039), and a positive ultrasonography result, with an odds ratio for gastric cancer of 117.78 (95% confidence interval 32.45-427.49; P < 0.0001), could be considered as independent predictive factors for gastric cancer. It was concluded that ultrasonography is a very sensitive and specific technique for diagnosing gastric cancer. Gastric cancer was found to be present in just 28% of the patients studied, and their condition was suspect because of the clinical manifestations. Only vomiting and a positive ultrasonography result can be considered as independent predictive factors of gastric cancer.

Introduction: the preoperative diagnosis of submucosal lesions in the gut may be complicated. Conventional endoscopy does not allow to clearly establishing a diagnosis, and does not adequately assess lesion size. Furthermore, endoscopic biopsy is usually not diagnostic. Cytology as performed by means of fineneedle puncture does not have enough sensitivity and specificity to be considered the gold standard in the diagnosis of these lesions. We will now assess the usefulness of endoscopic ultrasonography in the study of submucosal digestive tumors.Materials and methods: we have prospectively collected ultrasonographic studies from all the patients with submucosal tumors who were treated surgically. We assessed the sensitivity and specificity of this technique in the diagnosis of malignancy in said lesions, alongside factors that predict malignant behavior with the highest reliability. We also valued the reliability of ultrasound endoscopy in the assessment of lesion size and the wall layer where lesions are located. The results of histological studies were considered the gold standard.Results: the average size of lesions as measured by ultrasound endoscopy was 37.42 mm, with no significant differences in surgical piece: 38.98 (p = 0.143). However, conventional endoscopy underestimates the size of lesions. Endoscopic ultrasonography was able to adequately establish the origin layer of lesions in all cases. Sensitivity, specificity, positive predictive value, and negative predictive value of ultrasound endoscopy in the diagnosis of malignancy were 89.5, 90.9, 89.5, and 90.9%, respectively. In the univariate analysis, the ultrasonographic characteristics associated with a diagnosis of malignancy included presence of ulceration (p = 0.043), size above 4 cm (p = 0.049), irregular edges of lesion (p = 0.0001), a heterogeneous ultrasonographic pattern (p = 0.002), and the presence of cystic areas above 2 mm (p = 0.012). In the multivariate analysis, the last three factors were considered independent predictive factors for malignancy.Conclusions: endoscopic ultrasonography has a great sensitivity and specificity in the diagnosis of malignancy regarding sub-mucosal lesions. The irregularity of lesion borders, a heterogeneous ultrasonographic pattern, and the presence of cystic areas above 2 mm in size were considered independent predictive factors for malignancy.