[Benign tumors of the stomach]

The term "benign gastric tumours" comprises three distinct entities: submucosal tumours, polyps and carcinoid tumours. Submucosal tumours are rare and most often conjunctive (leiomyoma, schwannoma, lipoma, etc.), but may also be heterotopic or congenital. Because of their subepithelial location, samples taken during endoscopic examination are rarely contributory. Endoscopic ultrasonography is the examination of reference for characterisation of these tumours. Polyps of epithelial origin, are common, most often small and without degenerative potential. They can be histologically diagnosed during endoscopic ultrasonography. Carcinoid tumours, which are very rare, are discussed elsewhere in this issue.

[Contribution of endosonography to the diagnosis and follow-up of pediatric gastric neurofibroma revealing von Recklinghausen's disease]

BACKGROUND

Gastrointestinal involvement in von Recklinghausen's disease (RD) is rare during childhood; its symptoms are late and its prognosis is poor, related to local recurrence and risk of malignant transformation.

CASE REPORT

A 13 year-old boy was admitted for hematemesis revealing gastric ulcer. A second episode of hematemesis led to identify a sessile gastric tumor in this patient having numerous skin café-au-lait spots. Recurrent bleeding required laparotomy that showed diffuse infiltration into the anterior gastric wall: histological examination of the excised piece showed characteristic features of neurofibromatosis. The patient was not compliant to the endosonographic survey so that a symptomatic relapse led to total gastrectomy: histological examination did not show malignant transformation.

CONCLUSION

Endoscopy is a major tool for identifying gastrointestinal localization of RD but endosonography is necessary to precise the extent of the tumor.

Endosonographic features of pancreatic metastases

BACKGROUND

Pancreatic metastasis is a rare event. Surgical resection can provide long-term survival in selected cases. The aim of this study was to describe the endosonographic features of pancreatic metastases.

METHODS

Among the 7000 endoscopic ultrasound (EUS) examinations of the pancreas performed between 1989 and 1993, 7 were performed in patients with pancreatic metastases that were histologically confirmed (6 by surgery, 1 by CT biopsy). Videotapes of the EUS procedures were re-examined. Metastases were from four renal cell carcinomas, one ovary carcinoma, one chondrosarcoma, and one neuroendocrine carcinoma of the gallbladder.

RESULTS

A solitary lesion was imaged by EUS in six cases and 10 lesions were seen in one case. Fifteen of 16 lesions were slightly hypoechoic or isoechoic in comparison with the adjacent pancreas. They were homogeneous, round, well circumscribed and were associated with an enhancement of the ultrasonic beam. The association of these ultrasonographic patterns was different from that usually observed in cases of primary pancreatic carcinoma. In one case (ovary carcinoma), the lesion was hypoechoic, with heterogeneous infiltration and indistinct margins and with the marked attenuation of the ultrasonic beam that is commonly noticed in primary pancreatic carcinoma or in focal chronic pancreatitis.

CONCLUSION

Endosonographic features of pancreatic metastasis are usually different from those observed in cases of pancreatic carcinoma.

Endoscopic ultrasonography for the preoperative localization of insulinomas

Preoperative radiological localization of insulinomas often fails because of the small size of the tumors. We studied retrospectively the value of different procedures in preoperative localization of insulinomas in 18 patients. Radiological assessment included transabdominal ultrasonography, computed tomography, angiography, magnetic resonance imaging, transhepatic venous sampling, and endoscopic ultrasonography (EUS) for the last 11 patients. During surgery, the association of palpation and intraoperative ultrasonography localized 16 solitary tumors and two multiple tumors (mean size, 1.8 +/- 1.1 cm). There insulinomas were found to be malignant. Conventional preoperative methods correctly localized the tumor in seven of 18 cases (38%), whereas the sensitivity of EUS was 10 of 11 cases (90%). Surgical procedures involved eight enucleations, nine distal pancreatectomies, and one total pancreatectomy. Because of its high sensitivity and safety, EUS was found to be the best method for preoperative localization of insulinomas, and we recommend that EUS replace conventional methods for the majority of cases.

[The measurement of PAF (platelet activating factor) in human saliva: standardization of the method]

The evaluation of the salivary PAF has possible by using the radio immuno assay method (RIA). We wanted to study the presence of such substance in the saliva under physiological conditions and particularly in relation to possible existence of a circadian rhythm or periodical oscillations. The work has been developed in two phases. In the first one we evaluated the daily salivary PAF amount while in the second phase of the study we verified the existence of a possible circadian rhythm. The results encouraged us to extend the study to the typical, different physiological aspects of such phospholipid having as objective the control of the salivary PAF amount in pathological conditions.

Interobserver agreement in endoscopic ultrasonography staging of esophageal and cardia cancer

BACKGROUND

Endoscopic ultrasonography has been accepted as an accurate means of staging cardioesophageal cancer, but no study has focused on the variability of interobserver interpretation of images so obtained.

METHODS

We compared interpretations recorded by five independent observers in 46 cases examined by endoscopic ultrasonography. One observer then reviewed a subset of 28 examinations 6 months later.

RESULTS

Interpretations were in nearly full accord for uT0 and uT4 tumors (kappa = > or = 0.73), in good accord for uT1 and uT3 tumors (kappa = > or = 0.42), but in poor accord for uT2 tumors (kappa = 0.16). Agreement was generally good when pertaining to invasion of adjacent organs, but no agreement was noted for invasion of the pericardium. In assessment of lymph node involvement, agreement was good for intra-abdominal, subcarinal, right lower paratracheal, and paraesophageal nodes (kappa = > or = 0.49), but poor for left lower and upper paratracheal lymph nodes. Intraobserver agreement was excellent for extent of tumor infiltration (kappa = 0.91) and good for lymph nodes (kappa > or = 0.51).

CONCLUSIONS

In staging cardioesophageal cancer by endosonographic ultrasonography, improvement is needed in cases of uT2 tumors and of tumors invading the pericardium, and in assessment of lymph nodes in the upper mediastinum.

Value of endoscopic ultrasonography in the diagnosis of common bile duct stones: comparison with surgical exploration and ERCP

An accurate and safe preoperative method of imaging the common bile duct is essential for the proper diagnosis of calculous biliary tract disease, especially in the current era of laparoscopic cholecystectomy. The value of endoscopic ultrasonography in detecting common duct stones has been reported, albeit in small series. The aim of this retrospective study was to assess the accuracy of EUS in a large series of patients. We compared EUS to direct cholangiography in the evaluation of 422 patients for common duct stones. Ductal stones were imaged by EUS in 168 patients (43.4%). No complications were encountered. EUS failed in 2.3% of cases, ERCP failed in 8.3%, and surgical exploration failed in 0.5%. Comparison of EUS with surgical exploration in 185 patients showed a sensitivity of 94.9%, a specificity of 97.8%, and an accuracy of 95.9%. EUS was compared to ERCP in 219 patients. All common duct stones found by ERCP were evident by EUS. Concordance was obtained in 91.3% of cases. Review of videotapes disclosed 3 false-positives and 16 unequivocal true-positives. We conclude that EUS is a safe and highly accurate means of detecting common duct stones and should be proposed before laparoscopic cholecystectomy in patients at risk of choledocholithiasis.

Interobserver variation in tumor staging

Interobserver agreement in cardioesophageal and rectal tumor evaluation is generally good, especially for uT1 and uT4 tumors. Diagnosis of a uT2 tumor is difficult and results in poor agreement. However, the proportion of agreement is satisfactory for distinguishing tumors that invade the mediastinal or the perirectal fat from those that do not, a situation that may be the most relevant from a therapeutic point of view. In cases of cardioesophageal tumor, agreement for metastatic LN is lower and depends on the sites involved, with the best agreement for intra-abdominal LN, which may indicate a worse prognosis. Lack of agreement in EUS images can be avoided by precise manipulation of the echoendoscope in the upper part of the mediastinum and by improving training and the definitions regarding EUS.

[Digestive echo-endoscopy]

Since its introduction into clinical practice in 1980, echo-endoscopy has greatly contributed to improving our capacity to image the digestive tract and now plays a major role in management of digestive tract diseases. Echo-endoscopy is a second intention technique reserved for further investigation of lesions previously identified by endoscopy or other imaging techniques. All five layers of the wall and surroundings of the accessible structures (oesophagus, stomach, duodenum, rectum and colon) can be visualized. Evaluation of locoregional extension of cancer invasion is one of the predominant indications. For example, since the prognosis of tumours of the oesophagus are directly related to parietal and lymph node extension, echo-endoscopy would be indicated to precisely determine the tumoural stage and thus help in adapting therapeutic management. Today, it is generally accepted that echo-endoscopy is superior to computed tomography for staging tumours of the oesophagus and the cardia. For gastric and duodenal adenocarcinomas, the performance of echo-endoscopy is similar and can identify more readily superficial lesions accessible for photocoagulation. For adenocarcinoma of the rectum, echo-endoscopy can be used to identify the tumoural stage and local extension and thus help in therapeutic decision making. Other classical indications include the evaluation of submucosal tumefaction and biliopancreatic disorders (biliary lithiasis, pancreatitis, tumours). Thus for certain well-defined indications, echo-endoscopy is now the highest performing imaging technique currently available for lesions of the digestive tract. Operator experience is however a limiting factor, emphasizing the need for clinical training.

Endoscopic ultrasonography in the staging and follow-up of epidermoid carcinoma of the anal canal

Epidermoid (squamous cell) carcinomas of the anal canal are relatively rare, accounting for less than 3% of all malignant tumors affecting the large intestine. Radiation therapy alone or combined with chemotherapy is the treatment of choice. To be effective, this requires initially correct staging and accurate follow-up. Endoscopic ultrasonography plays an essential role, which, during a period of 20 months, we applied to 20 patients. This made possible initial staging according to the TNM classification system. Follow-up examinations showed reduction in size of lesions in all cases. Three patients required early post-radiation surgical intervention because of rectal or vaginal invasion or lymph node metastases. Recurrence in 3 patients, evident by mural expansion on consecutive ultrasound examinations, was diagnosed at 6, 10, and 12 months. In all 6 patients requiring surgical intervention, good correlation was observed between ultrasonic images and operative findings.

Common bile duct stricture as a late complication of upper abdominal radiotherapy

We report the cases of two patients who developed symptomatic common bile duct stricture 10 years after upper abdominal radiotherapy for malignant lymphoma. Both patients were in complete remission and presented with marked obstructive jaundice. Endosonography was useful in both cases and showed segmental thickening of the bile duct wall narrowing in the lumen. Both patients underwent surgical exploration, confirming biliary obstruction due to intrinsic wall thickening, and had successful biliary drainage by Roux-en-Y hepatico-jejunostomy. Histological examination of the resected bile duct, in one case, and of a bile duct biopsy, in the other, was consistent with late irradiation injury. We conclude that stricture may be a delayed consequence of radiotherapy applied to normal bile ducts.

Diagnosis of choledocholithiasis by endoscopic ultrasonography

BACKGROUND/AIMS

Endoscopic ultrasonography is a promising procedure for the diagnosis of extrahepatic cholestasis. Accuracy for the diagnosis of choledocholithiasis by ultrasonography and computed tomography were prospectively compared with endoscopic ultrasonography in 62 consecutive patients.

METHODS

Final diagnosis was determined by endoscopic retrograde cholangiography with or without sphincterotomy or intraoperative cholangiography with or without choledochoscopy. All of the patients had abdominal ultrasonography, computed tomography, endoscopic ultrasonography, and either an endoscopic retrograde (n = 40) or intraoperative cholangiography (n = 32) performed.

RESULTS

Choledocholithiasis was confirmed in 22 patients. Thirteen patients had a stone with a diameter < 1 cm, and 14 had a nonenlarged common bile duct. Endoscopic ultrasonography was more sensitive (97%) than ultrasonography (25%; P < 0.0001) and computed tomography (75%; P < 0.02). Specificity and positive predictive value were not significantly different. Negative predictive value of endoscopic ultrasonography (97%) was better than that of ultrasonography (56%; P < 0.0001) and computed tomography (78%; P < 0.02). Results were unchanged after six patients in whom the absence of choledocholithiasis was considered probable after follow-up were excluded. Endoscopic ultrasonography results did not depend on stone diameter or common bile duct dilatation.

CONCLUSIONS

Endoscopic ultrasonography appears to be the best diagnostic tool for the diagnosis of choledocholithiasis compared with other noninvasive procedures.

[Place of ultrasound endoscopy in dysphagia]

Echo-endoscopy is a technique which has been shown to be effective in the staging of cancers of the oesophagus and cardia. It is indicated to guide the therapeutic choice according to the stage of regional extension, which is known to be the main prognostic factor of this disease. Echoendoscopy is a very elegant technique to visualise subepithelial vaulting, which can correspond either to a submucosal tumour, or to extrinsic compression by an adjacent organ or a mediastinal tumour infiltration. Echo-endoscopy can be useful to differentiate idiopathic megaoesophagus from secondary megaoesophagus by visualising a peri-oesophageal infiltration.

Endoscopic ultrasonography in the local staging of primary gastric lymphoma

Endoscopic ultrasonography (EUS) and endoscopy were prospectively performed and compared to the histopathologic findings of the resection specimens in 24 patients with primary gastric lymphoma (PGL). On EUS, three types of PGL could be differentiated, a superficial type (n = 10), an infiltrating type (n = 12) and a tumorous type (n = 2). In the correct assessment of surface extension of the tumors, endoscopy and EUS agreed in 37.5% of cases and EUS showed more extensive disease than endoscopy in 58% of cases. However, in comparison to the resection specimens, EUS still underestimated the tumor surface extension in 37.5% of cases; this was mainly in low grade malignant PGL. The depth of tumor infiltration was correctly determined on EUS compared to the resection specimens in 91.5% of cases. Sensitivity, specificity and accuracy of diagnosing lymph node metastases were 100%, 80% and 83%, respectively. We conclude that EUS is a useful pre-therapeutic staging tool for primary gastric lymphoma but there remain some problems in determining the longitudinal and circular tumor spread in order to accurately guide the extent of gastric resection.

Endoscopic ultrasonography in the diagnosis and staging of pancreatic adenocarcinoma. Results of a prospective study with comparison to ultrasonography and CT scan

Endoscopic ultrasonography (EUS) was compared to ultrasonography (US) and CT scan (CT) in order to evaluate its role in the diagnosis and the locoregional spread assessment of pancreatic cancer. Sixty-four patients suspected of pancreatic cancer were studied prospectively, and the results of imaging techniques were compared to histology and surgical exploration. There were 49 cases of pancreatic adenocarcinoma, 11 of pancreatitis, 2 of common bile duct carcinoma, 1 lymphoma and 1 hepatocellular carcinoma with peripancreatic metastatic lymph nodes. EUS was significantly more accurate (91%) than CT (66%) and US (64%) for diagnosis of pancreatic cancer. EUS was able to image all 7 cancers less than 25 mm in diameter, US and CT only one. There were 4 false positives with EUS which were all cases of pseudotumorous pancreatitis. For detecting lymph node involvement, EUS was significantly more sensitive (62%) and accurate (74%) than US (8% and 37%) and CT (19% and 42%), respectively. Invaded lymph nodes adjacent to large tumors and micrometastatic involvement were responsible for this lack of sensitivity. EUS was significantly more sensitive (100%) than CT (71%) and US (17%) for detecting venous involvement. The specificity of EUS was lower (67%) because of duodenal bulb stenosis and large tumors. In conclusion, this prospective and comparative study confirms that EUS is an accurate tool for diagnosis and locoregional spread assessment of pancreatic cancer when performed in a reference center. EUS is of particular interest for small tumours. However, EUS does not enable differentiation of pseudotumorous pancreatitis from adenocarcinoma.

[Pancreatic endocrine tumors: contribution of ultrasound endoscopy in the diagnosis of localization]

Endoscopic ultrasonography is a new imaging technique which has previously demonstrated its accuracy in localization of small pancreatic cancers. The aim of this retrospective study was to report our experience of this new method for localization of small endocrine tumors of potential pancreatic origin. Thirteen patients with insulinoma and 17 patients with Zollinger-Ellison syndrome were studied. All were imaged in a reference center by ultrasound (US) and CT scan (CT) before endoscopic ultrasonography. Insulinomas: 78.5% of tumors were 15 mm or less in size. The endoscopic ultrasonography was more accurate (79%) than US (7%) and CT (14%) for localization of the 14 tumors removed in the 13 patients who underwent surgery. Gastrinomas: Endoscopic ultrasonography was able to image 7 to the 9 pancreatic gastrinomas, the 2 duodenal gastrinomas, and the 2 gastrinomas located in peripancreatic lymph nodes which were removed in the 9 patients who underwent surgery. US and CT were able to image only one of the two peripancreatic lymph nodes. We concluded that endoscopic ultrasonography is a highly accurate tool for localization of small pancreatic endocrine tumors and should be performed early in the management of these tumors.

Localization of pancreatic endocrine tumors by endoscopic ultrasonography

BACKGROUND

After a pancreatic endocrine tumor has been diagnosed on the basis of clinical signs and the results of laboratory tests, localization of the tumor by the usual imaging procedures fails in as many as 40 to 60 percent of patients. Endoscopic ultrasonography, a sensitive test for small carcinomas of the pancreas, might also be useful in patients with endocrine tumors of the pancreas that cannot be localized by conventional methods.

METHODS

We studied 37 patients later shown to have 39 endocrine tumors of the pancreas who had negative results on transabdominal ultrasonography and CT. All the patients underwent endoscopic ultrasonography, and 22 also underwent selective angiography. All the tumors were confirmed by surgical excision and immunohistologic examination; they consisted of 31 insulinomas, 7 gastrinomas, and 1 glucagonoma, 0.5 to 2.5 cm (mean, 1.4 cm) in diameter. All but one of the patients were cured of their disease, as ascertained by at least six months of clinical and laboratory follow-up.

RESULTS

Using endoscopic ultrasonography, we were able to localize 32 of the 39 tumors (sensitivity, 82 percent); no tumor was incorrectly localized. The size of the tumors was very similar (within 2 mm) to that predicted by endoscopic ultrasonography. Among the 22 patients who underwent both angiography and endoscopic ultrasonography, ultrasonography was significantly more sensitive than angiography for tumor localization (sensitivity, 82 percent vs. 27 percent). Among 19 control patients without pancreatic endocrine tumors, endoscopic ultrasonography was negative in 18 (specificity, 95 percent).

CONCLUSIONS

Endoscopic ultrasonography is a highly sensitive and specific procedure for the localization of pancreatic endocrine tumors. It should be considered for the preoperative localization of such tumors once the clinical and laboratory diagnosis has been established.

Endoscopic ultrasonography in colorectal diseases

Since new flexible high-frequency ultrasound endoscopes are now available, the use of this technique in colorectal disease has been determined. Its role in the preoperative staging of rectal cancer, and in follow-up after surgery has been established, but its use in cases of anal cancer and in non-neoplastic rectal diseases still has to be demonstrated more precisely.