Gastrointestinal tissue diagnosis by laser-induced fluorescence spectroscopy at endoscopy

An endoscope-compatible, optical fiber system has been developed which can be used to obtain laser-induced fluorescence spectra of mucosal abnormalities during endoscopy in real time. The results of our previous in vitro studies have suggested that laser-induced fluorescence tissue spectra are sufficiently unique that they can be used to accurately diagnose mucosal abnormalities in some systems. To test this hypothesis in vivo, laser-induced fluorescence spectra were obtained during colonoscopy from 31 colonic adenomas, 4 hyperplastic polyps, and 32 examples of normal mucosa in 20 patients. The resulting spectra could be used to correctly differentiate adenomas from normal colonic mucosa and hyperplastic polyps in 97% of the specimens studied with the resulting sensitivity, specificity, and positive predictive value of 100%, 97%, and 94%, respectively. These results, although preliminary in nature, suggest that laser-induced fluorescence spectra can be used in the recognition and differential diagnosis of mucosal abnormalities at endoscopy.

Endoscopic ultrasound in the pre-operative staging of rectal carcinoma

Endoscopic ultrasound (EUS) was performed prospectively to stage 45 patients with rectal cancer. Patients were staged utilizing the TNM staging system. All patients subsequently underwent surgical resection with independent histopathologic staging. Depth of invasion was accurately predicted in 40 of 45 patients (89%). Presence or absence of lymph node metastasis was correctly determined in 34 of 45 patients (79%). EUS is an accurate method for local staging of rectal cancer.

Evaluation of submucosal upper gastrointestinal tract lesions by endoscopic ultrasound

The proper diagnosis of submucosal upper gastrointestinal tract mass lesions by endoscopy or barium study is difficult. Differentiation between submucosal tumors, vascular structures, and extrinsic organs is often impossible. We performed endoscopic ultrasound examination of 91 patients with upper gastrointestinal submucosal mass lesions. Endoscopic ultrasound was accurate in determining the site of origin in 48 of 50 cases where pathology or angiography comparison was available. Leiomyoma, lipoma, varices, and carcinoma had characteristic ultrasonographic findings. Endoscopic ultrasound is a useful procedure in the evaluation of upper gastrointestinal submucosal mass lesions.

Endoscopic ultrasonography in the diagnosis of pancreatic tumors

Endoscopic ultrasonography (EUS) can provide high resolution images of the pancreatic parenchyma. Complete visualization of the pancreas requires scanning from positions in the duodenum and stomach. Current clinical experience indicates that EUS is a useful adjunct to standard imaging in the evaluation of suspected pancreatic tumors. Improvements in technique and instruments are necessary to broaden the clinical application of EUS in pancreatic disease.

Evaluation of submucosal upper gastrointestinal tract lesions by endoscopic ultrasound

The proper diagnosis of submucosal upper gastrointestinal tract mass lesions by endoscopy or barium study is difficult. Differentiation between submucosal tumors, vascular structures, and extrinsic organs is often impossible. We performed endoscopic ultrasound examination of 91 patients with upper gastrointestinal submucosal mass lesions. Endoscopic ultrasound was accurate in determining the site of origin in 48 of 50 cases where pathology or angiography comparison was available. Leiomyoma, lipoma, varices, and carcinoma had characteristic ultrasonographic findings. Endoscopic ultrasound is a useful procedure in the evaluation of upper gastrointestinal submucosal mass lesions.

Endoscopic evaluation of the patient with esophageal carcinoma

Endoscopy provides an accurate method for diagnosis of esophageal carcinoma. Strategies for surveillance of patients with Barrett's esophagus by endoscopic biopsy are available and will hopefully improve our ability to diagnose early stage adenocarcinoma. No well-defined high-risk group for squamous cell carcinoma exists that would justify routine endoscopic surveillance. Careful attention should be paid to subtle changes in mucosal topography and color, which may suggest early squamous carcinoma in older patients undergoing diagnostic endoscopy. Further research is necessary to define what role if any vital dye staining has in screening of patients in the United States for esophageal cancer.

Adenocarcinoma of the esophagus and gastroesophageal junction. Clinical and pathologic assessment of response to induction chemotherapy

A preoperative induction chemotherapy regimen consisting of two monthly courses of etoposide, doxorubicin, and cisplatin was given to 13 patients with nonmetastatic adenocarcinoma of the distal esophagus or gastroesophageal junction. Esophageal ultrasound examination was performed both before chemotherapy and again before surgery. Induction chemotherapy was poorly tolerated with 10 of the 13 patients experiencing at least one episode of severe neutropenia. Two of the 13 patients refused the second course of treatment. A symptomatic response to chemotherapy, defined as a reduction in the presenting symptom, was noted in 10 of the 13 patients (77%). Endoscopic improvement occurred in 9 of the 13 patients (69%). Esophageal ultrasound evidence of a reduction in either T or N stage was noted in only 2 of the 13 patients (15%), however, and neither of these responses was confirmed pathologically. Clinical evidence of disease progression was noted in 4 patients during chemotherapy. With a median follow-up of 31 months, the relapse-free and overall survivals are 25% and 31%, respectively. Despite significant toxicity, our chemotherapy regimen would be considered successful if assessed by symptomatic or esophagoscopic improvement. Esophageal ultrasound, careful pathologic staging, and our disappointing survival rates, however, suggest limited, if any, value for this approach.

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.

Esophageal carcinoma: esophageal ultrasound assessment of preoperative chemotherapy

The effect of preoperative chemotherapy in the treatment of esophageal carcinoma is difficult to assess because of the inadequacies of clinical staging. Endoscopic esophageal ultrasound (EUS) has been shown to be accurate in the clinical determination of depth of tumor invasion (T) and regional lymph node status (N). Therefore, EUS may be useful in assessing the effect of preoperative chemotherapy in the treatment of esophageal carcinoma. Eleven patients with operable adenocarcinoma of the esophagus or esophagogastric junction underwent staging by EUS before treatment. This was followed by two courses (10 patients) or one course (1 patient) of chemotherapy: etoposide, 120 mg/m2 for 3 days; doxorubicin hydrochloride, 20 mg/m2; and cisplatin, 100 mg/m2. Restaging by EUS was done after treatment. Ten patients then underwent resection of the tumor with lymphadenectomy. One patient was found to have metastatic disease at thoracotomy and did not undergo resection. However, tissue sampling was adequate for the determination of pathological stage. Independent pathological determinations of T and N were then obtained. On completion of chemotherapy, 9 patients (82%) had relief or reduction of preoperative symptoms, and 9 patients (82%) had either no evidence of tumor or reduction of tumor size by endoscopy. Despite this clinical and endoscopic response, no patient had EUS-documented and pathology-confirmed reduction of T. However, 2 patients had EUS-documented and pathology-confirmed progression of N. The accuracy of EUS in the determination of T was 82% and of N, 73%.(ABSTRACT TRUNCATED AT 250 WORDS)

Esophageal ultrasound and the preoperative staging of carcinoma of the esophagus

Esophageal ultrasound allows the esophageal wall to be viewed as five discrete layers. Lymph nodes are easily identified, and their size, shape, margin, and internal structure can be assessed. This provides an alternative method of preoperative (clinical) evaluation of the primary tumor [T] and the regional lymph nodes [N] of patients with carcinoma of the esophagus. Esophageal ultrasound was attempted in the clinical staging of 28 patients with carcinoma of the esophagus. Six patients (21%) were not assessed because of the inability to pass the esophageal ultrasound probe through the malignant stricture. The staging system for carcinoma of the esophagus developed by the International Union Against Cancer and the American Joint Committee on Cancer was used. Twenty-two patients had the true T determined by pathologic review of the resected esophagus. Esophageal ultrasound correctly identified T in 13 patients (59% accuracy). In four patients (18%) the disease was overstaged by esophageal ultrasound; all these patients had early T1 tumors confined to the submucosa. In five patients (23%) the disease was understaged by esophageal ultrasound; all of these patients had advanced tumors (four T3 and one T4) that invaded beyond the esophageal wall. Seven of the nine incorrect esophageal ultrasound determinations were called T2 (three T1, three T3, one T4), which suggests that the borders of the muscularis propria require careful attention when evaluated by esophageal ultrasound. Twenty patients had the true N determined by pathologic review of the resected specimen. Esophageal ultrasound correctly identified N in 14 patients (70% accuracy). Three patients were falsely identified as having N1 disease and three were falsely identified as having N0 disease. The sensitivity, specificity, positive predictive value, and negative predictive value for N assessment by esophageal ultrasound were 70%. Esophageal ultrasound provides an alternative method of visualization of the esophageal wall and regional lymph nodes. Our early experience shows promise for esophageal ultrasound in the clinical staging of carcinoma of the esophagus.

Palliation of malignant esophageal obstruction

Progressive dysphagia is common in patients with advanced esophageal carcinoma. Multiple nonsurgical techniques are available to provide palliation and improved nutrition. Simple dilatation is the oldest technique and newer methods may offer greater efficacy. Laser therapy now provides an excellent opportunity to treat obstructing tumors. Placement of an esophageal prosthesis may become particularly useful when dilatation must be performed too frequently or has become ineffective or in the patient with an esophageal-pulmonary fistula. Newer techniques including BICAP tumor probe, intracavitary radiotherapy, or absolute alcohol injection offer promise. This review discusses the advantages and disadvantages of these different palliative techniques for patients with the extremely poor prognosis associated with esophageal cancer.

Erroneous Thiobarbituric Acid Values in Fish Tissues Caused by Their Normal Content of Free Iron

Erroneously high TBA values were obtained from liver, dark muscle, and certain other organs taken from seven species of sea fish. This error was eliminated by carrying out a portion of the test under anaerobic conditions or, more simply, by adding a mixture of EDTA and propyl gallate to the tissues immediately before the test is carried out. The error in the TBA values from the white muscle of lean fish and from whole cod fillets was found to be extremely small.By adding measured amounts of iron to white muscle immediately before testing it was found that from 1 to 20 ppm Fe++ was sufficient to cause extensive errors in the TBA values. Schoenmakers and Tarladgis have recently reported that up to 5000 ppm Fe+++ can be added to methyl linolenate and several vegetable oils without changing the TBA values. It is suggested that this apparent contradiction is the result of the differences in the substrates used. Marine oils contain more highly unsaturated fatty acids and the tissues contain other biologically active compounds capable of reacting with the oxidizing lipids.