Regional lymph node metastasis in gastric cancer: evaluation with endoscopic US

Historical perspective on needle development: From the past to the future

With the introduction of EUS, endoscopy was no longer limited to luminal indications. However, the method was unable to distinguish malignant from benign lesions. Consequently, needles designed for tissue acquisition under EUS-guidance was designed. Initially, the needles were designed for fine needle aspiration (FNA); nevertheless, with increased requirement for the precured tissue in terms of quality and quantity, newly design needles aimed at obtaining tissue cores for histological assessment were developed. Recent studies demonstrate superiority of these fine needle biopsy needles (FNB) compared to FNA needles.

Diagnostic accuracy of endoscopic ultrasonography (EUS) for the preoperative locoregional staging of primary gastric cancer

BACKGROUND

Endoscopic ultrasound (EUS) is proposed as an accurate diagnostic device for the locoregional staging of gastric cancer, which is crucial to developing a correct therapeutic strategy and ultimately to providing patients with the best chance of cure. However, despite a number of studies addressing this issue, there is no consensus on the role of EUS in routine clinical practice.

OBJECTIVES

To provide both a comprehensive overview and a quantitative analysis of the published data regarding the ability of EUS to preoperatively define the locoregional disease spread (i.e., primary tumor depth (T-stage) and regional lymph node status (N-stage)) in people with primary gastric carcinoma.

SEARCH METHODS

We performed a systematic search to identify articles that examined the diagnostic accuracy of EUS (the index test) in the evaluation of primary gastric cancer depth of invasion (T-stage, according to the AJCC/UICC TNM staging system categories T1, T2, T3 and T4) and regional lymph node status (N-stage, disease-free (N0) versus metastatic (N+)) using histopathology as the reference standard. To this end, we searched the following databases: the Cochrane Library (the Cochrane Central Register of Controlled Trials (CENTRAL)), MEDLINE, EMBASE, NIHR Prospero Register, MEDION, Aggressive Research Intelligence Facility (ARIF), ClinicalTrials.gov, Current Controlled Trials MetaRegister, and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), from 1988 to January 2015.

SELECTION CRITERIA

We included studies that met the following main inclusion criteria: 1) a minimum sample size of 10 patients with histologically-proven primary carcinoma of the stomach (target condition); 2) comparison of EUS (index test) with pathology evaluation (reference standard) in terms of primary tumor (T-stage) and regional lymph nodes (N-stage). We excluded reports with possible overlap with the selected studies.

DATA COLLECTION AND ANALYSIS

For each study, two review authors extracted a standard set of data, using a dedicated data extraction form. We assessed data quality using a standard procedure according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. We performed diagnostic accuracy meta-analysis using the hierarchical bivariate method.

MAIN RESULTS

We identified 66 articles (published between 1988 and 2012) that were eligible according to the inclusion criteria. We collected the data on 7747 patients with gastric cancer who were staged with EUS. Overall the quality of the included studies was good: in particular, only five studies presented a high risk of index test interpretation bias and two studies presented a high risk of selection bias.For primary tumor (T) stage, results were stratified according to the depth of invasion of the gastric wall. The meta-analysis of 50 studies (n = 4397) showed that the summary sensitivity and specificity of EUS in discriminating T1 to T2 (superficial) versus T3 to T4 (advanced) gastric carcinomas were 0.86 (95% confidence interval (CI) 0.81 to 0.90) and 0.90 (95% CI 0.87 to 0.93) respectively. For the diagnostic capacity of EUS to distinguish T1 (early gastric cancer, EGC) versus T2 (muscle-infiltrating) tumors, the meta-analysis of 46 studies (n = 2742) showed that the summary sensitivity and specificity were 0.85 (95% CI 0.78 to 0.91) and 0.90 (95% CI 0.85 to 0.93) respectively. When we addressed the capacity of EUS to distinguish between T1a (mucosal) versus T1b (submucosal) cancers the meta-analysis of 20 studies (n = 3321) showed that the summary sensitivity and specificity were 0.87 (95% CI 0.81 to 0.92) and 0.75 (95% CI 0.62 to 0.84) respectively. Finally, for the metastatic involvement of lymph nodes (N-stage), the meta-analysis of 44 studies (n = 3573) showed that the summary sensitivity and specificity were 0.83 (95% CI 0.79 to 0.87) and 0.67 (95% CI 0.61 to 0.72), respectively.Overall, as demonstrated also by the Bayesian nomograms, which enable readers to calculate post-test probabilities for any target condition prevalence, the EUS accuracy can be considered clinically useful to guide physicians in the locoregional staging of people with gastric cancer. However, it should be noted that between-study heterogeneity was not negligible: unfortunately, we could not identify any consistent source of the observed heterogeneity. Therefore, all accuracy measures reported in the present work and summarizing the available evidence should be interpreted cautiously. Moreover, we must emphasize that the analysis of positive and negative likelihood values revealed that EUS diagnostic performance cannot be considered optimal either for disease confirmation or for exclusion, especially for the ability of EUS to distinguish T1a (mucosal) versus T1b (submucosal) cancers and positive versus negative lymph node status.

AUTHORS' CONCLUSIONS

By analyzing the data from the largest series ever considered, we found that the diagnostic accuracy of EUS might be considered clinically useful to guide physicians in the locoregional staging of people with gastric carcinoma. However, the heterogeneity of the results warrants special caution, as well as further investigation for the identification of factors influencing the outcome of this diagnostic tool. Moreover, physicians should be warned that EUS performance is lower in diagnosing superficial tumors (T1a versus T1b) and lymph node status (positive versus negative). Overall, we observed large heterogeneity and its source needs to be understood before any definitive conclusion can be drawn about the use of EUS can be proposed in routine clinical settings.

Has the accuracy of preoperative diagnosis improved in cases of early-stage gastric cancer?

BACKGROUND

Adequate preoperative evaluation for gastric cancer staging is essential to develop an individualized treatment strategy involving surgery with reduced lymphadenectomy and laparoscopic gastrectomy.

METHODS

A total of 509 gastric cancer patients with clinical Stage IA or IB disease were divided into two groups: 304 patients were admitted in 2000 or earlier (Group A), and 205 patients were admitted in 2001, when multidetector computed tomography (MD-CT) was available, or later (Group B). We evaluated the accuracy of the preoperative diagnoses of tumor depth, lymph node involvement, and tumor stage.

RESULTS

With respect to tumor depth, 94.5 and 52.8% of patients were staged correctly in cT1 and cT2 patients, respectively. Among both cT1 and cT2 patients, the underestimated rates were lower in Group B than in Group A. For nodal metastasis, 83.2 and 30.0% of patients were staged correctly in cN0 and cN1 patients, respectively. Among the cN0 patients, 82.1 and 84.7% of Group A and Group B patients, respectively, were staged correctly. Among the cN1 patients, none of the patients in Group B was underestimated, while 9.7% of Group A patients were underestimated. There was a significant increase in the percentage of correctly staged patients and a decrease in the percentage of underestimated patients in Group B in comparison to Group A in both cStage IA and cStage IB patients.

CONCLUSIONS

Remarkable advances have been observed in the accuracy of preoperative staging in the early stage of gastric cancer. However, it is necessary to continue to develop accurate preoperative and intraoperative diagnostic systems.

Value of multidetector-row computed tomography in the preoperative T and N staging of gastric carcinoma: a large-scale Chinese study

OBJECTIVES

To investigate the value of multidetector-row computed tomography (MDCT) in the preoperative T and N staging of gastric carcinoma and to further investigate the clinicopathological factors affecting the diagnostic accuracy.

METHODS

Seven hundred ninety gastric carcinoma patients underwent preoperative MDCT examination. The results of MDCT were compared with surgical and pathological findings.

RESULTS

Early gastric carcinoma patients whose primary tumor was detected by MDCT had higher incidence of lymph node metastasis, larger tumor size, and deeper invasion. The overall accuracy of MDCT in determining T stage of gastric carcinoma was 73.80% (T1 45.93%, T2 53.03%, T3 86.49%, and T4 85.79%). The overall accuracy of MDCT in preoperative N staging was 75.22% (N0 76.17%, N1 68.81%, and N2 80.63%). The overall diagnostic sensitivity, specificity, and accuracy of MDCT for determining lymph node metastasis was 86.26%, 76.17%, and 82.09%, respectively. Multivariate analysis showed that the diagnostic sensitivity of MDCT in determining lymph node metastasis related with tumor size, N stage, and number of metastatic lymph nodes.

CONCLUSIONS

The clinical value of MDCT in the preoperative T and N staging of gastric carcinoma is relatively high. MDCT can be the first choice for the preoperative evaluation of patients with gastric carcinoma.

MRI of gastric carcinoma: Results of T and N-staging in an in vitro study

AIM: To determine the accuracy of 1.5-T magnetic resonance imaging (MRI) in the evaluation of gastric wall invasion and perigastric lymph node metastasis in gastric adenocarcinoma.

METHODS: Twenty resected gastric specimens containing 20 tumors were studied with a 1.5-T MR system using a commercial head surface coil. MR scanning was performed with a T1 weighted image (TR/TE = 500/20), and a T2 weighted image (TR/TE = 2500/90). MR findings were compared with pathologic findings.

RESULTS: A T1-weighted image demonstrated three layers in the normal gastric wall. All of the gastric tumors were well demonstrated by lesions and location. In a MRI findings of gastric wall invasion, there was 1 case of T1, 7 of T2, 11 of T3. Pathologic results of resected specimens included 3 cases of pT1, 4 of pT2, and 12 of pT3. The accuracy of T staging with MRI was 74% (14 of 19). MRI findings of lymph node metastasis included 6 cases of N0, 13 cases of N1. The accuracy of the N staging with MRI was 47% (9 of 19).

CONCLUSION: MRI has a high diagnostic accuracy in the evaluation of the T staging of gastric cancer in vitro and thus potentially enables preoperative histopathologic staging.

Prediction of recurrence of early gastric cancer after curative resection

BACKGROUND

Recurrence of early gastric cancer (EGC) after curative resection is rare, and the types of EGC that may recur have not been well studied. We attempted to create a system for predicting recurrence of EGC after R0 resection.

METHODS

From January 1987 to April 2005, 2,923 patients with EGC who underwent curative resection were retrospectively studied. Of them, 79 patients (2.7%) experienced recurrence. Logistic regression was performed to identify independent risk factors for overall recurrence and early recurrence (recurred within 24 months after resection) of EGC. A nomogram was developed on the basis of a Cox regression.

RESULTS

Median time to recurrence was 20.5 months, and early recurrence accounted for 60.7% of instances. Presence of lymph node metastasis and elevated gross type were independent risk factors for overall recurrence; patients with both identified risk factors had a higher recurrence rate than average level (17.5% vs. 2.7%, P < 0.001). Meanwhile, male gender, elevated gross type, and presence of lymph node metastasis were significantly associated with early recurrence, and in patients with all of the aforementioned identified risk factors, the early recurrence rate was higher (12.2% vs. 1.6%, P < 0.001). A nomogram for predicting the disease-free survival after operation was constructed. Its c-index was 0.79 and it appeared to be accurate.

CONCLUSIONS

Recurrence of EGC after curative resection can be predicted by using common clinical characteristics. Patients at high risk of overall and early recurrence could be identified; individual disease-free survival was predictable by the internally validated nomogram.

Helical CT evaluation of the preoperative staging of gastric cancer in the remnant stomach

OBJECTIVE

The objective of our study was to evaluate the diagnostic performance of helical CT for evaluating the preoperative staging of gastric cancer in the remnant stomach.

MATERIALS AND METHODS

Preoperative helical CT images of 67 patients with gastric cancer in the remnant stomach were independently analyzed regarding staging of the tumor by two radiologists who were blinded to histopathologic and surgical results. The differences in their assessments were resolved by consensus including the opinion of a third radiologist. The radiologists were asked to determine the depth of tumor invasion of the gastric wall (T stage), classifying it as </= T2, T3, or T4; local lymph node involvement (N stage); and solid organ metastasis or peritoneal involvement (M stage). TNM staging on CT was correlated with the histopathologic results of the resected specimen or with the surgical findings. Interobserver agreement was assessed using weighted kappa statistics.

RESULTS

The overall accuracy of T staging for reviewers 1 and 2 and for the consensus reading were 83.6%, 78.2%, and 85.4%, respectively. Five of 34 </= T2 lesions were misdiagnosed as T3. The cause of the overstaging was the misconception of the postoperative fibrotic change of the anastomotic site as perigastric tumoral infiltration. Three of 18 T4 lesions were understaged because of inadequate gastric distention (n = 1) and misinterpretation of adjacent organ involvement as partial volume averaging (n = 2). The accuracy of N staging and M staging were 81.8% and 94.0% for reviewer 1; 78.2% and 91.0% for reviewer 2; and 81.8% and 94.0% for the consensus reading, respectively. The weighted kappa values of T staging, N staging, and M staging were 0.676, 0.619, and 0.924, respectively.

CONCLUSION

Contrast-enhanced helical CT can be used successfully to preoperatively evaluate the staging of remnant stomach cancer in patients who have undergone previous gastric resection.

Ecoendoscopia na avaliação pré-operatória do estádio em doentes com câncer gástrico: correlação com os achados cirúrgicos e/ou histopatológicos

RACIONAL: O câncer gástrico é a maior causa de morte por câncer no Brasil. Na avaliação do prognóstico e no planejamento da terapêutica, é importante determinar o estádio e classificá-lo em TNM. OBJETIVO: Estudar os resultados da ecoendoscopia na determinação pré-operatória das categorias T e N. MÉTODOS: Foram examinados prospectivamente e de forma consecutiva 30 pacientes com adenocarcinoma gástrico no período de 1 ano. Utilizou-se o aparelho Olympus GIF-UM-20. Após seu posicionamento na terceira porção duodenal, estudaram-se as estações linfonodais 16, 13, 12, 6, 5, 4, 3, 8, 7, 9, 10, 11, 1 e 2, usando a freqüência de 7,5 MHz. Os resultados T e N foram comparados com os achados cirúrgicos e/ou histopatológicos. Nos casos irressecáveis, a correlação foi feita com os achados macroscópicos. Para a análise estatística utilizou-se o teste de correlação coeficiente kappa. RESULTADOS: Foram realizadas 16 gastrectomias totais, 7 subtotais, 5 laparotomias exploradoras e 2 videolaparoscopias. Para a categoria T a ecoendoscopia acertou em 25/30 casos (83,3%). Todos os restantes 16,7% foram superestimados. A precisão variou de 90% a 96,7%, de acordo com as subdivisões T1 a T4. Para a categoria N, a ecoendoscopia foi correta em 23/30 casos (76,7%), sendo 16,6% subestimados e 6,7% superestimados. A precisão variou de 76,7% a 90%, de acordo com as subdivisões N0 a N2. CONCLUSÃO: Houve nítida correlação entre a ecoendoscopia pré-operatória e os achados cirúrgicos e/ou histopatológicos em pacientes com adenocarcinoma gástrico.

Gastric cancer by multidetector row CT: preoperative staging

The role of computed tomography (CT) in the preoperative staging of gastric cancer, even if controversial, may be fundamental for evaluating the local extent and nodal involvement of the disease, especially in locally advanced cases. However, previous results of CT staging have not been satisfactory for predicting the invasive depth of the tumor or possible nodal metastases. Recently introduced multidetector row CT (MDCT) and three-dimensional (3D) imaging are expected to overcome the limitations in cancer staging by offering rapid and accurate information for space perception, detailed hemodynamics, and real-time 3D processing of volumetric data sets. In particular, virtual endoscopic imaging may be helpful for detecting early gastric cancer. In our experience, T and N stagings of gastric cancer were improved with 3D MDCT when using volume rendering and virtual endoscopic imaging compared with conventional axial two-dimensional (2D) CT (accuracy of T staging with 3D vs. 2D CT images, 84% vs. 77%; accuracy of N staging, 63% vs. 61% with 3D vs. 2D images, respectively). In particular, the detection rate of early gastric cancer was markedly increased up to 96% when using 3D MDCT. Therefore, we believe that 3D MDCT of the stomach may enhance the performance of CT in the preoperative evaluation of patients who have gastric cancer by offering easy early detection of lesions and accurate tumor staging through the 3D imaging process.

Clinical value of multidetector row computed tomography in detecting lymph node metastasis of early gastric cancer

AIMS

To evaluate the clinical value of multidetector row computed tomography (MDCT) as a pre-operative staging tool for lymph node metastasis in patients with early gastric cancer (EGC).

METHODS

In 278 consecutive patients with EGC, lymph node metastasis was evaluated pre-operatively with MDCT at a slice thickness of 2.5mm (n=57), 5.0mm (n=188), or 7.5mm (n=33).

RESULTS

Overall accuracy of nodal category from N0 to N3 was 86% for MDCT and 95% for operative assessment. Regarding accuracy in detecting at least one metastatic lymph node, area under curves (AUC) of receiver operating characteristics for 2.5, 5.0, and 7.5-mm slices and assessment during surgery were 0.87, 0.67 and 0.47, and 0.70, which were significantly different (P<0.0001). MDCT image with 2.5-mm could discriminate the presence of lymph node metastasis with diagnostic accuracy: sensitivity 80%; specificity 92%; positive predictive value (PPV) 50%; negative predictive value (NPV) 98%, whereas assessment during surgery was as follows: sensitivity 65%; specificity 98%; PPV 72%; and NPV 97%.

CONCLUSIONS

These results suggest that pre-operative assessment with MDCT using thinner slices may detect at least one lymph node metastasis as accurately as assessment during surgery for patients with EGC.

Evaluation of Siewert classification in gastro-esophageal junction adenocarcinoma: What is the role of endoscopic ultrasonography?

BACKGROUND

Preoperative assessment of gastro-esophageal junction (GEJ) adenocarcinoma stage and its location according to Siewert are essential for planning the therapeutic approach. The present study was aimed at analyzing the utility of endoscopic ultrasonography (EUS) in evaluating GEJ adenocarcinoma stage and whether this modality added to EGD improves assessment of Siewert type.

METHODS

The results of 51 patients studied by EGD plus EUS (EGD/EUS group) were compared with the results of 54 patients studied by EGD only (EGD group).

RESULTS

A differentiation of pT1 tumors was attempted by measurement of the tumor length using 4 cm as a criterion. This goal was not achieved because of a high rate of advanced tumors less than 4 cm (sensitivity and specificity were 81.3% and 34.2%, respectively). Conversely EUS ability in pT1 assessment was very reliable (92%). The accuracy in defining the Siewert type was 72.5% and 64.8% for EGD/EUS and EGD groups, respectively (P = 0.394). Some difficulties in distinguishing between type II and III tumors were observed in both groups with an extremely low specificity (44%) in classifying type II tumors by EGD group.

CONCLUSIONS

EUS seems to be essential in differentiating pT1 from advanced tumors. It shows an accuracy in defining the Siewert type of 72.5%, with some difficulties in distinguishing from type II and III tumors.

Endoscopic ultrasound for luminal malignancies

Luminal gastrointestinal (GI) tract cancers are responsible for substantial morbidity and mortality. Since the first pairing of ultrasonography with endoscopy in 1980, technologic advances and the increased availability of trained endosonographers have propelled endoscopic ultrasonography (EUS) to the forefront of luminal GI cancer staging. In this article we discuss the role of EUS for evaluating luminal GI cancers.

Transabdominal ultrasonography in preoperative staging of gastric cancer

AIM: To investigate the value of transabdominal ultrasonography (US) in the preoperative staging of gastric cancer.

METHODS: A total of 198 patients with gastric cancer underwent preoperatively transabdominal US, depth of tumor infiltration was assessed in 125 patients, and lymph node metastasis was assessed in 106 patients.

RESULTS: The staging accuracy of transabdominal US was 55.6%, 75.0%, 87.3% and 71.1% in T1, T2, T3 and T4 carcinomas, respectively. The overall accuracy was 77.6%. The detection rate for pancreatic invasion and liver invasion was 77.4%, 71.4%, respectively. The sensitivity, specificity, accuracy of transabdominal US in assessment of lymph node metastasis were 77.6%, 64.1%, 72.6%, respectively. Various shapes such as round, ovoid, spindle were encountered in benign and malignant lymph nodes. Majority of both benign and malignant lymph nodes were hyperechoic and had a distinct border. Benign lymph nodes were smaller than malignant lymph nodes in length and width (P = 0.000, 0.005). Irregular shape, fusional shape, infiltrative signs, inhomogenous echo were seen mainly in malignant lymph nodes (P = 0.045, 0.006, 0.027, 0.006).

CONCLUSION: Transabdominal US is useful for preoperative staging in gastric cancer, although it is difficult to differentiate benign from malignant lymph nodes.

Prognostic value of age and sex in early gastric cancer

BACKGROUND

The need for lymph node dissection in early gastric cancer (EGC) is controversial. The present study investigated the possibility of planning treatment for EGC according to age and sex rather than node status.

METHODS

Overall survival rate and cause of death were analysed according to age (5-year increments) and sex in 4231 patients with EGC. Cox proportional hazard regression analyses were used to identify the most valuable predictor.

RESULTS

In patients with EGC 5- and 10-year cancer-specific survival rates were 98.4 and 96.3 per cent respectively, whereas corresponding overall survival rates were 90.2 and 80.9 per cent. The critical age for determining prognosis was 70 years for men (chi2 = 131.34, P < 0.001) and 75 years for women (chi2 = 64.35, P < 0.001). For both sexes, the 10-year overall survival rate was less than 30 per cent in patients over 80 years old. Multivariate Cox stepwise regression analysis identified age as the most powerful prognostic indicator in EGC. The rate of death from causes unrelated to the tumour increased significantly with age, whereas that from recurrence was not affected by age.

CONCLUSION

Age is a better prognostic indicator than node status in both men and women with EGC. Age and sex should be taken into account as well as conventional clinicopathological variables related to lymph node metastases when determining appropriate therapy for EGC.

A prospective evaluation of catheter probe EUS for the detection of ascites in patients with gastric carcinoma

BACKGROUND

Gastric carcinoma is known for its propensity to spread to the peritoneum. This study assessed the value of EUS in the detection of ascites not visible on CT in patients with gastric carcinoma.

METHODS

A total of 402 consecutive patients with histopathologically confirmed gastric adenocarcinoma underwent catheter-probe EUS. The accuracy of catheter-probe EUS in the detection of ascites was compared with subsequent findings at laparoscopy or laparotomy.

RESULTS

There was a slight predominance of men in the study population (M:F=1.6:1). Mean patient age was 65.4+/-0.7 years. Ascites was noted by catheter-probe EUS in 36 patients (9.0%). There was no procedure-related morbidity or mortality. Ascites and peritoneal seeding subsequently were found in, respectively, 56 (13.9%) and 66 (16.4%) patients. The finding of ascites by EUS was significantly related to the presence of peritoneal seeding (p<0.001). The sensitivity, specificity, and positive and negative predictive values of EUS in the detection of ascites were, respectively, 60.7%, 99.4%, 94.4%, and 94.0%. The positive and negative likelihood ratios were, respectively, 105.0: 95% CI[26, 425] and 0.40: 95% CI[0.29, 0.55].

CONCLUSIONS

EUS is useful for the detection of ascites in patients with gastric carcinoma.

In vitro investigation of detectability of colorectal lymph nodes and diagnosis of lymph node metastasis in colorectal cancer using B-mode sonography

PURPOSE

The aim of this in vitro study was to assess the feasibility of using high-frequency sonography to identify colorectal lymph nodes and to diagnose colorectal lymph node metastasis.

METHODS

In part 1 of this study, resected colorectal tissues from 13 patients with colorectal cancer were scanned in a water bath using B-mode sonography performed at high frequency (10 MHz) to identify lymph nodes. The colorectal tissues were then carefully dissected to remove all lymph nodes. Detectability was calculated as the ratio of the number of sonographically detected nodes to the total number of histopathologically confirmed nodes. Student's t test was performed to compare sizes between these groups; a p value of less than 0.05 was considered significant. In part 2, 4 features of lymph nodes identified on B-mode sonography--size, shape, border, and echogenicity--and their combinations were evaluated for their ability to diagnose lymph node metastasis. Discriminant and receiver operating characteristic curve analyses were performed.

RESULTS

In part 1, B-mode sonography performed in vitro detected 79 (48%) of the 165 histopathologically identified lymph nodes and 34 (87%) of the 39 histopathologically identified metastatic nodes. The mean size, or mean longest axis (+/- standard deviation), of the sonographically detected nodes (6.4 +/- 2.9 mm) was significantly larger than that of undetected nodes (3.6 +/- 1.7 mm; p < 0.01). In part 2, the most effective feature distinguishing metastatic from nonmetastatic lymph nodes was echogenicity, followed by size, shape, and border. However, a combination of at least 2 features (eg, echogenicity and size) provided better distinction of nodes than did any 1 feature. In the receiver operating characteristic curve of the 4-feature combination, an increase in sensitivity is accompanied by a decrease in specificity: at a sensitivity of 100%, specificities decreased to 60% or less. However, even with the optimal combination of features, the sensitivity and specificity did not both reach 85% at any operating point.

CONCLUSIONS

The results of this node-by-node in vitro study show the current limitations and potential of sonography for assessing colorectal lymph nodes. High-frequency sonography may be insufficient for identifying lymph node metastasis in colorectal cancer.

Computer-assisted analysis of lymph nodes detected by EUS in patients with esophageal carcinoma

BACKGROUND

EUS determination of lymph nodal spread of intestinal cancer based on imaging alone is problematic. A noninvasive, reliable means of determining tumor spread to lymph nodes is desirable. This study investigated the feasibility of a computer-assisted evaluation of lymph nodes detected by EUS in patients with esophageal carcinoma.

METHODS

Images were obtained during EUS of esophageal lesions and correlated with histopathologic findings after esophagectomy. Sonographic features of echogenicity, whole-node heterogeneity, and regional variability were assessed by computerized image analysis in patients with benign versus malignant lymphadenopathy.

RESULTS

Malignant lymph nodes were hypoechoic compared with benign lymph nodes (p < 0.04). Whole lymph node heterogeneity was increased in malignant lymph nodes (p < 0.004). Regional variability was greater for benign lymph nodes.

CONCLUSIONS

These data support the feasibility of a computer-assisted system for analysis of lymph node metastasis in patients with esophageal carcinoma. Further refinements of such a system could increase the accuracy of EUS staging of tumors.

Preoperative staging of gastric cancer by endoscopic ultrasound: the prognostic usefulness of ascites detected by endoscopic ultrasound

BACKGROUND

Endoscopic ultrasound (EUS) is the standard modality in local preoperative staging of gastric cancers and is reputedly able to detect ascites. However, the association between ascites detected by EUS and local tumor staging, peritoneal carcinomatosis, or survival after surgery is not well documented.

GOALS

To assess the accuracy, sensitivity, and specificity of EUS in the preoperative staging and detection of ascites in gastric cancers. We also try to correlate ascites with histologic staging, tumor differentiation, and survival rate of gastric carcinoma after surgery.

STUDY

The retrospective analysis was made in 57 consecutive patients with histologically confirmed gastric adenocarcinomas that underwent EUS before surgery. The accuracy of EUS was compared with the final surgical-pathologic findings. We estimated the prognostic usefulness by analyzing the clinicopathologic features of gastric adenocarcinomas and following up their survival rates.

RESULTS

The overall T staging was 88% accurate by EUS. The accuracy for T staging was as follows: T1, 100%; T2, 33%; T3, 93%; and T4, 100%. About 50% of T2 cases were overstaged. The overall accuracy, sensitivity, and specificity of detecting lymph node metastasis by EUS were 79%, 79%, and 80%, respectively. One of the seven T1 cancers had regional lymph node metastasis, and it was missed by EUS, although the T classification was precisely staged based on finding submucosal invasion. A total of 22 patients (39%) had ascites detected by EUS; both the sensitivity and specificity of EUS in demonstrating ascites were 100% in our study. Ascites was significantly correlated with the depth of tumor invasion ( = 0.036), lymph node metastasis ( = 0.008), and poor cellular differentiation ( = 0.007), but it was not significantly correlated with macroscopic peritoneal carcinomatosis. The survival rate after surgical treatment was poor in those with gastric cancers with lymph node metastasis, ascites, or poorly differentiated tumors ( < 0.05). However, multivariate analysis showed that lymph node metastasis was the only significant prognostic predictor ( = 0.004).

CONCLUSIONS

Endoscopic ultrasound is a valuable diagnostic tool in the local staging of gastric cancers and demonstration of ascites. Although the surgical treatment of gastric cancers with lymph node metastasis, ascites, or poor differentiation had poorer survival rate, only lymph node metastasis was proved to be a significant prognostic predictor in multivariate analysis.

Transit endoscopic ultrasound of colorectal cancer using a 12 MHz catheter probe

The objective of this study was to examine the accuracy of a 12 MHz ultrasound catheter probe in the pre-operative staging of colorectal cancer by assessing the depth of tumour infiltration and involvement of pericolonic lymph nodes. 159 patients with colorectal cancer who underwent ultrasound examination with a 12 MHz catheter probe were studied prospectively. The results of this imaging procedure were compared with the histological findings of the resected specimens. The accuracy of the 12 MHz ultrasound catheter probe for depth of invasion (T category) was 85% (131/154) for all tumours, 87% (46/53) for pT1 tumours, 60% (9/15) for pT2 tumours, 89% (74/83) for pT3 tumours and 67% (2/3) for pT4 tumours. The accuracy for tumours of the rectum and colon was 81% and 89%, respectively. The accuracy of the probe for nodal staging (N category) was 67% (76/114) overall. The sensitivity was 70% (33/47), the specificity 64% (43/67), the positive predictive value 58% (33/57) and the negative predictive value 75% (43/57). Endoscopic ultrasound using a 12 MHz catheter probe accurately assessed tumour stage, although nodal staging remained suboptimal. This method may aid in the selection of treatment for patients with colorectal cancer.

Intraoperative US staging of T in gastric cancer: final results of a blind prospective study

BACKGROUND

In order to improve the accuracy in the assessment of depth of tumor invasion, we performed an ultrasound examination of the resected specimen intraoperatively just after removal by the surgeon (Intraoperative Ultrasonography (IUS). This prospective blind study reports the results obtained with the IUS in the staging of T in a group of 281 patients who underwent curative gastrectomy for gastric cancer.

METHODS

After the removal by the surgeon, the portion of the stomach harboring the tumor was submitted to ultrasonography with a linear 7.5 Mhz probe. An echo-free standoff pad was placed between the probe and the organ; a second echo-free standoff pad was interposed between the stomach and the support surface. The diagnosis of depth of invasion was based on the degree of disruption of the five-layer sonographic structure of the gastric wall.

RESULTS

The IUS staging of T corresponded to the pathological diagnosis in 256 out of 281 cases (overall accuracy 91.1%). The sensitivity in the different classes of T was, respectively, 91.2 in T1m cases, 83.3 in the T1sm cases, 89.6 in the T2 cases, and 93.5% in the T3 cases.

CONCLUSION

The IUS on the resected specimen has a high degree of accuracy in the assessment of depth of tumor invasion and seems to be an important advance in the clinical staging of gastric cancer.

Preoperative staging of rectal cancer using a 7.5 MHz front-loading US probe

BACKGROUND

Conventional echoendoscopes have disadvantages when used for staging colorectal cancer including the inability to pass the instrument through tight stenosis and limited maneuverability. This study evaluated the preoperative use of a newly developed 7.5 MHz front-loading ultrasound probe (FLUP) for local staging of rectal cancer.

METHODS

A 7.5 MHz FLUP, diameter 7.3 mm, was used in this study. The mechanical shaft portion of the probe can be passed in retrograde fashion through the accessory channel of a standard colonoscope. Thirty-nine patients with rectal cancer underwent ultrasonography with this probe. The tumors were staged using the TNM system, and the results were compared with the histologic findings of the resected specimens.

RESULTS

The FLUP proved to be satisfactory, with respect to maneuverability, for traversing stenosis and accurate recognition of small tumors under direct endoscopic control. The accuracy of the FLUP for T staging was 82% (32 of 39) for all tumors, 90% in pT1, and 79% in pT2 to pT4 tumors. The accuracy of the FLUP for N staging was 72% (23 of 32) overall. The sensitivity was 83%, the specificity was 65%, the positive predictive value was 59%, and the negative predictive value was 87%.

CONCLUSIONS

The 7.5 MHz FLUP appears to be useful for preoperative local staging of rectal cancer. This system makes it technically easier to image small cancers as well as advanced rectal cancers.

Experience of endoscopic ultrasound in staging adenocarcinoma of the cardia

AIM

The introduction of endoscopic ultrasonography (EUS) has generally resulted in a more accurate assessment of gastrointestinal regional tumour stage. Knowing the stage and the extent of oesophageal involvement is extremely important as a guide to the choice of surgical approach in cardia cancer. The aim of this study was to evaluate the ability of EUS to accurately predict depth of tumour invasion (T), node involvement (N) and the tumour's invasion length along the oesophagus.

MATERIAL AND METHODS

Thirty-five patients with adenocarcinoma of the cardia were studied by EUS and the EUS pre-operative findings were compared with the pathology findings.

RESULTS

The overall accuracy in T staging was 55.2% (16/29 cases). The sensitivity in evaluating T1, T2 and T3 classes was 80%, 38.5% and 70%, respectively. The sensitivity was excellent in evaluating N0 class (100%) (5 cases), but it fell to 66.7% in N1 cases. EUS correctly determined the extent of oesophagus invasion in 75.9% (22/29) of cases; moreover, it had a very high accuracy in distinguishing between tumours with an oesophageal invasion greater or lower than 2 cm (93.1%) (27/29 cases).

CONCLUSION

EUS proved to be useful in pre-operative staging of cardia adenocarcinoma and, in particular, in the pre-operative identification of the extent of oesophageal invasion.

High-resolution endoluminal sonography in gastroenterology

Endosonography is an imaging method where a high frequency ultrasound probe is inserted blindly or under endoscopic control into a lumen. Examination of the gastrointestinal tract is performed using dedicated echoendoscopes or transendoscopic miniprobes. The gastrointestinal wall, mediastinum, pancreas, bile ducts, retroperitoneum, and other structures surrounding the gastrointestinal tract are target organs for endosonography. A detailed image of pathological processes can thus be obtained. The method can be used both for primary diagnosis of lesions and in follow-up of gastrointestinal diseases. It is accurate in local staging of cancer and in detecting small lesions, which cannot be seen with other imaging modalities. There are some limitations for optimal examination like stenoses or other factors prohibiting a precise position of the ultrasound transducer. The clinical importance of endosonographic examinations must be continuously evaluated on the basis of new technical modalities and changes in therapeutic procedures.

Imaging diagnosis for staging of gastric cancer

A more differentiated therapy regimen concept for gastric cancer requires more precise pre-operative diagnostic imaging. There are several methods for pre-operative locoregional tumor staging in gastric cancer: percutaneous abdominal ultrasound with hydrotechnique (HUS), endoluminal ultrasound in the stomach (EUS), computed tomography (CT), and magnetic resonance imaging (MRI). The advantages and indications for each method are described and an overview of the medical literature is given. The results in the literature are compared to our own findings, which were obtained in prospective studies comparing the four different imaging methods. On the basis of our experience and the literature, we conclude that the indication for the different diagnostic imaging methods primarily depends on the type of therapy concept followed in the respective surgical department. Endoscopy with biopsy remains the primary diagnostic procedure. Endosonography (EUS) is another diagnostic procedure, which can be performed simultaneously with endoscopy. Only special questions or reasons warrant the use of other imaging methods.

Gastric carcinoma confined to the muscularis propria: how can we detect, evaluate, and cure intermediate-stage carcinoma of the stomach?

OBJECTIVE

The most important surgical strategy for advanced gastric cancer is its detection at the curative stage. The aim of this study was to characterize the curable intermediate-stage gastric carcinomas.

METHODS

Of 1120 consecutive patients who underwent gastric resection for primary gastric cancer from 1979 through 1996, 94 patients were histologically diagnosed as having cancer confined to the muscularis propria (mp cancer), analyzed clinicopathologically, and compared with patients with early and serosal cancers.

RESULTS

The operative incidence of mp cancer was around 8% among cases of gastrectomy, and the ratio of mp cancer to advanced cancer began to increase in 1991. Mp cancer was at a statistically intermediate stage, between early and serosal cancers in terms of symptoms, surgical curability (96%), size and histology of the tumor, and the rate of lymph node metastasis (46%). Preoperative assessments of tumor depth were unclear using radiology and endoscopy; however, 35% of 31 cases studied were diagnosed precisely by endoscopic ultrasonography (EUS). Accuracy of lymph node metastasis diagnosis was the same (65%) by preoperative EUS and by surgeon; however, sensitivity of the surgeon's assessment was higher (69% vs 38%) and specificity of EUS was higher (83% vs 39%). The 5-yr survival rate was 85%, which was significantly better than that of serosal cancer and similar to that of early cancer. Patient outcome was not affected by lymph node metastasis or macroscopic type of tumor.

CONCLUSIONS

Mp cancer should be considered an intermediate-stage cancer. Surgery with level 2 lymph node dissection should provide a cure rate similar to that for early cancer.

Pre-operative staging of ampullary tumours by endoscopic ultrasound

Ampullary carcinomas have a significantly higher resectability rate and better prognosis than other periampullary carcinomas, although the prognosis is poor with advanced disease. Accurate tumour staging is therefore important in surgical planning. Our objective was to evaluate the usefulness of, and problems associated with, endoscopic ultrasound (EUS) in the pre-operative staging of ampullary tumours. 35 patients with ampullary tumours were pre-operatively examined with EUS. The imaging results were compared with histopathological findings of the resected specimen according to the TNM staging classification. The overall accuracy of tumour (T) staging was 74% (26/35) for all tumours, and 67% (6/9), 71% (10/14) and 83% (10/12) respectively for T1, T2 and T3 tumours. The overall accuracy of nodal (N) staging was 63%. In diagnosing pancreatic invasion, EUS had an accuracy of 86% (30/35), a sensitivity of 83% (10/12), and a specificity of 87% (20/23). In conclusion, EUS provides an accurate method of evaluating the stage of ampullary tumours, especially infiltration into the pancreas. This modality is useful to surgeons in deciding on an appropriate therapeutic approach and in giving a prognosis.

Pretreatment staging of endoscopically early gastric cancer with a 15 MHz ultrasound catheter probe

BACKGROUND

The usefulness of and problems associated with an ultrasound catheter probe in the pretreatment staging of endoscopically early gastric cancer remain unexplored.

METHODS

Endoscopic ultrasonography using a 15 MHz catheter probe of 2.6 mm diameter was performed in a prospective study to determine the pretherapy staging of endoscopically early gastric cancer in 78 patients. The results of the ultrasound images were compared with the histologic findings of the specimens obtained by endoscopic mucosal resection or surgical resection.

RESULTS

The accuracy of the catheter probe for depth of invasion of endoscopically early gastric cancers was 67% (52 of 78 patients). The accuracy in determining depth of invasion in relation to endoscopic type was significantly higher for the elevated type (91%) than for the depressed type of early cancer (56%) (p < 0.01). The staging accuracy classified by histologic type was significantly higher for differentiated (86%) than for undifferentiated (18%) cancer (p < 0.01). Staging accuracy decreased as tumor size increased. The accuracy, sensitivity, and specificity for nodal staging were 80%, 17%, and 90%, respectively.

CONCLUSIONS

A 15 MHz ultrasound catheter probe is most useful for determining depth of invasion when the tumor is histologically differentiated and endoscopically of the small elevated type early gastric cancer, but it is unreliable in the diagnosis of metastatic lymph nodes.

Oesophageal cancer staging using endoscopic ultrasonography

BACKGROUND

Despite encouraging results from Europe and the USA, endoscopic ultrasonography has yet to become established in the UK for imaging gastrointestinal lesions. The aim of this prospective study was to investigate the accuracy of endoscopic ultrasonography for local tumour (T) and lymph node (N) staging of oesophageal cancer.

METHODS

Endoscopic ultrasonography was performed in 50 consecutive patients with operable oesophageal cancer. Its accuracy for locoregional tumour staging was assessed and a detailed analysis of the distribution of ultrasonographically detected lymph nodes performed.

RESULTS

Endoscopic ultrasonography was highly accurate for both local tumour (92 per cent correct T stage prediction) and lymph node (86 per cent correct N stage prediction) staging compared with final histology. The procedure was also superior to open surgical staging performed by the surgeon; it had a tendency to overestimate malignant involvement of individual lymph nodes and had only limited ability to identify small benign lymph nodes, particularly in the abdomen.

CONCLUSION

Endoscopic ultrasonography was reliable for both local tumour and lymph node staging of oesophageal cancer.

Diagnosis and staging of pancreatic cancer by endoscopic ultrasound

The aim of this study was to evaluate the usefulness of and problems associated with endoscopic ultrasonography (EUS) in the diagnosis and pre-operative staging of pancreatic cancer. 96 patients suspected of having pancreatic cancer were pre-operatively examined with EUS. 37 of these 96 patients had pancreatic cancer. Results of the EUS imaging were compared with findings of histology and/or surgery, and the patient's clinical course. The sensitivity and specificity of EUS for diagnosing pancreatic cancer were 89% and 97%, respectively. EUS had excellent sensitivity regardless of tumour size or location. EUS was accurate (90%) in determining tumour size in pancreatic cancers less than 3 cm in maximum diameter, but not for tumours greater than 3 cm (30%). The accuracy of tumour (T) and nodal (N) staging were 64% and 50%, respectively. EUS is a promising method for the early diagnosis and pre-operative staging of pancreatic cancers, but requires further refinement.

Relationship between histological type and endosonographic detection of regional lymph node metastases in gastric cancer

The aim of the study was to compare the ability of endoscopic ultrasonography (EUS) in detecting lymph node metastases in differentiated and undifferentiated gastric adenocarcinoma. EUS was performed in 149 patients with differentiated or undifferentiated gastric cancer. Histopathological findings were compared with pre-operative EUS findings in a total of 2961 resected lymph nodes. The EUS detection rates of metastasis to individual nodes in relation to node size, the ratio of the metastasized area to the cross-sectional area of the node and to the depth of primary tumour invasion, were also investigated. The accuracy and negative predictive values of EUS for detecting metastatic lymphadenopathy in each patient were significantly higher for differentiated (87%, 94%) than for undifferentiated (71%, 71%) tumours. The detection rate of individual node metastasis was higher for differentiated (31%) than for undifferentiated (21%) tumours. For differentiated lesions, EUS detected more small nodal metastases (< 5 mm in diameter) (p < 0.01) and more nodes involved with a relatively small proportion of the metastasized area to the cross-sectional area of the node (< 1/3 involvement) (p < 0.05). In relatively superficial lesions, such as pT1 and pT2, the pre-operative EUS detection rate of metastatic nodes was higher for differentiated than for undifferentiated tumours. In conclusion, the ability of EUS to detect nodal metastases is related to the histological type of gastric cancer.

Pre-operative TN staging of gastric cancer using a 15 MHz ultrasound miniprobe

The aim of the study was to evaluate the usefulness of and problems associated with a new endoscopically guided ultrasound miniprobe, used for pre-operative staging of gastric cancers. 59 cases of gastric cancer were prospectively examined with a 15 MHz ultrasound miniprobe. The results of the ultrasound imaging were compared with the histological findings of the resected specimens. The accuracy of the miniprobe for depth of invasion (T category) was 61% for all tumours, and 72% and 40%, respectively, for T1 and T2 to T4 lesions. If indeterminate cases due to ultrasound attenuation were excluded, the accuracy was improved to 82% for T1 and 57% for T2 to T4 tumours, respectively. The accuracy of the miniprobe for nodal staging (N category) was 69% overall, and 86%, 25% and 14% for stages N0, N1 and N2, respectively. In tumours classified on the basis of endoscopic types, the miniprobe staged early type gastric cancers (T category = 73%, N category = 80%) significantly (p < 0.01) more accurately than advanced ones (T category = 21%, N category = 36%). This study suggests that the miniprobe is indicated for pre-operative TN staging when endoscopy reveals an early gastric cancer.

A comparison of the accuracy of echo features during endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration for diagnosis of malignant lymph node invasion

BACKGROUND

The purpose of this study was to re-evaluate echo features of lymph nodes during endoscopic ultrasound and assess the utility of these echo features and endoscopic ultrasound-guided fine-needle aspiration in predicting malignant lymph node invasion.

METHODS

Thirty-five lymph nodes in 25 patients with lung, esophageal, and pancreatic cancer were evaluated by endoscopic ultrasound. Endoscopic ultrasound examinations were performed with a radial scanning echoendoscope. Confirmation of benign lymph nodes was obtained by surgical resection while malignant lymph nodes were confirmed by real-time endoscopic ultrasound-guided fine-needle aspiration with a linear array echoendoscope.

RESULTS

Nineteen benign lymph nodes and 16 malignant lymph nodes in the mediastinum, celiac axis, and the peripancreatic area were included in the study. The following echo features were compared between benign and malignant lymph nodes: size greater than 1 cm, hypoechoic, distinct margins, and round shape. No single feature independently predicted malignant invasion. When all four of the above features were present in the same lymph node, the accuracy for predicting malignant invasion was 80%. However, all four features of malignant involvement were present in only 25% (4 of 16) of malignant lymph nodes. Our study also suggests that the above echo features may be a less reliable predictor of malignant invasion in pulmonary malignancies when compared to gastrointestinal cancers. Endoscopic ultrasound-guided fine-needle aspiration of lymph nodes in 22 patients revealed malignant lymph node invasion in 16 and benign cells in 6 patients.

CONCLUSION

Endoscopic ultrasound-guided fine-needle aspiration is an important adjunct for accurate lymph node assessment for malignancy.

Percutaneous transhepatic intraductal biliary sonography for lymph node staging at 12.5 MHz in malignant bile duct obstruction: work in progress

PURPOSE

To assess the value of intraductal ultrasound (US) for lymph node staging in malignant biliary obstruction.

METHODS

Eighteen patients with malignant extrahepatic obstruction were imaged during percutaneous bile duct drainage with a mechanically rotating US transducer at 12.5 MHz. Detectable lymph nodes were classified as malignant when two of three criteria (hypoechoic, rounded, conspicuous margins) were fulfilled. The results were compared with histopathological data in 8 patients and follow-up CT findings in 10 patients.

RESULTS

In 15 of 18 patients (83%) malignant lymph node involvement was suspected at intraductal US and in 5 of 18 patients (28%) during CT. Histopathological investigation after operation (n = 8) and follow-up CT studies (n = 10) revealed the presence of malignant nodal involvement in 13 of 18 (72%) patients. The sensitivity, specificity, and accuracy of transhepatic intraductal biliary US in determining merely the presence or absence of malignant lymph nodes without specific topographic assignment were 92%, 40%, and 78%, respectively.

CONCLUSION

These preliminary results suggest that intraductal US may develop into a promising adjunctive modality during percutaneous bile duct drainage in patients with suspected malignant regional lymph node involvement.

MRI for staging of gastric carcinoma: first results of an experimental prospective study

PURPOSE

Our goal was to define the accuracy of MRI in the staging of gastric carcinomas.

METHOD

Twenty consecutive surgical specimens were imaged immediately after gastrectomy for gastric carcinoma. Imaging was performed with a 1.0 T imaging system. T1-weighted, T2-weighted, and opposed phase images were acquired and analyzed for tumor infiltration of the gastric wall and the presence of perigastric lymph nodes. T and N stages were classified according to the International Union Against Cancer classification. Finally histopathologic staging of the specimens was compared with staging by MRI.

RESULTS

In gastric specimens, three to five layers of the gastric walls were visible. There were typical signal intensity patterns on T1-weighted, T2-weighted, and opposed phase images. Tumor diagnosis and lymph node detection were best achieved by opposed phase imaging. Nineteen of 20 (95%) carcinomas were localized by MRI; T staging accuracy was 65%. The sensitivity to detect metastatic lymph nodes was 87%, specificity 60%. N staging accuracy (nodes positive versus negative) was 80%.

CONCLUSION

High resolution MRI of gastric tumors is possible ex vivo. MRI enabled differentiation of up to five layers of the gastric wall, and therefore staging of gastric carcinomas is technically possible. However, to evaluate the exact role of MRI as a staging tool of gastric carcinomas, a correlation between MR morphology and the histologic structure of the gastric wall has to be achieved first.

Short communication: detection of early scirrhous carcinoma of the stomach by endoscopic ultrasonography

The endoscopic ultrasonography (US) characteristics of early scirrhous carcinoma of the stomach (ESS) were evaluated in four patients. ESS was defined as the presence of poorly differentiated carcinoma cells spreading through the submucosa and muscularis propria in association with a marked desmoplastic reaction without serosal invasion. ESS was characterized by localized irregular hypoechoic enlargement of the third (submucosal) and the fourth (muscularis propria) layers. The fifth (serosal) layer was normal. The third and fourth layers showed a threefold increase in thickness compared with the thickness of these layers in healthy subjects. Our results suggest that endoscopic US is useful for diagnosis of ESS.

Endoscopic ultrasonographic findings in rectal leiomyoma

A 35 year old man visiting a hospital for his annual check-up in August 1992 was found to have a large rectal tumour on digital examination. Colonoscopy revealed a bulging lesion with normal mucosa. Endoscopic biopsy showed only normal tissue. Endoscopic ultrasonography demonstrated a large hypo-echoic submucosal tumour in the fourth layer (muscularis propria) of the rectal wall. Based on this endoscopic ultrasonographic finding, we diagnosed the tumour as leiomyoma pre-operatively. The tumour was excised by a trans-sacral local excision. The histological diagnosis of the resected specimen was cellular leiomyoma.

Current endosonographic possibilities in the upper gastrointestinal tract

Almost 15 years after its introduction endosonography is an important technique in a wide range of gastrointestinal diseases. Two types of dedicated echoendoscopes are commercially available each with their own advantages. Thinner instruments with higher resolutions, that will go through a normal endoscope are currently in development. With these probes differentiation between T1 and T in situ will be possible in the near future. Characterization of 'submucosal' lesions in the upper gastrointestinal tract is a field in which ES is the most reliable technique for determining the origin of these lesions. Also submucosal vessels are easily visualized and ES is acquiring an important role in the investigation of portal hypertension. ES is the most accurate staging technique for oesophageal and gastric carcinoma as well as for gastric lymphoma. T- and N-staging results are superior to CT scanning, although ES is not very reliable in individual lymph nodes. Therefore a lot of effort is put into obtaining cytological samples from lesions outside the gastrointestinal tract. It is now possible to get cytological proof of mediastinal lymph nodes through ES-guided fine needle aspiration biopsy. It seems that low grade malignant gastric lymphomas show a typical picture on ES, which may help in selecting treatment. The future will bring us higher resolution images and three-dimensional reconstruction is already being investigated. This last technique will probably become a standard preoperative investigation in oesophageal carcinoma before the century is over.