[Preliminary clinical experience of transrectal ultrasonography in early rectal cancer].

OBJECTIVE: To evaluate the accuracy of transrectal ultrasonography (TRUS) in the assessment of the invasion depth of rectal cancer, and analyze the value of TRUS in diagnosis of early rectal cancer. METHODS: TRUS was performed preoperatively in 163 patients with rectal cancer, and the results was compared with the postoperative pathological findings according to TNM staging. The early rectal cancer was diagnosed if the lesion was limited to mucosa and submucosa. The tumor located in mucosa was defined as mucosal cancer, while as submucosal cancer when the tumor invading into submucosa. Sixteen cases were confirmed as early cancer by pathology after the operation. No patients received chemotherapy and radiotherapy before operation. RESULTS: The sensitivity of TRUS in the staging of the early rectal cancer was 87.5% (14/16), specificity was 98.6% (145/147), and the positive predictive value was 87.5% (14/16). The sensitivity of TRUS in predicting mucosal and submucosal cancer was 85.7% (6/7) and 66.7% (6/9), respectively. Sixteen patients with early rectal cancer were examined before and after filling rectum with water. After filling rectum, all tumors were visualized clearly, while 14 tumors were correctly diagnosed as early rectal cancer. Before filling rectum, only 6 tumors were visualized clearly, and 3 tumors were staged correctly. The ultrasonographic appearance of early rectal cancer manifested in two kinds: protruded and ulcerative, and most were protruded (81.6%). CONCLUSIONS: TRUS is a valuable imaging examination for diagnosis of early rectal cancer preoperatively. Visualization rate and diagnostic accuracy of early rectal cancer are improved dramatically after filling rectum with water.

[The assessment of wall invasion of rectal carcinoma: correlation of endoluminal ultrasonographic and pathologic findings].

OBJECTIVE: To evaluate the accuracy of endoluminal ultrasonography (ELUS) in the preoperative assessment of wall invasion of rectal carcinoma and analyze its influencing factors. METHODS: ELUS was performed preoperatively in 117 patients with rectal carcinoma, in which no preoperative treatment was given. The results of ELUS were correlated with operative and pathologic findings according to the TNM classification. We observed the following factors and analyzed their impact on the accuracy of ELUS: tumor location, the depth of the tumor invasion, and the inflammatory cell infiltration and fibrosis peritumor. RESULTS: The overall accuracy of ELUS in T stage was 76.9% (90/117). The sensitivity of ELUS for pT(1), pT(2), pT(3) and pT(4) carcinoma was 87.5% (7/8), 51.7% (15/29), 85.7% (60/70), 80% (8/10), respectively. Misdiagnosis occurred in 27 cases, of which 14 cases were overstaged and 13 cases were understaged. The sensitivity for pT(2) carcinoma was the lowest; 14 cases were misdiagnosed, of them 13 cases were overstaged. Overstaging with ELUS for pT(2) carcinoma occurred mainly in these cases in which inflammatory cell infiltration, fibrosis or tumor involved more than one-third of muscularis propria. 13 cases were understaged, of which tumors in 7 cases were located in superior segment of rectum and 4 cases with obviously rectal stenosis. When tumor was located in middle or lower segment of rectum, misdiagnostic rate was 18.5% (17/92); while tumor was located in superior segment of rectum, misdiagnostic rate was 40% (10/25), and differences were statistically significant between two groups in misdiagnostic rate (P = 0.024). CONCLUSION: Although ELUS in the preoperative assessment of wall invasion of rectal carcinoma is useful, it is difficult to avoid overstaging and understaging of ELUS. The overstaging is an important unfavourable factor in assessing the invasion depth of pT(2) carcinoma with ELUS, and the depth of tumor invasion muscularis propria, and the depth of inflammatory cell infiltration and fibrosis might be responsible for overstaging. Obviously rectal stenosis and tumor being located in the superior segment of rectum might cause understaging.

[Identification the invasion range of hepatocellular carcinoma by contrast-enhanced ultrasound].

OBJECTIVE: To study the histopathologic characteristics of the enlarged enhancement area of hepatocellular carcinoma (HCC) at contrast-enhanced ultrasound (CEUS) during the arterial or portal phase and evaluate the value of CEUS in identifying the invasion range of HCC. METHODS: Fifty-two patients with fifty-two lesions confirmed as HCC pathologically (41 by surgery and 11 by needle biopsy) were included. The lesion size, margin and shape at fundamental ultrasonography (US) and CEUS were compared before surgery or needle biopsy. Lesions with a larger enhancement area and/or a more irregular shape during the arterial or portal phase at CEUS were classified as group A; lesions with unchanged size and shape were classified as group B. The tissues specimens of the tumor margin (peripheral tumor tissues) were obtained and the slides were stained with HE and CD34 immunohistochemistry, the histopathology and microvessels density (MVD) of group A and B were compared. RESULTS: In group A, 75% (24/32 lesions) had vaguely demarcated margin at US compared with 40% (8/20 lesions) in Group B (P < 0.05). The largest average diameter of Group A was 6.1 +/- 2.9 cm compared with 4.4 +/- 2.1 cm in group B (P < 0.05). Of the 41 surgically resected HCC specimens, 88% of the 75 slides for the 25 lesions in Group A demonstrated cancer cells invasion in the peripheral tumor, much higher than the 56.3% (27/48 slides) of the 16 lesions in Group B (P < 0.001). The MVD in Group A by CD34 immunohistochemistry was significant higher than that in Group B (52.25 vs 36.82, P < 0.01). CONCLUSION: The enlarged enhancement area of HCC at CEUS correlated with the sharpness of tumor margins. The cancer cells invasion and more microvessels generation in the enlarged enhancement area reflected the histopathologic characteristics of invasive growth pattern of HCC. CEUS is helpful in identifying the actual tumor size and invasion range, and might be helpful for HCC treatment.

[Intraperitoneal hemorrhage during and after percutaneous radiofrequency ablation of hepatic tumors: reasons and management].

BACKGROUND: Intraperitoneal hemorrhage is one of the most common complications of radiofrequency (RF) ablation of hepatic tumors. This study was designed to investigate the reason and management of intraperitoneal hemorrhage occurred during or after percutaneous RF ablation of hepatic tumors. METHODS: Three hundred and fifty-six patients with hepatic tumors have been treated at 592 procedures of ultrasound guided RF ablation. Intraperitoneal hemorrhage occurred in 5 patients (0.8%). The reasons and management of intraperitoneal hemorrhage in these 5 cases were retrospectively analyzed. RESULTS: Two patients with liver metastasis and one hepatocellular carcinoma (HCC) patient suffered from hemorrhage during the RF treatment. Two patients with recurrent HCC after surgery developed hemorrhage 20 minutes or 4 hours after RF treatment. One case of hemorrhage was due to the inappropriate electrode positioning induced liver laceration while treating a 1 cm liver metastasis near the liver capsule. One was due to the injury of a small vessel by the RF needle in another liver metastasis patient. Three cases were due to tumor rupture with two cases induced by cough or position change after treating large protruding HCC lesions. Four (80%) of the 5 cases of hemorrhage were rapidly identified by ultrasound. The causes and sites of bleeding during the RF treatment in three cases were confirmed through ultrasound, which were successfully treated using RF coagulation to achieve hemostasis of the bleeding site. Two patients with post-ablation hemorrhage recovered in one hour and 24 hours, respectively after given blood transfusion and other conservative measures. No surgical intervention was required. Two patients died of wide spread metastasis 23 - 36 months afterwards and the other three patients have lived for 18 - 25 months to date. CONCLUSIONS: It is important to perform close monitoring during and after RF ablation in order to identify intraperitoneal hemorrhage in time. RF ablation of the bleeding sites was a simple and effective management when the bleeding site could be confirmed by ultrasound. The hemorrhage due to the rupture of large and protruding liver tumors could be serious and should be considered as contraindication for RF treatment.

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.