Value of CT in the diagnosis and management of gallstone ileus

IM: To retrospectively establish the diagnostic criteria of gallstone ileus on CT, and to prospectively apply these criteria to determine the diagnostic accuracy of CT to confirm or exclude gallstone ileus in patients who presented with acute small bowel obstruction (SBO). Another purposewas to ascertain whether the size of ecctopic gallstones would affect treatment strategy.METHODS: Fourteen CT scans in cases of proved gallstone ileus were evaluated retrospectively by two radiologists for the presence or absence of previously reported CT findings to establish the diagnostic criteria. These criteria were applied in a prospective contrast enhanced CT study of 165 patients with acute SBO, which included those 14 cases of gallstone ileus. The hard copy images of 165 CT studies were reviewed by a different group of two radiologists but without previous knowledge of the patient's final diagnosis. All CT data were further analyzed to determine the diagnostic accuracy of gallstone ileus when using CT in prospective evaluation of acute SBO. The size of ectopic gallstone on CT was correlated with the clinical course.RESULTS: The diagnostic criteria of gallstone ileus on CT were established retrospectively, which included: (1) SBO; (2) ectopic gallstone; either rim-calcified or total-calcified; (3) abnormal gall bladder with complete air collection, presence of air-fluid level, or fluid accumulation with irregular wall. Prospectively, CT confirmed the diagnosis in 13 cases of gallstone ileus with these three criteria. Only one false negative case could be identified. The remaining 151 patients are true negative cases and no false positive case could be disclosed. The overall sensitivity, specificity and accuracy of CT in diagnosing gallstone ileus were 93%, 100%; and 99%, respectively. Surgical exploration was performed in 13 patients of gallstone ileus with ectopic stones sized larger than 3 cm. One patient recovered uneventfully following conservative treatment with an ectopic stone sized 2 cm in the long axis. CONCLUSION: Contrast enhanced CT imaging offered crucial evidence not only for the diagnosis of gallstone ileus but also for decision making in management strategy.

Giant malignant gastrointestinal stromal tumors: Recurrence and effects of treatment with STI-571

AIM: Malignant gastrointestinal stromal tumors (GISTs)are rare. Tumors larger than 10 cm tend to recur earlier:the larger the volume of the tumor, the worse the prognosis.We hypothesized that treatment with imatinib mesylate (Gleevec; STI-571), a c-kittyrosine kinase inhibitor, as palliative therapy would prolong the survival of patients with recurrent giant malignant GISTs after resection.METHODS: We performed a retrospective analysis of the effects of resection on patients with giant GISTs (＞10 cm in diameter) to determine the overall survival and recurrence rates. Twenty-three patients diagnosed with giant GISTs were included from June 1996 to December 2003. STI571 was not available until January 2000. After that time,9 patients received this drug. The factors of age, sex, tumor location, histological surgical margin, and STI-571, tumor size changes and drug side effects were reviewed. We compared the survival rate to determine the prognostic factors and the effects of STI-571 on patients with recurrent malignant gastrointestinal stromal tumor.RESULTS: The positive surgical margin group had a significantly higher recurrence rate than the negative margin group (P = 0.012). A negative surgical margin and palliative treatment with STI-571 were significant prognostic variables (Log-rank test,P＜0.05). Age, sex and tumor location were not significant prognostic variables. The 5-year survival rate of the surgical margin free patients was 80%and the 2-year survival rate of the surgical margin positive patients was 28%. The 5-year survival rate was 80% for the patients given STI-571 and 30% for the patients not given STI-571. The use of STI-571 gave a significant tumor shrinkage (6/9) rate in patients with giant GIST recurrence after resection.CONCLUSION: A negative surgical margin and the use of STI-571 after surgical resection were good prognostic indicators. Achieving a tumor-free surgical margin is still the best primary treatment for patients with such tumors.If STI-571 is used immediately when the surgical margin is positive and the tumor recurs after resection, then the prognosis of patients with giant GISTs can be improved.

Decreased expression of type Ⅱ tumor suppressor gene RARRES3 in tissues of hepatocellular carcinoma and cholangiocarcinoma

AIM: To analyze the expression of retinoic acid receptor responder 3 (RARRES3) protein in paraffin-embedded tissues of hepatocellular carcinoma (HCC) and cholangiocarcinoma(CC), and the correlation of RARRES3 production with tumor differentiation.METHODS: Expression of RARRES3 in tissues from 21CC (10 well-, 7 moderately- and 4 poorly-differentiated)and 32 HCC was determined by immunohistochemistry.RESULTS: Among 21 CC tissues, RARRES3 was detected in 8 (80%) of 10 well-differentiated tumors. Only 2 (18.2%)out of 11 tumors with moderate or poor differentiation showed positive RARRES3 expression. RARRES3 expression in well-differentiated CC was significantly higher than that in tumors with moderate or poor differentiation (Fisher exact test, P＜0.01). Expression of RARRES3 was not different between early (Ⅰ and Ⅱ) and late (Ⅲ and Ⅳ) stages of CC.Among 30 HCC tissues, 17 (56.7%) weakly expressed RARRES3 in HCC cells, and 25 (83.3%) normal tissues adjacent to HCC expressed the protein. RARRES3 expression was significantly decreased in HCC tissues compared to that in adjacent normal tissues (logistic regression analysis, OR = 0.27, 95% CI (0.11-0.62), P＜0.01).CONCLUSION: Expression of RARRES3 is positively correlated to well-differentiated CC, which supports the role of RARRES3 in malignant epithelial differentiation of the tumor. The decrease in RARRES3 expression in tissues of HCC and CC with moderate and poor differentiation suggests that altered RARRES3 expression may play a role in the carcinogenesis of the liver and biliary tract.