The Role of Contrast-enhanced Ultrasound in Guiding Radiofrequency Ablation of Hepatocellular Carcinoma: A Retrospective Study.

PURPOSE: The objective of the study was to determine the efficacy of contrast-enhanced ultrasound (CEUS) using ultrasound (US)-specific microbubbles in guiding radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC). METHODS: A retrospective analysis of 50 patients with HCC treated with CEUS guided RFA using perflutren at our institution was performed. CEUS images were first compared to B-mode US images performed at the same RFA session to determine the ability of CEUS to increase the conspicuity of lesions. A qualitative score (1 = poor, 2 = fair, 3 = excellent) was used to grade the ability to visualize the lesions. The preprocedure CEUS images were then evaluated using the most recent prior contrast enhanced computed tomography (CT) or magnetic resonance imaging (MRI). The efficacy of the treatment was evaluated with short-term follow-up imaging (median 1 month) for presence of residual or recurrent disease. RESULTS: CEUS allows at least fair visualization (score ≥2) in 78% (reader 1) and 80% (reader 2) of the lesions not visualized by B-mode US, and 50% (reader 1) and 42% (reader 2) of the lesions poorly visualized by B-mode US. Lesion appearances on CEUS are largely concordant with those on CT or MRI: 88% for reader 1, 96% for reader 2. With CEUS-guided RFA, complete response was achieved in the vast majority of the lesions at short-term follow-up: 82% for reader 1, 94% for reader 2. CONCLUSIONS: CEUS increases the conspicuity and provides better characterization of hypervascular HCC that are either not seen or poorly seen on B-mode US, and CEUS provides real-time guidance of RFA with good short-term treatment responses.

Clinicopathologic factors and nuclear morphometry as independent prognosticators in KIT-positive gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are mesenchymal neoplasms found in the gastrointestinal tract. The purpose of this study was to evaluate whether morphometric measurements could complement tumor size and mitotic activity in risk evaluation. Nuclear roundness and ellipse axis ratio were found to correlate with tumor size, mitotic activity, nuclear atypia, and hemorrhage. Morphometric variables in 422 GISTs were significant for overall survival in univariate analyses but did not retain independent significance in multivariate analyses incorporating mitotic count and tumor size. Traditional variables, together with sex, location of primary tumor, and nuclear atypia, seem to be the best parameters for prognostic evaluation.

Nuclear beta-catenin in mesenchymal tumors.

Beta-catenin is a crucial part of the Wnt and E-cadherin signalling pathways, which are involved in tumorigenesis. Dysregulation of these pathways allow beta-catenin to accumulate and translocate to the nucleus, where it may activate oncogenes. Such nuclear accumulation can be detected by immunohistochemistry, which may be useful in diagnosis. Although the role of beta-catenin has been established in various types of carcinomas, relatively little is known about its status in mesenchymal tumors. A number of studies suggest that beta-catenin dysregulation is important in desmoid-type fibromatosis, as well as in synovial sarcoma. We wished to determine whether nuclear beta-catenin expression is specific to and sensitive for particular bone and soft-tissue tumors, including sporadic desmoid-type fibromatosis. We studied the nuclear expression of beta-catenin using tissue microarrays in a comprehensive range of bone and soft-tissue tumor types. A total of 549 cases were included in our panel. Nuclear immunohistochemical staining was determined to be either high level (>25% of cells), low level (0-25%) or none. High-level nuclear beta-catenin staining was seen in a very limited subset of tumor types, including desmoid-type fibromatosis (71% of cases), solitary fibrous tumor (40%), endometrial stromal sarcoma (40%) and synovial sarcoma (28%). Although occasional cases of fibrosarcoma, clear cell sarcoma and carcinosarcoma had high-level staining, no high-level nuclear beta-catenin expression was seen in any of 381 fibrohistocytic, muscular, adipocytic, chondroid or osseous tumor cases representing 42 diagnostic categories. All primary immunostain tissue microarray images are made publicly accessible in a searchable database. High-level nuclear beta-catenin staining serves as a useful diagnostic tool, as it is specific to a small subset of mesenchymal tumors.