A practical guide to reading CT coronary angiograms—How to avoid mistakes when assessing for coronary stenoses

There are now many physicians, both radiologists and cardiologists who are reporting CT coronary angiography (CTCA) scans who may not be aware that there are many pitfalls present. For the inexperienced reader a significant stenosis in a coronary artery can be easily missed or a moderate stenosis overcalled as significant. Artifacts can also be misinterpreted as representing a significant lesion. It is important that the studies are correctly interpreted, especially as the reported high negative predictive value of CTCA scans is a major strength of this imaging technique. The learning curve of reading these scans is steep and access to conventional coronary catheterisation results is essential for feedback and to improve the readers results. We have developed some rules to aid beginners avoid some of the pitfalls that can occur as these studies are not as easy to read as they may appear initially.     

Diagnostic value of galectin-3, HBME-1, cytokeratin 19, high molecular weight cytokeratin, cyclin D1 and p27(kip1) in the differential diagnosis of thyroid nodules

The distinction between benign and malignant thyroid tumors is critical for the management of patients with thyroid nodules. We applied immunohistochemical staining for galectin-3, HBME-1, cytokeratin 19 (CK19), high molecular weight cytokeratin (HMWCK), cyclin D1 and p27(kip1) in 295 thyroid lesions to determine their diagnostic accuracy. The expression of all markers was significantly associated with differentiated thyroid carcinoma (DTC).The sensitivity for the diagnosis of DTC was 94.7% with galectin-3, 91.3% with HBME-1, and 90.3% with CK19. The specificities of these markers were 95.5%, 69.7%, and 83.1%, respectively. Combining these markers, co-expression of galectin-3 and CK19 or galectin-3 and HBME-1 was seen in 93.2% of carcinomas but in none of the benign nodules. Comparing follicular variant of papillary carcinoma (FVPC) with follicular carcinoma (FC), the expression of galectin-3, CK19, and HMWCK was significantly higher in FVPC. When comparing FC with FA, the expression of galectin-3 and HBME-1 was significantly higher in FC. These results suggest that 1) galectin-3 is a useful marker in the distinction between benign and malignant thyroid tumors, 2) the combined use of HBME-1 and CK19 can increase the diagnostic accuracy, and 3) the use of CK19 and HMWCK can aid in the differential diagnosis between PC and FC.     

Epithelioid hemangioendothelioma of the liver

Epithelioid hemangioendothelioma of the liver is a rare vascular tumor with intermediate malignant potential. On imaging studies, the lesion has a solid appearance and may mimic metastatic disease. We present a case in which the morphologic features (multifocal aspect, peripheral location, and capsular retraction) and the clinical history aided in including this entity in the differential diagnosis.     

Using a driving simulator to identify older drivers at risk of traffic infringements

Objectives: To determine the internal consistency of assessment criteria measuring the simulated driving performance of older drivers and the criterion validity of the assessment protocol related to traffic infringements. Method: One hundred and twenty‐nine older drivers residing in metropolitan Perth volunteered to participate in the study. Using a driving simulator, specific driving tasks were devised to test the participants, whose performances were measured by ten assessment criteria. Logistic regression analysis was then undertaken to determine those criteria that may be related to the event of incurring at least one demerit point during the previous two years. Results: As expected, driving skill of older drivers was found to decline with age. The Cronbach alpha coefficient among the assessment criteria was 0.742. Forty six participants incurred at least one demerit point within the previous two years. Adjusting for age in the logistic regression, the functional abilities associated with traffic infringements were decision and judgement under pressure of time, confidence in driving with high speed and compliance to traffic regulation. Conclusions: For the present study sample, the identified assessment criteria measuring the simulated driving performance of older drivers were shown to be reliable, and their significant association with the event of incurring a demerit point further confirmed the criterion validity of using the laboratory‐based driving simulator to identify older drivers at risk of traffic infringements incurring demerit points.     

The Molecular Basis for the Generation of Hodgkin and Reed-Sternberg Cells in Hodgkin’s Lymphoma

Hodgkin's lymphoma (HL) is a lymphoid neoplasm with a low frequency of malignant tumor cells, known as Hodgkin and Reed-Sternberg (H-RS) cells, in a background of mixed cellular infiltrates. Despite extensive studies on H-RS cells, the molecular mechanisms of their growth and regulation have remained uncertain for a long period. Recently, constitutively activated nuclear factor-kappaB (NF-kappaB) was reported to be a unique and common characteristic of H-RS cells that prevents the cells from undergoing apoptosis. NF-kappaB triggers proliferation and provides a molecular basis for these cells' aberrant growth and cytokine gene expression. In HL pathogenesis associated with Epstein-Barr virus infection, the activation of NF-kappaB is induced by viral latent membrane protein 1 (LMP1). Coupled with recent insights into the molecular mechanisms of activation of NF-kappaB signaling in H-RS cells, this review discusses a linkage between LMP1 and HL via CD99, which has recently been reported to be down-regulated by LMP1 through the NF-kappaB signaling pathway. This down-regulation leads to the generation of cells with H-RS phenotypes related to the clinical and histologic characteristics of HL.     

Use of the JL1 epitope, which encompasses the nonglycosylation site of CD43, as a marker of immature/neoplastic Langerhans cells

Langerhans cell histiocytosis (LCH) is the collective designation for a group of proliferative disorders of antigen-presenting cells in the epidermis. Over the past several decades, the etiology of LCH has been a controversial issue, particularly with respect to the pathologic process, that is, whether it is a neoplastic or inflammatory process. Recently, it was reported that the JL1 epitope, which encompasses the nonglycosylation site of CD43, is only exposed in the precursor stages of hematopoietic cells or in neoplastic conditions. We sought to investigate the possible utility of the JL1 monoclonal antibody as a diagnostic marker of LCH. In this study, we compared the staining characteristics of antibodies against the JL1 epitope with those of langerin and CD1a, which are widely used for the diagnosis of LCH. We found substantial differences in the staining patterns of these markers. The JL1 epitope could be bound by antibodies in cases of LCH and Langerhans cell (LC) sarcoma. In non-neoplastic lesions, JL1-positive LCs were found only in dermatitis, reflecting the immaturity of LCs in inflamed skin. However, anti-langerin antibodies were able to identify any form of LC, including those in normal skin, dermatitis, dermatopathic lymphadenopathy, and LCH. On the basis of these findings, we propose that the anti-JL1 antibody is a specific marker of immaturity, a feature that is shared in neoplastic LCs, and can be useful in the diagnosis of LCH.