Double immunohistochemistry enhances detection of lymphatic and venous invasion in early-stage colorectal cancer.

Lymphatic invasion (LI) and venous invasion (VI) are regarded as important risk factors of nodal disease in early-stage colorectal cancer (CRC) but with variable reporting and poor distinction of these parameters in previous studies. This study examines the application of a double immunohistochemistry (D-IHC) method to help detect and distinguish LI and VI, in comparison with haematoxylin and eosin (H&E) staining, in a clinical series of cases of stage pT1 CRC. The aims were to demonstrate feasibility of this methodology in routine practice and compare rates of LI and VI reporting with and without D-IHC application. D-IHC utilising CAM5.2 with the endothelial marker CD34 and with the specific lymphatic endothelial marker D2-40 was performed on parallel sections from single representative paraffin tissue blocks in 28 cases of stage pT1 CRC from routine clinical practice. D-IHC significantly increased rates of both LI and VI reporting, from 14.3 to 35.7 % and from 14.3 to 28.6 %, respectively. The D-IHC methodology described is technically feasible in routine practice and potentially offers a more sensitive and robust assay for detection and distinction of LI and VI in early CRC pathology reporting. The reproducibility and clinical significance of enhanced LI and VI detection by this method and the relative importance of LI and VI in this clinical setting require further study.

Integrating molecular diagnostics into histopathology training: the Belfast model.

Molecular medicine is transforming modern clinical practice, from diagnostics to therapeutics. Discoveries in research are being incorporated into the clinical setting with increasing rapidity. This transformation is also deeply changing the way we practise pathology. The great advances in cell and molecular biology which have accelerated our understanding of the pathogenesis of solid tumours have been embraced with variable degrees of enthusiasm by diverse medical professional specialties. While histopathologists have not been prompt to adopt molecular diagnostics to date, the need to incorporate molecular pathology into the training of future histopathologists is imperative. Our goal is to create, within an existing 5-year histopathology training curriculum, the structure for formal substantial teaching of molecular diagnostics. This specialist training has two main goals: (1) to equip future practising histopathologists with basic knowledge of molecular diagnostics and (2) to create the option for those interested in a subspecialty experience in tissue molecular diagnostics to pursue this training. It is our belief that this training will help to maintain in future the role of the pathologist at the centre of patient care as the integrator of clinical, morphological and molecular information.

Well-differentiated papillary mesothelioma: peritoneal implants are not always metastases in the presence of cancer.

INTRODUCTION: Well-differentiated papillary mesothelioma is a rare condition that can cause diagnostic uncertainty. Its appearance resembles metastatic deposits and in the presence of a known primary can often be confused for such. CASE PRESENTATION: In this case, we present a patient who had WDPM in the presence of gastric cancer and emphasise the difficulties in making the diagnosis. CONCLUSION: We highlight the need for a high index of suspicion, biopsies at staging laparoscopy and undertake a review of the literature regarding this uncommon condition.