Events on 27 September 2023

The aim of this presentation is to explain the growing importance of the use of cytopathology cell blocks in the diagnostic process and how this has evolved over recent years. In the past they were used as an 'extra' to the traditional Papanicolaou and Romanowsky stains whereas now they have an essential role in providing material for ancillary testing - immunocytochemistry and molecular studies.

The variety of methods of cell block preparation will be covered and why it is important that a department choses what method, or methods, are best suited to what is required from the finished result.

The cellular pathology of clots and cell blocks

Cell blocks from Diagnostic Cytopathology (DC) samples have always had value in the diagnostic process as a complement to the traditional cytology stains – Papanicolaou and Romanowsky. It has become more important to provide material for Immunocytochemistry to refine malignant diagnosis, and more recently, the use of molecular testing to aid in the choice of tailored chemotherapy regimens. If this information can be obtained from DC samples, which are less invasive than biopsy samples, the patient will benefit.

External Quality Assurance of cell block preparations has up to now been covered by the Tissue Diagnostic scheme. However, this is not entirely appropriate as cytopathology departments use a variety of cell block preparation methods and fixatives. The increase in number of cell block Haematoxylin and Eosin slides submitted to our evaluation service and the queries we receive regarding advice on best preparation methods suggested there was a need for a separate scheme for evaluation of cell blocks. A circulated survey indicated that there is a need for such a scheme. In response to this we performed 2 pilot studies which were well supported and successful, leading to the launch of the live scheme in April 2023.

This presentation covers the development of the scheme and the results of the 2 pilots. As an ongoing process the scheme will be able to garner information about ‘best methods’ and this can be passed on to laboratories experiencing problems and improve standards. UKNEQAS CPT is not just a ‘tick box’ service for UKAS, it is also an advisory service which aims to improve diagnostic practices.

Whats new in Diagnostic Cytology (Reporting systems; biomarker testing)

vWF Guideline Update

Thrombophilia is defined as hereditary and/or acquired conditions associated with an increased predisposition to thrombosis. The previous British Society for Haematology guideline on thrombophilia testing (2012) focused only heritable thrombophilia testing. The updated guideline published in 2022 (1) has a widened scope to include both heritable and acquired thrombophilia especially antiphospholipid antibodies, paroxysmal nocturnal haemoglobinuria, myeloproliferative neoplasm (MPN) and the presence of a JAK2 mutation in the absence of an MPN phenotype. Disorders such as cancer, inflammatory conditions and obesity are associated with thrombosis through multiple mechanisms, but these are not included in the guideline which focuses only the factors identified from laboratory testing.

The key principle in the guideline is that when clinical utility of testing is not clear, thrombophilia testing is not mandatory, and testing should be done only if the result will alter the management of the patient. These guidelines emphasise the importance of identifying antiphospholipid syndrome and JAK2 +/- MPN phenotype because they have a significant impact on management. The guidelines confirm the limited utility of testing for hereditary thrombophilia testing in venous thromboembolism, arterial thrombosis and recurrent pregnancy loss.

1. Arachchillage, DJ, Mackillop, L, Chandratheva, A, Motawani, J, MacCallum, P, Laffan, M. Thrombophilia testing: A British Society for Haematology guideline. Br J Haematol. 2022; 198: 443– 458. https://doi.org/10.1111/bjh.18239

The effects of long COVID on coagulopathy

Effects of direct thrombin inhibitors [dabigatran/argatroban/bivalirudin] on tests of haemostasis

Meet your Haematology Portfolio examiners

A case study into iron deficiency polycythaemia diagnosis, looking at the pathology and how this relates to the results we see and investigations to confirm diagnosis.