We herein present an overview of the upcoming 5thedition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4thedition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5thedition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms.
Summary: Approximately 30 000 cases of non‐Hodgkin lymphoma (NHL) occur in the equatorial belt of Africa each year. Apart from the fact that Burkitt lymphoma (BL) is very common among children and adolescents in Africa and that an epidemic of human immunodeficiency virus (HIV) infection is currently ongoing in this part of the world, very little is known about lymphomas in Africa. This review provides information regarding the current infrastructure for diagnostics in sub‐Saharan Africa. The results on the diagnostic accuracy and on the distribution of different lymphoma subsets in sub‐Saharan Africa were based on a review undertaken by a team of lymphoma experts on 159 fine needle aspirate samples and 467 histological samples during their visit to selected sub‐Saharan African centres is presented. Among children (<18 years of age), BL accounted for 82% of all NHL, and among adults, diffuse large B‐cell lymphoma accounted for 55% of all NHLs. Among adults, various lymphomas other than BL, including T‐cell lymphomas, were encountered. The review also discusses the current strategies of the International Network of Cancer Treatment and Research on improving the diagnostic standards and management of lymphoma patients and in acquiring reliable clinical and pathology data in sub‐Saharan Africa for fostering high‐quality translational research.
Studies on ER/PR/HER2 in breast cancer from Sub Saharan Africa (SSA) are fraught with inconsistencies in the prevalence of hormone receptor status. In Kenya, ER/PR/HER2 for breast cancers is not part of routine assessment and available in only three to four centers across the country. Variability in methodology and interpretation makes comparison between data difficult. Our aim was to accurately determine the prevalence of ER/PR/HER2 using standardized techniques and double reporting. Prognostic tumor parameters were also correlated with clinical features and receptor status. Consecutive invasive breast cancers (IBC) accrued between September 2011 and December 2012 were analyzed at Aga Khan University Hospital, Nairobi (AKUHN). Tumor blocks were stained for ER/PR/HER2 on an automated platform. Double reporting of ER/PR/HER2 was done using the Allred system and the ASCO/CAP guidelines respectively. A total of 301 cases of IBC were analyzed for pathology and ER/PR/HER2. The age range of patients was 19-94 years with a median of 47.5 years. Invasive ductal carcinoma (NOS) was the most common histologic type (84.2%). ER positivity was seen in 72.8%, PR in 64.8% and HER2 in 17.6% of all cases. Triple negative breast cancers (TNBC) constituted 20.2% of the cases. There was a significant association between receptor status and histologic grade (p < 0.001) and statistically significant trend of increasing pathological stage of tumor (pT) associated with TNBC (p = 0.020). We present a definitive prospective analysis of ER/PR/HER2 from a single center and demonstrate that prevalence of receptor status from SSA is comparable with that in the West.
Summary: Distinguishing Burkitt lymphoma (BL) from B cell lymphoma, unclassifiable with features intermediate between diffuse large B‐cell lymphoma (DLBCL) and BL (DLBCL/BL), and DLBCL is challenging. We propose an immunohistochemistry and fluorescent in situ hybridization (FISH) based scoring system that is employed in three phases – Phase 1 (morphology with CD10 and BCL2 immunostains), Phase 2 (CD38, CD44 and Ki‐67 immunostains) and Phase 3 (FISH on paraffin sections for MYC, BCL2, BCL6 and immunoglobulin family genes). The system was evaluated on 252 aggressive B‐cell lymphomas from Europe and from sub‐Saharan Africa. Using the algorithm, we determined a specific diagnosis of BL or not‐BL in 82%, 92% and 95% cases at Phases 1, 2 and 3, respectively. In 3·4% cases, the algorithm was not completely applicable due to technical reasons. Overall, this approach led to a specific diagnosis of BL in 122 cases and to a specific diagnosis of either DLBCL or DLBCL/BL in 94% of cases that were not diagnosed as BL. We also evaluated the scoring system on 27 cases of BL confirmed on gene expression/microRNA expression profiling. Phase 1 of our scoring system led to a diagnosis of BL in 100% of these cases.