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Chronic lymphocytic leukaemia – transformation to diffuse large B-cell lymphoma (DLBCL), Richter’s syndrome

BM MGG (1000×)

Some of the tumour cells are small lymphocytes with dark clumped chromatin, often with a mosaic pattern (the blocs of mature chromatin are separated from each other by light border lines); these cells have scanty cytoplasm and regular outlines (red arrows). However, cells with an appearance of blasts (green arrows) are also present in cases of this type of transformation. These large cells have less mature chromatin, a high nuclear-cytoplasmic ratio and mostly one prominent nucleolus. 

BM MGG (1000×)

Tumour cells with an appearance of blasts can be also morphologically different. These cells can have one or more nucleoli, but they generally have a high nuclear-cytoplasmic ratio and a slightly less mature chromatin than mature lymphocytes. The haemophagocytosis of an erythrocyte by the tumour cell (yellow arrow) documents the aggressive nature of the disease.

BM MGG (1000×)

Tumour cells with an appearance of blasts can be more frequent (green arrows) in some regions of bone marrow smears. This is a difference when compared to cases of diffuse large B-cell lymphoma (DLBCL), in which bone marrow involvement is rather rare. In Richter’s syndrome, mature tumour cells (red arrows) are always present, too.

BM MGG (1000×)

The presence of mastocytes (white arrow) is quite frequent in cases of chronic lymphocytic leukaemia; it can occur also in transformation cases. 

BM MPO (1000×)

Myeloperoxidase staining clearly shows the negativity of cells with an appearance of blasts (green arrows) and of small lymphocytes (red arrows), too. The positivity of a segmented neutrophil (black arrow) documents the accuracy of investigation.

Atlas of Haematological Cytology [online]. 2016 [cit. 2024-3-29]. Available from WWW: http://www.leukemia-cell.org/atlas.

2024 CELL - Atlas of Haematological Cytology | site map