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Diffuse large B-cell lymphoma (DLBCL), not otherwise specified – centroblastic morphological variant

BM MGG (1000×)

Peripheral blood is practically never affected and bone marrow involvement is rather rare in this type of B-cell neoplasms. Whether bone marrow is affected or not, centroblastic variant is the most common variant in diffuse large B-cell lymphoma (DLBCL), not otherwise specified. Centroblasts are medium-sized (red arrow) to large (green arrows) lymphoid cells with oval to round nuclei containing fine chromatin. Usually, there are two to four nuclear membrane-bound nucleoli. The cytoplasm is usually scanty and moderately basophilic; in some cells, vacuolisation can also occur (yellow arrows).

BM MGG (1000×)

Tumour cells can be different in their morphology. Some of them have the appearance of blasts with fine nuclear chromatin and a high nuclear-cytoplasmic ratio (green arrows); other pathological cells (red arrows) are smaller, with more mature chromatin and hardly visible vesicular nucleoli, but still with a high nuclear-cytoplasmic ratio. In cells with well-defined nucleoli, these nucleoli are located at the periphery of nucleus.

BM MGG (1000×)

Tumour cells must be distinguished from erythroid precursors. Unlike the proerythroblast (red arrow), the centroblast (green arrow) has a different structure of chromatin, less basophilic cytoplasm and rather light nucleoli, which are located close to the nucleus outline.

BM MGG (1000×)

Bone marrow involvement can be monomorphic like in this case, where tumour cells mostly have the appearance of centroblasts (more than 90% of tumour cells). In most cases, however, the tumour is polymorphic with an admixture of of centroblasts and immunoblasts (i.e., centroblasts account for less than 90% of tumour cells).

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