Warthin Tumor - Histopathology

[@vinsri2368]

Looking forward to many more vedios Thanks so much

[@misterB2231]

keep uploading more ENT pathology lectures ! you're amazing sir thanks.

[@jyotiprokashhalder]

Why are the germinal centre cells less stained?

[@FilipSokol]

Germinal centres are composed of centroblasts and centrocytes. A centroblast is an activated B cell that is enlarged (12-18 micrometer) and is rapidly proliferating. During B cell development, centrocytes are formed following the cessation of centroblast proliferation. Especially centroblasts (but to the limited extent also centrocytes) have vesicular nuclei due to higher content of euchromatin. Lymphocytes outside germinal centres have typically small, dense/dark nuclei due to higher heterochromatin content. Heterochromatin has condensed chromatin structure and is inactive for transcription, while euchromatin has loose chromatin structure and active for transcription. Vesicular nuclei look lighter on HE stain. Germinal centres also contain tingible-body macrophages responsible for phagocytosis of the apoptotic cells. They are also very lightly stained on HE. You can read about somatic hypermutation, antigen presentation, B-cell development etc. to understand the whole process. Edit: Lymphocytes outside the germinal centres are also more closely packed and therefore they look darker on low magnification.

[@jyotiprokashhalder]

@@FilipSokol Thank you so much ,Greatly appreciated.