View source for 18. Diffuse large B-cell lymphoma (DLBCL)

'''Staining''': HE and PAS

'''Organ''': Lymph node (not recognizable)

'''Description''':

No healthy lymph node tissue is visible. The tumor cells form no structures (like glands or nests). The cells are large and show severe atypia/pleiomorphism, almost anaplastic. The cells resemble centroblasts and are therefore said to be centroblastic in appearance or ''centroblastoid.'' There is high mitotic activity (many mitotic figures).

On PAS staining are PAS-positive inclusion bodies in the cytoplasm and nuclei visible, so called Russell bodies and Dutcher bodies, respectively. These inclusion bodies are comprised of immunoglobulin.

'''Diagnosis''': Diffuse large B-cell lymphoma.

'''Causes''':

* Primary type: mutations in
** Myc
** BCL2
** BCL6
* Secondary type: Richter transformation from CLL, MZL or FL

'''Theory''':

Necrosis is also a common histological finding in DLBCL but it can’t be seen here.
[[File:DLBCL - overview.jpg|center|thumb|Overview]]
[[File:DLBCL - middle magnification.png|center|thumb|The tumor cells form no structures. HE on the left and PAS on the right.]]
[[File:DLBCL - high magnification.png|center|thumb|Look at this]]
[[Category:Pathology 2 - Histopathology slides]]