42 yrs old healthy male with lymphadenopathy, noticed after 10 days (fast progression?): isolated bilateral neck (up to 10cm left). Hepatosplenomegaly absent. LDH normal. CRB elevated 63mg/l.

HISTO: Nodules with some interfollicular diffuse areas, large amount of large cells, but admixture of small lymphos and large centrocyte like cells- its not fit into DLBCL level.

IH: CD20/BCL6/MUM1/BCL2/IgM/Ig Kappa+, IgD-/+, CD21/CD23/CD10/LMO2(-). Interestingly CD23/CD21 network more disrupted, than regular (as DLBCL or MZL infiltrating follicles). Ki67 high up to 70%.

PROPOSAL: B NHL with follicle/node formation: follicular (Bcl6+ Mum1+ CD10-) vs marginal zone lymphoma with blast access (aberant Bcl6) or DLBCL with nodular pattern/ occupation of follicles?

Thank you for continous education.