Dear Ugnius,  
 
the cell morphology looks anaplastic to me. Those DLBCL may show a sinusoidal pattern. CD5 may be intersting.  
The very strong CD15 positivity is very peculiar. I was wondering if this is enough to call it B-cell lymphoma, unclssifiable, with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma (I guess not). All other features are for me in favor of DLCL anaplastic variant.

Dear Ugnius,  
 
please add ALK, CD138, CD79a, Cyclin E, Cyclin D1, CD2, PAX5, CD5, CD23 and p63 or any of them. Does the lady have a tumoral mass or CNS symptoms?

I agree with the diagnosis of DLBCL, anaplastic variant, intrasinusoidal. I also agree that CD5 would be of interest, I also wonder about EBV association. In a series of Lymphomas in the elderly, we have seen an unusually large proportion of intrasinusoidal DLBCL.  
Are you really sure about CD30+, I am not convinced, however there is no question about CD15+.  
 
I also remember an old case of yours of B-cell lymphoma CD15+  
(ID1652) I am copying Attilio Orazis comment of this case:  
A bit of a dilemma. I am surprized that the large cells do not express CD30. Are you sure? Overall, this case resembles cases that have been described as "Large B-cell lymphoma with Hodgkin's features" by Garcia et al in Histopathology (2005 Jul;47(1):101-10)or as T cell rich B cell lymphoma (TCRBCL) by others but with an important difference: your case shows CD15 positivity which is highly unusual in cases of TCRBCL. I cannot tell on the pics. whether the CD15 positive cells correspond to the CD20 positive one or maybe are histiocytes?

Please find your requested stains: CD5(-); ALK1(-); etc. I will repeat CD15/CD30 sequence for sure. The patientin was from breast surg dept, so clin data are scarse at the moment.

The last point: add stains was added on OTHER block. The results are the same. New stain: LCA+ 70%, EBER EBV(-). Really these large CD15+ cells are obviously neoplastic, not histiocytic, as in other cases when macrophages somtimes shows faint CD15+/-. CD30 expresion does present, but in lesser amount than CD15.

I belive the best diagnosis is most likely DLBCL. Intrasinusoidal pattern of involvement may or may not be present in other sites of involvement. Intravascular lymphoma needs to be considered. Unusual expression of CD15 and borderline CD30; however, we do not know if the lesion is BOB.1, Oct-2, and PU.1 positive or negative. I expect that CD45 should be positive. HHV8 may also be informative in an unusual case of DLBCL. It seems like that by phenotype and cytology this may qualify for B cell lymphoma, unclassifiable, with features intermediate between DLBCL and cHL, but am not sure if this pattern of growth is acceptable. I wonder if there is mediastinal mass? Correlation with clinical findings and previous history is critical. It is not clear if this is extranodal lesion secondarily involving LN or breast nodule was actually LN. If there is skin and CNS involvement, intravascular lymphoma could be favored dx. History of low-grade B cell lymphoma may help as this may be transformation event.