On a first glance I tend to agree with your diagnosis. Being an old fashioned pathologist, I would love some high power images of the H&E stained sections to appreciate the morphology.  
Is bone marrow biopsy part of the routine work-up of these lymphoma patients?

Thank you. Please find add files (I hope virtual slides are still working?). Threpines ALWAYS are performed in all staging processes as I know.

Thanks, morphology is still useful. I managed with the CD20+ on virtual slides. Considering the morphology and Ki67 activity it looks as grade 3A. Confirmation of clonality is advised for consolidation of the diagnosis.

I'm not quite sure about applying of grading, if we stay on FL in situ idea.

I am not sure either, but the high proliferation rate should be expressed somehow.

The 2008 version of the WHO classification recognizes “in situ” FL as a new entity of intrafollicular neoplasia/ “in situ” FL but does not recommend any grading system for it. I would make sure that this patient has only “in situ” FL. Although submitted images reveal a few BCL2 negative follicles, there are many follicles showing strong Bcl-2 reactivity, which in conjunction with reportedly visceral lymphadenopathy suggests more advanced disease process and a possibility of colonization of reactive follicles by synchronous FL at another site. Did the patient undergo extensive staging work up which was negative for FL or other lymphoproliferative process?  
In the original publication by P Cong et al. (Blood 2002,99:3375-3382) the term “in situ" localization of FL was used when only a few follicles within the lymph node were involved and the most of the remaining GCs within the same lymph node were Bcl2-negative. Interestingly, in the group of 23 patients analyzed in this study who presented with “in situ” FL, 5 patients were found to have synchronous FL at another site and 2 additional patients had a composite low grade B-cell lymphoma (CLL and LPL) with “in situ” FL. Likewise, in another recent series of the 13 cases with diagnosis of intrafollicular neoplasia/” in situ” follicular lymphoma reported by S. Mantes-Moreno et al. (Histopathology 2010; 56: 652-664) 4 out of 13 patients developed full-blown FL after a median of 12 months. Furthermore, the rate of association with other non-FL lymphoid neoplasia was surprisingly high, with five out of 11 cases being associated with either cHL, SMZL or DLBCL. Interestingly, the amount of infiltration of the lymph node by intrafollicular neoplasia was associated with the probability of it actually being associated with FL in the follow up and with the presence of other lymphoma subtypes. The authors propose that this association of coexistence of “in situ” FL with other low grade B cell lymphomas, may suggest that intrafollicular neoplasia may be a sign of an increased tendency to develop lymphoid malignancies due to underlying molecular abnormalities.  
Hence, these studies show that although in some cases intrafollicular neoplasia/”in situ” FL may be diagnosed as an isolated finding, after extensive staging and follow up and behave as genuine “in situ” FL a preneoplastic condition associated with FL, but not infrequently it may precede or be associated with FL or other lymphoproliferative conditions. I would suggest close clinical follow up of the patient with extensive staging to make sure that his “in situ” FL is truly an isolated finding.  

Thanx for comments. All reccomendations were done to clinicians. I dont know exact quantification criteria for FL in situ, but there we have only partial LN involvement without interfollicular spread and "kissing" follicles, despite that majority of follicles are neoplastic.