This is a 58-year-old man with a history of mantle cell lymphoma, now he has a right arm mass. The FNA was done. What's your diagnosis? Are you going to do more studies?

This should be a easy case, but does bring an interesting topic to discuss: what's the role of FNA in the diagnosis of lymphoproliferative disorder?

 海上明月：You did a wonderful summary on the approach of using FNA for lymphoproliferative disorder. Basically, FNA combined with other tests (Flow, FISH, etc.) can be used to diagnose lymphoma, it is even more accurate for monitor recuurent lymphomas. But, it has its limitation, for example, some T-cell lymphomas can be very difficult or impossible on FNA.

 This case the flow cytometry of the arm mass FNA showed the exact phenotype of this patient's previous mantle cell lymphoma.