Highly atypical lymphocytes, consistent with involvement by the patient's known lymphoma.

In a case like this with matched  morphology and clear history, we don't do immunostains sometimes.  In fluids, flow cytometry is more informative than immuostains.  It can provides info about treatment choices.

In such a case, close communication with your clinician is essential.  This is the time to build your respect and relationship with clinicians and show your value in patient's care.  We usually call the doc right away.

After all this, i found this is an ancient case. HaHa!