The patient went on to have a biopsy of the nasopharyngeal mass.

Histology

Multiple fragments containing a diffuse proliferation of medium-sized atypical lymphoid cells in a background of necrosis.  The atypical cells have large irregular nuclei and prominent sometimes multiple nucleoli.  There is a small strip of acutely inflamed squamous mucosa.  Numerous coccoid micro-organisms are present within necrotic debris.  

The atypical lymphoid cells are CD20, CD79a, PAX5 and MUM1 positive.  BCL2 and BCL6 are >50%.  CD3 and CD5 stain background T cells. CD10, CD30, Cyclin D1, ALK, C-Myc, EBVISH, Kappa LC and Lambda LC are negative.  CD15 expression is equivocal.  Ki67 is 90%.  

Final diagnosis: diffuse large B cell lymphoma.  Non-GCB subtype.