The patient went on to have a biopsy.
Histology
Microscopic Description:
The biopsy of retroauricular mass shows skeletal muscle which is heavily infiltrated by plasma cells. While many of these are almost normal appearing, there are several extremely atypical cells with enlarged nuclei, prominent nucleoli and an increased nuclear-to-cytoplasmic ratio. The biopsy is crushed and little material was left on the immunoperoxidase slides, but these appear to show that the lesion stains for IgG kappa.
Final Diagnosis: plasmacytoma.
The patient went on to receive radiotherapy.