Case 41. Reference case 41B

　 　 　 　
　 Infectious mononucleosis, showing epipharyngeal swelling in a 10 year-old boy (biopsy, HE). 　
　 　 　 　

　

 　 EBER-1 is demonstrated in the nuclei of small-sized B-cells, while the activated T-cells are negative. The lesion diminished in size in one week.