Fig. 2

Pathologic gross (a) and microscopic features of thespecimen. b Histological examinations stained with hematoxylin and eosin revealed infiltration of medium-sized cells with irregular nuclei, inconspicuous nucleoli, and many apoptotic bodies(H&E stains × 100). c Immunohistochemical staining showed positive reactivity for CD3(×100). d Immunohistochemical staining showed positive CD56(×100). e In situ hybridization for Epstein-Barr virus-encoded RNA showed positive reaction in atypical cells(×100). f Immunohistochemical staining showed negative CD20(×100)