PMC6724429_01
Pathologic findings in an inguinal lymph node core biopsy. (a) Germinal center showing large atypical plasmablasts. The arrow indicates the germinal center (H&E, 200x). (b) Germinal center, arrows point to plasmablasts (H&E, 500x). (c) The plasmablasts (arrow) are positive for HHV-8 (immunostaining, anti-HHV-8 (13b10) mouse monoclonal antibody by Cell Marque, 200x). (d, e) The germinal center (black arrows) contains lambda-light chain-restricted plasmablasts (in situ hybridization, DNA probes by Ventana that react with lambda mRNA and Kappa mRNA, respectively, 200x). The paracortex adjacent to the germinal center contains polyclonal plasma cells (blue arrows). (f) EBV-positive cells throughout the lymph node core biopsy (EBER in situ hybridization, DNA probe to EBV-encoded RNA-1 by Ventana, 100x).
CRIHEM2019-4536157.001.jpg
PMC6724429_01_CRIHEM2019-4536157.001.jpg
fig1
Some of these atypical germinal centers showed lambda-light chain restriction of the plasmablasts, meeting the criteria of HHV-8-positive GLPD (Figure 1).
Primary effusion lymphoma, cell block preparation. (a) Large atypical cells with irregular nuclei and visible nucleoli (H&E, 1000x). (b) The large cells in the pleural effusion are positive for HHV-8 (immunostaining, anti-HHV-8 (13B10) mouse monoclonal antibody by Cell Marque, 1000x).
CRIHEM2019-4536157.002.jpg
PMC6724429_01_CRIHEM2019-4536157.002.jpg
fig2
Analysis showed this to be a malignant pleural effusion, which contained abundant large plasmablasts, positive with CD138, MUM1, CD30, HHV-8 LANA immunostaining, and lambda-light chain restricted by in situ hybridization, but negative for CD45, CD20, PAX5, CD79a, and CD3, consistent with PEL (see Figure 2).
PMC6724429_02