PMLBCL : Microscopic Features
Comments:
This high magnification view from a case of primary mediastinal large B-cell lymphoma (PMLBCL) resembles mediastinal germ cell tumor (seminoma). The tumor cells have clear cytoplasm and there is sprinkling of lymphocytes in the fibrous septa. Note the two Reed-Sternberg like cells in the center. Features favoring PMLBCL would include: positivity for pan B-cell markers, CD45+, CD117-ve, OCT3/4-ve. The profile would be reverse for seminoma (CD45-ve, CD117+, OCT3/4+).