TPD52 expression in lymphomas and myeloma. Strong cytoplasmic expression of TPD52 in a case of hairy cell leukemia (A; paraffin section from bone marrow trephine; original magnification, × 200). T indicates a bone trabecula. Plasmoblastic lymphoma in an HIV-infected patient (paraffin sections): tumor cells express TPD52 (C; original magnification, × 400) but are CD20^- (E; original magnification, × 400); E indicates oral epithelium. The APAAP technique was used with hematoxylin counterstain. (B,D,F) Tumor cells in a case of undifferentiated myeloma (B; hematoxylin-eosin; original magnification, × 1000). The myeloma cells strongly express CD138 on the cell surface (D; APAAP technique; hematoxylin counterstain; original magnification, × 1000) and TPD52 in the cytoplasm (F; APAAP technique; hematoxylin counterstain; original magnification, × 1000); the arrow points to a TPD52-positive multinucleated myeloma cell. All panels represent paraffin sections from B5-fixed/EDTA decalcified bone marrow trephines.