Hairy cell leukemia presenting as multiple discrete hepatic lesions

Figure 2 Histological findings. A, B: Liver core needle biopsy; C, D: Bone marrow biopsy. A: Infiltration by small to medium-sized tumor cells is seen. In the left lower part of the picture, normal residual liver parenchyma is seen (HE, × 200); B: Immunohistochemical stain for TRAcP is positive in tumor cells (× 200); C: Hairy leukemic cells are seen in the bone marrow (HE, × 400); D: The immunohistochemical stain for TRAcP is positive in hairy cells.