BAD-LAMP is a marker of blastic pDC neoplasms. (A) Immunohistochemistry on paraffin sections of skin lesions from patients with BPDCNs reveal a massive infiltration of BAD-LAMP⁺ cells (arrows, ×400). Negative staining with mouse IgG isotype control is shown on the right. (B) A larger-scale analysis by tissue arrays revealed that > 78% of biopsies were BAD-LAMP⁺ among 33 patients diagnosed with a CD4⁺/CD56⁺ malignancy (left). An example of a BAD-LAMP⁺ biopsy from the tissue array is also shown (right).