In total, 13 skin biopsies were performed in all patients. Sections (4 µm thick) from the formalin-fixed paraffin-embedded blocks were stained with hematoxylin-eosin. Sections were also stained with pan B-cell marker (CD20, mouse anti–human monoclonal L26), pan T-cell marker (CD45RO, mouse anti–human monoclonal UCHL1, and CD3, rabbit anti–human polyclonal antibody), and anti–Epstein-Barr viral (EBV) proteins (mouse monoclonal CS1-4) (all obtained from DAKO Ltd, Glostrup, Denmark) using the standard streptavidin-biotin immunoperoxidase technique. In 2 cases, parts of the biopsy specimens were frozen in liquid nitrogen. Direct immunofluorescence with antibodies against IgG, IgM, IgA, C3, and fibrinogen was performed. In all cases of B-cell lymphoma or leukemia, to detect malignant cells in the infiltrate, the polymerase chain reaction performed on the paraffin-embedded sections was used as previously described.8 In brief, DNA was extracted from 5-µm-thick sections of the paraffin-embedded blocks and was amplified using the seminested procedure with primers Fr3A and LJH in the first 30-cycle round and Fr3A and VLJH in the second 20-cycle round. Each reaction contained DNA, 1 µL; the selected primers, 10 pmol; each deoxynucleotide triphosphate, 200 µmol/L; magnesium chloride, 4 or 5 mmol/L; dimethyl sulfoxide, 10% vol/vol; and Taq polymerase and buffer, 0.2 U, supplied by the manufacturer (Bioline, London, England). The first round of the polymerase chain reaction cycle consisted of annealing for 30 seconds at 56°C, extension for 1 minute at 72°C, and denaturation for 30 seconds at 94°C. The annealing temperature in the second round was 60°C. Before each round, the reaction was heated to 94°C for 4 minutes, and after each round, a final extension step of 6 minutes was performed. Polymerase chain reaction–amplified material was electrophoresed in 2% agarose gel in Tris-boric acid EDTA (TBE) buffer, 250 V, for 25 minutes.