Fig. 2. (A) Microscopically, skin biopsy specimen revealed diffuse infiltration of small to intermediate lymphoid cells in the dermis and subcutaneous fat (hematoxylin & eosin [H&E], original magnification ×200). (B) High magnification shows monotonous tumor cells with slightly convoluted nuclei with fine chromatin and occasionally nucleolus and scant cytoplasm (H&E, original magnification ×1,000). (C-F) Photographs of immunohistochemical staining. Most tumor cells are positive for leukocyte common antigen (LCA) (C), CD79a (D), paired box 5 (PAX5) (E), and terminal deoxynucleotidyl transferase (TdT) (F).