Fig. 1. Morphological and immunophenotypic findings of the neoplastic cells. (A) Peripheral blood smear showing a typical “hairy” cell (May-Grunwald Giemsa stain, ×1,000). (B) Trephine biopsy showing predominantly “hairy” cells with fried egg appearance and an interstitial nodule of mature appearing lymphoid cells (H & E stain, x600). (C, D) Immunohistochemistry for CD5 and CD23 respectively showing positivity in interstitial nodules of lymphoid cells (Hematoxylin counterstain, ×400). (E, F) Immunohistochemistry for CD20 and DBA.44 highlighting the “hairy” cells and negative in lymphoid nodule (Hematoxylin counterstain, ×400).