Histologic and PET/CT images from a 52-year-old woman with typical CLL followed at the Department Hematology-Oncology, Azienda Ospedaliera Pugliese-Ciaccio, Catanzaro, Italy. The patient progressed from Rai stage 0 to Rai stage II after a 4-year history of indolent, untreated disease. PET/CT was performed because of increasing abdominal pain, constitutional symptoms, and high LDH levels. (A,B) Coronal PET/CT images demonstrate diffusely increased ¹⁸F-FDG uptake at the abdominal level within a bulky lymph node involvement. Biopsy of a neck lymph node was performed. (C) At low magnification (hematoxylin and eosin [H&E] stain, Olympus objective lens ×10), lymph node histology revealed proliferation centers characterized by prolymphocytes and paraimmunoblasts surrounded by a background of small lymphocytes. Large prolymphocytes at high magnification (Olympus objective lens ×20) highlighted by positive H&E stain (D), Ki-67 (E), and MUM-1 (F). Lymph node histology is consistent with HA-CLL. Image courtesy of Dr Luigi Tucci, Azienda Ospedaliera Pugliese-Ciaccio, Catanzaro, Italy.