Question: A 59-year-old man presented with a 2-week history of left-sided dull abdominal pain. He denied having diarrhea, fever, or weight loss. Physical examination revealed an enlarged spleen 3 cm below the costal margin. Complete blood count revealed isolated thrombocytopenia (platelets 40 × 109/L) with no other coagulation or metabolic abnormalities. Abdominal ultrasonography showed splenomegaly with a normal liver. Contrast-enhanced computed tomography of the chest and abdomen revealed low-density masses in the spleen with marked splenomegaly measuring 22 cm craniocaudally (Figure A, B).