A 55-year-old male farmer presents to the clinic with fever, dizziness, epistaxis, petechiae, and arthralgia for 2 weeks. Laboratory tests show Hb 70g/L, WBC 31.5×10<sup>9</sup>/L, PLT 20×10<sup>9</sup>/L, and peripheral blood smear with blast cells. Which of the following is the most common and significant physical finding?