A 23-year-old male farmer presents with 5 days of fever, chills, myalgia, nausea and vomiting, red-colored urine, and oliguria (100-200ml/day). Physical exam shows periorbital edema, conjunctival edema and hemorrhage, petechiae on the back and axilla, and ecchymoses on the upper arm. Lab results: Hb 180g/L, WBC 60×10<sup>9</sup>/L, platelets 34×10<sup>9</sup>/L, blood smear shows 12% blast cells and 20% atypical lymphocytes, urinalysis reveals RBCs full field and protein (+++). On day 3, he develops sudden right-sided hemiplegia, aphasia, and seizures. By day 4, he is comatose with no response to orbital compression, unequal pupils, right Babinski sign (+), and BP 160/110 mmHg. The most likely diagnosis is: