Extremely Pruritic Skin on 52-Year-Old Patient

A 52-year-old male presents with a 3-month history of extremely pruritic skin on the wrist and hand. On exam the patient exhibits generalized erythroderma and lymphadenopathy. What is the diagnosis?

A 52-year-old male presents with a 3-month history of extremely pruritic skin on the wrist and hand. On exam the patient exhibits generalized erythroderma and lymphadenopathy. Peripheral blood smear is performed.

The diagnosis is: