A case of solid blood.

A 53-year-old man with a noncontributory medical history presented to the hospital with blurry vision, intermittently blue fingers, and slowly progressive dyspnea. Blood test results showed the following: hematocrit, 16% (reference interval, 40%–51%); white blood cells, 15.5 10/ L (reference interval, 4.2 10/ L to 9.1 10/ L); platelet count, 50 10/ L (reference interval, 150 10/ L to 330 10/ L). The phlebotomists had a difficult time drawing the patient’s blood because it would immediately solidify in the tubes (Figure 1).