Guided case: warming changes the count, not the story

The specimen was collected at 08:10 and analyzed at 08:42 on the declared analyzer. WBC was 7.2 × 10^9/L, RBC 2.95 × 10^12/L, hemoglobin 13.6 g/dL, hematocrit 29.8%, MCV 101 fL, MCH 46.1 pg, MCHC 45.6 g/dL, and platelets 210 × 10^9/L. The RBC histogram showed an irregular, broad high-volume aggregate pattern; the analyzer flagged RBC agglutination and MCHC check.

The hemoglobin is internally more plausible than the RBC-derived indices because it is read after lysis. Calculating MCHC as 13.6 times 100 divided by 29.8 gives 45.6 g/dL, confirming that the abnormal hematocrit drives the impossible relationship. Room-temperature handling, the flag, and the histogram support suspected cold agglutination rather than true cellular hyperchromia.

The well-mixed EDTA tube was warmed at 37°C for 30 minutes and rerun immediately at 09:20. RBC became 4.35 × 10^12/L, hemoglobin 13.7 g/dL, hematocrit 39.4%, MCV 90.6 fL, MCH 31.5 pg, MCHC 34.8 g/dL, and platelets 205 × 10^9/L. The agglutination flag cleared and the histogram became unimodal.

The order remained held until the warmed run, original smear evidence, and internal relationships agreed. The warming action, original result, and final released result were documented through the locally validated procedure. If discordance persisted, the endpoint would be suppression, warm recollection, consultation, or escalation—not an assumed correction.