George 17.5 yr NM DSH Presented to local clinic for severe lethargy Treated 5 months prior for severe anemia. Mycoplasma had been the differential and the patient responded to doxycycline. – No data from that episode was reviewed by a pathologist The animal had a Snap FeLV/FIV test at that time which was negative.

George Presented to local clinic for severe lethargy March 22 th. – LaserCyte data: – RBC2.23 M/ul (5-10) – HCT13.4% (30-45) – HGB2.6 g/dl (9-15.1) – MCV60.1 fl (41-58) – MCHCNot provided – RDW21.6%( ) – Retic21.0 K/ul(3-50) WBC37.07 K/ul ( ) Neut %38.9 Lymph %49.8 Mono %7.7 Eos %2.9 PLT210 K/ul ( ) PDW29.7 %

George The clinician was concerned about leukemia based on those results. Blood Film review on 3/24 from sample read by LaserCyte on 3/22. Estimated WBC ~9,700 /ul Manual differential reviewed by pathologist and med tech – Neut %92 – Lymph %3 – Mono %2 – Eos %1 – Bands %2 – Few nRBCs identified (<1 %) – Platelets are present in large clumps, so an estimate was not performed – Red cell morphology: Marked anisocytosis (both microcytes and macrocytes present), 2 + keratocytes, 1+ Howell Jolly bodies, occasional elliptocytes and schistocytes. The few nRBCs present had eosinophilic cytoplasm (as if mature). Mild hypochromasia was noted. – WBC morphology: Mild toxicity- Dohle bodies – No evidence of parasites, but did recommend PCR for Mycoplasma since that was a prior concern.

George – The leukocytosis with lymphocytosis could not be confirmed by blood film review. With so few nRBCs accounted for. We could not determine the cause for the difference between the automated analyzer and the manual film review. – The Catalyst Dx indicated hyperglycemia (214 mg/dl), Increased ALT (586 U/l, ) and ALP (161 U/l, )

George Recommended Bone marrow cytology and re-evaluation of CBC. Also mentioned concern about iron deficiency ADVIA 120 CBC on 3/24 sample WBC: 22,270 /ul Neut %57.3 Lymph %40.6 Mono %0.8 Eos %0.5 LUC %0.8 Manual estimate and Diff – WBC6,800 /ul – Neut%93 – Bands %2 – Lymph%<1 – Mono %3 – Eos %2 – 6 nRBCs counted and the corrected WBC is 21,010 /ul. – Mild toxicity- Dohle bodies, vacuoles

George RBC2.20 M/ul (6-10) HCT9.3 %(30-43) (confirmed with PCV) Hgb2.5g/dl (10-15) MCV42.4 fl (40-50) MCHC26.4 g/dl (31-34) Retic3% (0.066 M/ul) RBC morph: Occasional keratocytes, few polychromatophils, few Howell jolly bodies Platelets332,000 /ul with MPV=32.3 ( ) Few small clumps noted and the analyzer noted (+) clumping. Giant platelets were very common (> the size of an average erythrocyte).

The question Knowing that nRBCs are accounted for, what is causing the leukocytosis with lymphocytosis on the automated analyzers? Do these platelets have inclusions, and could they be mistaken for lymphocytes?

Large platelets Some contain circular or bilobed “inclusions”

Large platelets

Inclusions?

More huge platelets

George A bone marrow was performed. M:E ratio was 1.4. Myeloid precursors showed orderly maturation. Very few early erythroid precursors (blasts) were identified. Most erythroid cells were rubricytes and metarubricytes. Few dysplastic changes in the erythroid lineage were visualized including cells with “normal” hemoglobin (nicely eosinophilic) containing nuclei and multilobulation of the nuclei. Megakaryocytes appeared adequate with orderly maturation observed. The cat was supposed to be transfused, but he died before the procedure. Samples had been sent out for a variety of infectious agents, but these were cancelled. No other diagnostic procedures were performed.