A 5-year old Caucasian boy was admitted with a fractured tib…
A 5-year old Caucasian boy was admitted with a fractured tibia following a playground accident. A CBC was ordered on admission: TEST RESULT REFERENCE RANGE RBC 3.6 X 10^6/ul 4.0-5.0 X 10^6/ul WBC 12.5 X 10^3/ul 4-10 X 10^3/ul HGB 10.2 g/dl 13-15 g/dl HCT 27% 37-47% MCV 96.4 fl 80-100 fl MCH 28.3 pg 27-31 pg MCHC 38% 32-36% RETIC COUNT 2% 0.5-1.5% SERUM BILIRUBIN 2.4 mg/dl 0.2-1.3 mg/dl DIRECT ANTIGLOBULIN TEST Negative (RR: negative) Negative Peripheral blood Mod spherocytes, anisocytosis, and polychromasia PLT 250,000/ul 150-450 x 10^3/ul Osmotic Fragility Increased (compared to the control) Normal when compared to control What is the most probable diagnosis?