How do you work up a young patient with increasing ferritin and normal TSAT without infectious, inflammatory, or liver disorders?

This is a tough one. If the ferritin is increasing and the TSAT is normal and there is no evidence of hemochromatosis, the ONLY possible explanation is some underlying morbidity, inflammatory, rheumatologic, malignant, or infectious is present. In pediatrics, HLH (hemophagocytic lymphohistiocytosi...