11yr old son cbc shows high lymphocyte % and low mpv, low creat, and high alkaline phos. symptoms of fatigue, pale skin, headache, rashes- leukemia?

Doubt it: Rare things rarely happen. A kid with frank leukemia doesn't just have a high percentage of lymph's, they are often the only things seen & number in the hundreds of thousands. The data presented is minimal. From the numbers this could easily be a simple viral illness.

Stop worrying: Percentages are meaningless. All that matters is absolute counts of lymphs and neutrophils. All 11 year olds have high alkaline phosphate. Mean platelet volume means nothing. Low creatinine is never a first warning. If he's not anemic and there are no abnormal cells noted, stop worrying about leukemia. The most common cause of headaches in a boy his age is needing glasses.