( ( ( White ( blood cells ) ) ( -LRB- ( leukocytes -RRB- ) ) ) ( ( may ( be present ) ) . ) )
(ROOT (S (NP (NP (NNP White) (NN blood) (NNS cells)) (PRN (-LRB- -LRB-) (NP (NNS leukocytes)) (-RRB- -RRB-))) (VP (MD may) (VP (VB be) (ADJP (JJ present)))) (. .)))
White blood cells (leukocytes) may be present.
(ROOT (S (NP (JJ Leukocytes) (NN blood) (NNS cells)) (VP (VBP are) (ADJP (JJ white))) (. .)))