( Histologically ( there ( ( was ( ( ( marked ( proliferation ( of astrocytes ) ) ) ( with ( ( abnormally large ) ( cell bodies ) ) ) ) ( in ( ( ( ( the ( white matter ) ) ( of ( the brain ) ) ) and ) ( ( the ( ( ( white and ) gray ) matter ) ) ( of ( the ( spinal cord ) ) ) ) ) ) ) ) . ) ) )
(ROOT (S (ADVP (RB Histologically)) (NP (EX there)) (VP (VBD was) (VP (VBN marked) (NP (NP (NN proliferation)) (PP (IN of) (NP (NNS astrocytes)))) (PP (IN with) (NP (ADJP (RB abnormally) (JJ large)) (NN cell) (NNS bodies))) (PP (IN in) (NP (NP (NP (DT the) (JJ white) (NN matter)) (PP (IN of) (NP (DT the) (NN brain)))) (CC and) (NP (NP (DT the) (ADJP (JJ white) (CC and) (JJ gray)) (NN matter)) (PP (IN of) (NP (DT the) (JJ spinal) (NN cord)))))))) (. .)))
Histologically there was marked proliferation of astrocytes with abnormally large cell bodies in the white  matter of the brain and the white and gray matter of the spinal cord.
(ROOT (S (NP (NP (JJS Most)) (PP (IN of) (NP (DT the) (JJ gray) (NN matter)))) (VP (VBZ is) (PP (IN on) (NP (NP (DT the) (NN surface)) (PP (IN of) (NP (DT the) (NN brain))))) (, ,) (S (VP (VBG surrounding) (NP (JJ white) (NN matter))))) (. .)))