( ( In ( the ( vertical ( growth phase ) ) ) ) ( , ( ( the melanoma ) ( ( grows ( into ( ( ( ( the dermis ) ( -LRB- ( ( deep ( skin layer ) ) -RRB- ) ) ) and ) ( underlying structures ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (DT the) (JJ vertical) (NN growth) (NN phase))) (, ,) (NP (DT the) (NN melanoma)) (VP (VBZ grows) (PP (IN into) (NP (NP (NP (DT the) (NNS dermis)) (PRN (-LRB- -LRB-) (NP (JJ deep) (NN skin) (NN layer)) (-RRB- -RRB-))) (CC and) (NP (VBG underlying) (NNS structures))))) (. .)))
In the vertical growth phase, the melanoma grows into the dermis (deep skin layer) and underlying structures.
(ROOT (S (NP (JJS Most) (NN skin) (NNS structures)) (VP (VB originate) (PP (IN in) (NP (DT the) (NNS dermis)))) (. .)))