Lymphatic tissue helps to hide malformed node (8)
I believe the answer is:
adenoids
'lymphatic tissue' is the definition.
'adenoids' can be an answer for 'tissue' (I've seen this before). I am not certain of the 'lymphatic' bit.
'helps to hide malformed node' is the wordplay.
'helps' becomes 'aids' ('aid' can be a synonym of 'help').
'to hide' indicates putting letters inside.
'malformed' indicates anagramming the letters.
'node' with letters rearranged gives 'deno'.
'aids' going around 'deno' is 'ADENOIDS'.
Can you help me to learn more?
(Other definitions for adenoids that I've seen before include "Enlarged spongy tissues between back of nose and throat" , "These in the throat aided son" , "Lymph tissue towards back of throat" , "They affect the voice" , "Enlarged spongy tissue between back of nose and throat" .)