weird growth on a cabbage leaf

[manicscousers]

i know there are some scale insects on this leaf but what on earth has caused the strange growth on this cabbage..I've removed the leaf , there are no more but..what about the rest of the brassicas in the bed, will they be ok ? ???

[manicscousers]

[Multiveg]

White blister rot.

[saddad]

Never heard of it, or seen it thankfully.
:-[

[manicscousers]

whatever it was, the leaf is destroyed and the rest of the cabbage is growing ok  :)