A registered pension scheme may be able to commute some or all of the members benefits due to serious ill health
It can only be paid out of uncrystalised funds (or unused funds post 75) and the member must have some LTA remaining but there is no limit to the amount that can be paid.
If the member is under 75 the payment is tax free up to the LTA and the excess would be charged 55%.
If the member is over 75 the whole lump is taxed via PAYE.