If trans prisoners can get full surgery on the NHS, then female prisoners should be able to get breast reductions. Women needing/wanting one often suffer emotional and physical distress prior to having one. I had back and neck pain for years that no physio, chiropractor or osteopath could fix. I worked out, did lots of back strengthening exercises but couldn't escape the pain until they were reduced. I'm betting there are female prisoners in the same situation. It's also a cheaper operation and needs no ongoing hormones/medication.
I'm betting a woman wanting a breast reduction in prison would get laughed at and sent on her way.
I'd be interested to know the number of gender change surgeries (cos nobody's sex gets changed) per trans prison population are carried out vs the non-prison population. It seems like a relatively high proportion of the trans prison population, given that it's small, get their (sexual) desires pandered to in this way.