Sebaceous cyst that became infected,
My father used to take them out under local in his (GP's) surgery
but that was in the fifties.
He also said amazingly because it is linked to your question that as a surgical principle if if there was something (in this case a hair follicle) that should drain naturally and it got blocked, then an infection would occur behind the block. [works well for kidney and gall stones ]
and this seems to be true - I wouldnt be surprised if Paget or Hunter described it first