WTF is that? Part 2

Lunch is a jolly affair normally... plenty of banter with colleagues, the odd food fight, complaints about the canteen... But usually pretty harmless.

So today I was asked to peel an orange by one colleague (the duty normally falls to someone else but he's away in Manchester today, obviously 'avin' it large) and I grudgingly acquiesced. Taking the aforementioned fruit I dug my well-bitten nails in and got peeling.

I noted that it was a bit squishy, had it been lying around for a while? Yes indeed, for a couple of weeks, no less. OK, sayeth I, just be aware that it might not be all that nice.

I became aware that the little ball of citrussy delight was coming apart in my hands. I looked down and saw...

WTF is that?????? SERIOUSLY?

I'm guessing it's a kind of tumour. There were no signs of any insects or anything, although a fungal infection could be possible. I don't have access to microbial culture facilities but whatever it is, it's VERRRYY INNNTERRRESSSSTING!!!!