Orandas with white lumps - is it nodular disease?

Please help me.... I'm a relatively new fishkeeper and started off with a moor and oranda...the moor died within a week and had four white lumps on his body which i mistakingly took as ich.

My tank has been going for two months now and the oranda which i bought with the dead moor developed a huge white lump on its top fin (which had been clamped down for weeks) and after another huge lump started to develop on her side i spent an hour researching and put it down to NODULAR DISEASE and humanely disposed of the fish straight away so as to save the others.

A week later.....my healthy-looking oranda has two small white lumps on its head. It's not cauliflower-like and matches the appearence of the lump on the dead oranda.

This fish seems perfectly healthy! Water quality is good.

There are left in my tank a moor, the oranda, a comet and normal goldfish and a chinese hillstream loach.

ANY ADVICE WOULD BE VERY APPRECIATED! Thankyou