hi..thanks for your query
is not likely in the case you mention.Psoriasis is a common skin condition where the skin lesions are red with silver-white patches called scales.It does not present like a lump under the skin and has no relation with bone , except for the condition called Psoriatic arthopathy which is a arthritis
developing in some people having psoriasis.It involves joints of the body like upper extremities especially the hands,small joints of the feet ,hips, knees, and ankles.
I think that the only way you confirm the diagnosis is the scan that you are doing .So please do the investigations to be guided into the appropriate management.
Hope this is helpful.