HI,Welcome to HCM with your query.
By the facts of your query,In my opinion,you seem to have a INCUSION
DERMOID Cyst or Sebaceous Cyst/ or a FB with infection in it lately.or Could be lump pressing on the
nerve filament nearby,due to which it has become painful lump between the Shoulder blades,which needs to be confirmed.
This is because of the old ice pick prick either or could be a boil overlapping the same site,which needs to be confirmed by a
Second Opinion from Surgeon.
Treatment-
Antibiotics/anti-inflammatory treatment if responded would confirm the infective cause of it.
But don't worry as it is not Cancerous and Could be treated by -
Surgical Excision with Biospy,which would confirm further treatment line.
Hope this would help you to plan treatment with your doctor.
Will appreciate hitting thanks and writing review comments to benefit needy patient visitors at HCM like you.
Good day.
Dr.Savaskar M.N.
Senior Surgical Specialist.
M.S.Genl-CVTS.