Hi,Dear,Welcome with your query to HCM.
Studied your query in full depth of its details.Reviewed it in context of your health concerns.
Based On the facts, You mostly seem to suffer from-Lipoma / or the Sebaceous Cyst on the lower left side of back.
Pain in the leg seems to be from Sacro-Iliac
Arthritis or from
Sciatica or from arthritis accompanied and needs to be treated by Ortho-Surgeon accordingly.
Treatment-
This would not need any medicines,but Only Surgery.
So
Second Opinion from Surgeon prior to Surgery is advised for you.
Surgical Excision with or without marsupilisation is needed to treat it.
USG of the lump with FNAC
Biopsy would help to fix the diagnosis prior to surgery.
Hope that ,This reply would help you to plan further treatment soon with your treating doctors.Best of Luck and early recovery.
Welcome any further query in this regard,which would be replied in next
session.
Good Day!!
Dr.Savaskar M.N.
Senior Surgical Specialist