My brother in law has a lump in the middle of his back. they squeeze it every night and fluid comes out. He said it is a tumor and is malignant, what type of cancer is this. I never heard of a tumor being squeezed and fluid coming out. is there such a thing.
Since when your brother-in-law having this problem.  As long-standing discharging sinus is most probably infection.  It looks like tuberculosis than cancer.  Has some doc did Biopsy from that site.  If not than get it done. Then only diagnosis will confirm.