neurosurgeon stated it resembled a "bunch of grapes"...

In May of this year i had a discectomy of the L5-S1....3 weeks following surgery i noticed/developed a lump in my lower back at the incsion site the size of golf ball. The neurologist ordered a sonogram that threw off some very peculiar waves and the radiologist recomended MRI--by august after tests it was decided that it should be removed. My neurosurgeon stated she had never seen anything like it...it resembled a "bunch of grapes" some even looked necrotic. Now it has come back, even larger and tender. I was sent to a plastic surgeon and he said he has no idea what this is. Please, please...has anyone ever heard of this????