Hemangioma on L2 and Spondylolisthesis

I have a L4/5 bilateral par interarticularis defect, Grade 2 anterolisthesis, and a moderate narrowing of the neuroforamina bilaterally with minimal lateral recess inpingement bilaterally.  Additionally, it was noted that I have a small hemangioma on the L2.  My Orthopedice surgeon did not mention this to me but it was noted in my MRI report.  I am having tons of issues including:  Severe constipation, Leg burning, pins and needles and numbness on both legs.  Additionally, my leg hand will get pins and needles then go numb.  I am also having all kinds of stabbing and shooting pains in my back as well as the feeling like my nerves are being torn(like a burning/stabbing/shooting) pain in my back as well as in the abdominal region.  My back feels like it is on fire (hot) most of the time, I assume from inflammation since it was noted in the MRI that I have subcutaneous edem in the spine posteriorly.  First, I asked the Doctor if the back problems were causing constipation and he stated they were not.  I've read on different sites that it would cause constipation.  Second, should I be concerned with the hemangioma?  I understand it to be a benign tumor on the L2 but could that be also causing the pains in my back and other places? I called the Dr. to ask whether or not I should be concerned with teh hemanigoma and he did not call back.  I go in for a lumbar fusion with decompressionand interbody on sept 28.  I am wondering if I should be seeing a neurologist?  If the hemangioma should be removed while in doing other things on the 28th.  I am concerned as my 11 yr old nephew has histocytosis X and lytic lesions on his spine, shoulder, and skull.  They are aggessive benign tumors that literally destroy bone.  
Any help would be greatly appreciated.