Myelitis. "myelitis" is inflammation of the spinal cord, one type being transverse myelitis where several spinal cord segments are involved by viruses/lupus/etc. "polycystic" refers to multiple cysts in a structure. My research revealed no reference to polycystic myelitis. There is transverse myelitis; there are polycystic ovaries & kidneys. Please provide more info. Where did you learn this term?