phlebomyomatosis

phleb·o·my·o·ma·to·sis

(fleb'ō-mī'ō-mă-tō'sis),
Thickening of the walls of a vein by an overgrowth of muscular fibers arranged irregularly, intersecting each other without any definite relation to the axis of the vessel.
[phlebo- + myoma + G. -osis, condition]

phlebomyomatosis

(flĕb″ō-mī″ō-mă-tō′sĭs) [″ + mys, muscle, + oma, tumor, + osis, condition]
Thickening of the tissue of a vein from an overgrowth of muscular fibers.