Limb overgrowth with hypertrophy of soft tissue and bone
• Blue rubber bleb nevus syndrome
Multiple blue-colored, rubbery hemangiomas of skin
Usually resemble cavernous hemangiomas
Gastrointestinal tract frequently involved
• Maffucci syndrome
Multiple hemangiomas of dermis and subcutis and enchondromas
– Cavernous, capillary, and spindle cell hemangiomas common
– Enchondromas most commonly affecting metacarpals and phalanges
Associated with mutations in isocitrate dehydrogenase
– Usually isocitrate dehydrogenase-1
Chondrosarcomas develop in 15-30%
Increased risk of pancreatic, ovarian, and central nervous system malignancies
Microscopic
• Dilated, blood-filled capillaries
Confined to papillary dermis in salmon patch
Involve deeper dermis in port-wine stain
• May have cavernous vessels
Port-Wine Stain Port-wine stain is a vascular hamartoma that usually presents on the head and neck. As the patient ages, it often becomes thicker and more nodular. (Courtesy A. Vidimos, MD.)
Klippel-Trenaunay Syndrome Klippel-Trenaunay syndrome is an extensive port-wine stain affecting an extremity associated with limb overgrowth. (Courtesy A. Vidimos, MD.)
Vascular Hamartoma Vascular hamartomas are usually characterized by closely packed, dilated, thin-walled blood vessels.
Leptomeningeal Involvement in Sturge-Weber Syndrome In Sturge-Weber syndrome, an associated vascular hamartoma involving the ipsilateral meninges may be present.
involving the ipsilateral meninges 
may be present.
