= diffuse infiltration of bone / soft tissue by hemangiomatous / lymphangiomatous lesions

Age: first 3 decades of life

May be associated with:

• chylothorax, chyloperitoneum, lymphedema, hepatosplenomegaly, cystic hygroma

1. OSSEOUS ANGIOMATOSIS (30–40%)
   • indolent course
   • Location: femur >ribs >spine >pelvis >humerus >scapula >other long bones >clavicle
   • osteolysis with honeycomb / latticework (“hole-within-hole”) appearance
   • may occur on both sides of joint
   • DDx: solitary osseous hemangioma
2. CYSTIC ANGIOMATOSIS
   = extensive involvement of bone
   Histo: endothelium-lined cysts in bone
   Peak age: 10–15 years (range, 3 months to 55 years)
   Location: long bones, skull, flat bones
   • size of 1–2 mm to several cm
   • multiple osteolytic metaphyseal lesions with fine sclerotic margins + relative sparing of medullary cavity
   • may show overgrowth of long bone
   • endosteal thickening
   • sometimes associated with soft-tissue mass ± phleboliths
   • chylous pleural effusion suggests fatal prognosis
   
   DDx: (other polyostotic diseases like) histiocytosis X, fibrous dysplasia, metastases, Gaucher disease, congenital fibromatosis, Maffucci syndrome, neurofibromatosis, enchondromatosis
3. SOFT-TISSUE ANGIOMATOSIS (60–70%)
   = VISCERAL ANGIOMATOSIS
   • poor prognosis
4. Angiomatous syndromes
   Maffucci, Osler-Weber-Rendu, Klippel-Trénaunay-Weber, Kasabach-Merritt, Gorham