Cystic angiomatosis, a heterogeneous condition

BACKGROUND Cystic angiomatosis (CA) is a rare disorder causing bony cysts. It displays some similarity to Gorham-Stout disease (GSD), but has a much better local prognosis, despite the larger number of cysts. These 2 conditions also differ in terms of their location, visceral involvement, and response to treatment. METHODS We report 4 cases of CA, including 1 sclerosing form, which we compare with cases from a literature review performed with PRISMA methodology. RESULTS We reviewed 38 articles describing 44 other patients. Mean age at diagnosis for the 48 patients (our 4 patients + the 44 from the review) was 22.5 years, and 28 of the patients were men. The femur was involved in 81% (n = 39), the pelvis in 73% (n = 35), the humerus in 52% (n = 25), the skull in 48% (n = 23), and the vertebrae in 44% (n = 21). Visceral lymphangiomatosis (either clinical, or detected on autopsy) was also reported in 35% (n = 18) of the patients. The spleen was the most frequently involved organ (n = 12), followed by the lungs and pleura (n = 8). Liver cysts and/or chylothorax were rarely reported (5 cases), but were invariably fatal. Radiation therapy on bone or soft tissue masses was ineffective, as was interferon alpha, in the 2 patients in which this drug was tested. The efficacy of bisphosphonate was at best equivocal. CONCLUSION The progression of CA is unpredictable and treatments effective against GSD, such as bisphosphonates and radiotherapy, have proved ineffective for this condition. New treatments are thus urgently required.