Skeletal cystic angiomatosis: A rare cause of unilateral lytic bone lesions

Cystic angiomatosis is a rare, benign, multifocal disorder of bone and viscera. Angiomatous deposits result in bone lysis and organ dysfunction. Bony cystic lesions occur in the axial and proximal appendicular skeleton. Lesions may cause bone pain or pathological fracture. Diagnosis is difficult, of exclusion and demands a biopsy. The prognosis varies upon whether the lesions are solely skeletal or there is visceral involvement. A 71-year-old man reports increasing symptoms of painful swelling in the right thoracic wall for over a month. The swelling was bony hard in consistency. Except for his bony swelling, the patient’s physical examination was within normal limits, as were all his laboratory studies. X-ray imagery showed multicystic expansive lytic areas involving the right ribs. Computerized tomography, magnetic resonance imagery and gallium bone scan revealed lytic lesions of multiple right ribs, and cervical, dorsal, lumbar and sacrum iliac spine. A right rib biopsy has shown a cystic formation with endothelial walls. Five years later, the patient remained stable, with no clinical, laboratory or imagilogic progression of disease and without visceral involvement. This case is presented in his rarity and differential diagnosis challenge.