Gorham-Stout Syndrome of the Shoulder Girdle Successfully Controlled by Antiresorptive Agents: A Report of 2 Cases

Difficult Therapeutic Decisions in Gorham-Stout Disease-Case Report and Review of the Literature

Gorham-Stout disease (GSD) is a very rare, life-threatening condition characterized by the proliferation of lymphatic vessels and osteolysis. Unfortunately, no standard treatment has been determined for management of GSD. The available therapies are not equally effective and carry substantial side-effects. We report a 42-year-old female with GSD manifested in multifocal osteolysis and chronic chylothorax and ascites. The combined treatment with sirolimus and zoledronic acid due to its synergism of action was introduced. To our knowledge, this is the first Polish case report of adult patients with Gorham-Stout disease.

Off-label uses of denosumab in metabolic bone diseases

Denosumab (Dmab), a monoclonal antibody against the receptor activator of nuclear factor-κB (RANK) ligand (RANKL) which substantially suppresses osteoclast activity, has been approved for the treatment of common metabolic bone diseases, including postmenopausal osteoporosis, male osteoporosis, and glucocorticoid-induced osteoporosis, in which the pathway of the RANK/RANKL/osteoprotegerin is dysregulated. However, the imbalance of RANKL/RANK/osteoprotegerin is also implicated in the pathogenesis of several other rare metabolic bone diseases, including Juvenile Paget disease, fibrous dysplasia, Hajdu Cheney syndrome and Langerhans cell histiocytosis, thus rendering Dmab a potential treatment option for these diseases. Dmab has been also administered off-label in selected patients (e.g., with Paget's disease, osteogenesis imperfecta, aneurysmal bone cysts) due to contraindications or unresponsiveness to standard treatment, such as bisphosphonates. Moreover, Dmab was administered to improve hypercalcemia induced by various diseases, including primary hyperparathyroidism, tuberculosis and immobilization. The aim of this review is to summarize existing evidence on off-label uses of Dmab in metabolic bone diseases and provide opinion for or against its use, which should be always considered on an individual basis.