Endocrine Abstracts

Gorham-Stout disease is a rare, potentially life threatening skeletal disorder of unknown aetiology. It is characterized by local proliferation of abnormal vessels associated with profound osteolysis. Optimum treatment remains to be established. Herein we report the case of a 45-year-old woman who presented with left-sided thoracic pain, which had gradually increased over the last nine months. Physical examination revealed a primary lymphoedema of the left arm, which had developed 26 years ago, and a segmental bluish cutaneous lesion on the left anterolateral thorax, that had manifested during her second pregnancy 15 years ago. X-ray studies of the left lateral thorax showed extensive destruction of the ribs 9-11 with loss of continuity, which was confirmed by computed tomography scans including 3D-reconstruction. Bone scintigraphy showed an increased uptake of all ribs of the left posterior hemithorax. Histological examination of a rib biopsy revealed angiomatous hypervascularization and intracortical fibrosis, consistent with Gorham-Stout disease. MRI scan results indicated angioneogenesis within the bone marrow of the affected ribs. Histopathological analysis of the skin lesion on the left thorax revealed a cutaneous lymphangioma. Analysis of bone turnover demonstrated normal bone resorption (urinary crosslinks) and normal bone formation (serum osteocalcin) possibly due to the strictly localised nature of bone destruction. Vitamin D metabolites, calcium, phosphorus, and PTH were within the normal range. However, interleukin 6 (8.4 picograms per mililitre) and bone TRAP (4.6 Units per litre) were found to be slightly elevated. Initiation of bisphosphonate therapy (pamidronate 30 miligrams i.v. every three months) led to the disappearance of local pain and to radiological disease stabilisation during nine months of follow-up. Our findings support the view that angiomatous changes in Gorham-Stout disease may trigger bone destruction via local activation of osteoclasts. Inhibition of osteoclast activity by bisphosphonates may halt disease progression.
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