Familial expansile osteolysis: An Australian case report of a Paget's Disease Mimic.

We report a case of familial expansile osteolysis (FEO) with multimodality imaging findings and histopathological correlation in a 42-year-old man presenting to a South Australian Emergency Department. FEO is a unique metabolic bone condition that is similar in some respects to Paget's disease but distinct enough in its clinical, radiological and histological findings to be classified as a separate disease process. It is inherited in an autosomal dominant pattern and typified by increased osteoclast activity, medullary expansion, and hearing and dental problems. These changes can lead to significant morbidity with individuals affected suffering from bone pain and pathological fractures. To the best of the authors' knowledge, there are no reported cases in the literature documenting this disease in Australia.