Incidental diagnosis of Mazabraud syndrome presenting as a lower extremity soft tissue mass: A case report and literature review

Introduction and importance: Mazabraud's syndrome is a rare condition, describing the presence of fibrous bone dysplasia and intramuscular myxomas, with an incidence of 1:1,000,000. The aim of this article is to provide a review of the clinical presentation of Mazabraud's syndrome, including indications for surgical treatment, and follow-up strategies. Case presentation: A 46-year-old woman presented with a 3-month history of a painless mass in the right gluteal region, she referred a rapid increase in the mass's volume in the 3 weeks prior to consultation. Physical examination revealed a solid, non-mobile mass adhered to the deep tissues of the right gluteal region. Magnetic resonance imaging (MRI) identified a probable intramuscular myxoma in the right gluteus, and incidentally evidenced an area suggestive of fibrous dysplasia in the left iliac bone. A total resection of the soft-tissue was performed, obtaining clear surgical margins. Pathology study confirmed the diagnosis of intramuscular myxoma. More than one year after surgical resection, the patient remains asymptomatic and has satisfactory results. Clinical discussion: This case presented some unique features including a solitary myxoma, and contralateral fibrous dysplasia, surgical challenges included preoperative planning, as the myxoma was relatively large, and a careful resection to preserve the tumoral capsule, treatment included resection to attain clear margins, the sparing of healthy muscle proved to be valuable for a rapid postoperative recovery. Conclusion: The diagnosis of Mazabraud's syndrome can be overlooked given its very low incidence. Resection is warranted in symptomatic cases and because of the risk of late recurrence, long-term follow-up is required after surgery.