Mazabraud Syndrome: A Case Report With 23 Years of Follow-Up.

Mazabraud syndrome is a rare condition characterized by the coexistence of fibrous dysplasia (FD) and intramuscular myxomas. A 46-year-old woman, initially diagnosed with polyostotic FD at the age of 23, developed a palpable mass on her left arm 15 years later, which proved to be an intramuscular myxoma. A diagnosis of Mazabraud syndrome was made. Over the following two decades, she developed additional intramuscular myxomas. The patient denied surgical excision of the soft tissue lesions and was managed conservatively for symptomatic FD. Radiologic imaging, including MRI and ultrasound, played a crucial role in the diagnosis and the assessment of disease progression. Although both FD and myxomas are benign musculoskeletal abnormalities, close follow-up of the patients is essential to monitor changes in the number, distribution, and extent of lesions that may occasionally undergo malignant transformation. This case underscores the importance of early detection and long-term follow-up of patients with FD who may present with, or eventually develop, intramuscular myxomas, comprising Mazabraud syndrome.