Twenty-Year Follow-up of Monostotic Fibrous Dysplasia of the Second Cervical Vertebra

Abstract

We present a twenty-year follow-up report on a patient with monostotic fibrous dysplasia of C2 treated with posterior spinal fusion from C1 to C3. The short-term results of this case have been presented previously1. This is one of the longest durations of follow-up of monostotic fibrous dysplasia of the spine reported in the literature, and it demonstrated monostotic fibrous dysplasia extending through the fusion mass to involve a previously unaffected vertebra. This behavior may provide new insight into the pathophysiology of fibrous dysplasia. Fibrous dysplasia is a benign intramedullary fibro-osseous lesion originally described by Lichtenstein2 in 1938 and Lichtenstein and Jaffe3 in 1942. Fibrous dysplasia can present in one bone (monostotic fibrous dysplasia) or multiple bones (polyostotic fibrous dysplasia) and can be associated with cafe au lait spots and endocrinopathies (McCune-Albright syndrome) or soft-tissue masses (Mazabraud syndrome). Fibrous dysplasia is relatively common, accounting for approximately 7% of benign bone tumors4. However, monostotic fibrous dysplasia involving the spine is quite rare. Dahlin and Unni5 noted only six cases (1.4%) involving the spine in their review of 418 cases of monostotic fibrous dysplasia. We reviewed the literature to delineate the clinical, radiographic, and pathologic features of monostotic fibrous dysplasia of the spine. Given the rarity of monostotic fibrous dysplasia of the spine, a thorough search of PubMed/MEDLINE was performed with use of the terms “monostotic fibrous dysplasia” and “spine.” The abstracts of all results were then reviewed for relevance. Additional studies were identified by reviewing the references listed in studies found by the literature search. Only studies that clearly delineated the lesions as monostotic fibrous dysplasia and in which an anatomic location within the spine was reported were included. This methodology allowed us to identify more cases of monostotic fibrous dysplasia involving the spine than …