The Natural History of Fibrous Dysplasia of the Orbit.

BACKGROUND: Orbital fibrous dysplasia (FD) is a disease of disordered fibro-osseous proliferation secondary to altered osteogenesis, with potential sequelae including compressive neuropathy and irreversible vision loss. The purpose of this study was to evaluate the natural history and longitudinal outcomes of 37 patients with orbital FD who underwent stratified surgical management. METHODS: All patients treated for FD from 2015-2021 were identified, yielding 185 patients, 39 with orbital involvement. Impressions from head CTs were analyzed by a craniofacial radiologist to evaluate location and timing of tumor growth. Operative records were reviewed to determine surgical approach (partial excision/contouring, complete excision, or partial excision with optic nerve decompression). RESULTS: Average age at diagnosis was 10.7±4.5 years, with average follow up of 5.2±4.7 years. Of the 37 patients with orbital involvement, 28 (75.7%) had optic canal involvement. Of those with optic canal involvement, 13 (46.4%) required partial excision with optic nerve decompression while 15 (53.6%) did not. Of those without optic canal involvement, two patients (22.2%) underwent partial excision/contouring of the anterior orbit to correct dystopia and/or proptosis and four patients (44.4%) underwent complete excision of the orbital component and reconstruction with bone graft or mesh. Younger age at diagnosis was associated with an increased number of surgical interventions (p=.011), younger age at first optic canal decompression (p=.003) and worse visual outcomes (p=.009). CONCLUSIONS: In our cohort, patients diagnosed at a younger age required more surgeries, underwent decompression earlier, and had worse visual outcomes.

Tubulinopathies.

Mutations causing dysfunction of the tubulins and microtubule-associated proteins, otherwise known as tubulinopathies, are a group of recently described entities, that lead to complex brain malformations. An understanding of the fundamental principles of operation of the cytoskeleton and compounds in particular microtubules, actin, and microtubule-associated proteins, can assist in the interpretation of the imaging findings of tubulinopathies. Somewhat consistent morphological imaging patterns have been described in tubulinopathies such as dysmorphic basal ganglia-the hallmark (found in 75% of cases), callosal dysgenesis, cerebellar hypoplasia/dysplasia, and cortical malformations, most notably lissencephaly. Recognizing the common imaging phenotypes present in tubulinopathies can prove invaluable in directing the genetic workup for a patient with brain malformations.