Echographic pseudoextension of uveal melanomas

Background: Standardized echography is routinely utilized to assess uveal melanomas. Echographic pseudoextension is defined as normal structures mimicking intrascleral or extrascleral extension of tumor on echography. Methods: The records of 151 consecutive uveal melanoma patients evaluated with standardized echography over a 6-year period (1986–1991) were reviewed to identify those in which pseudoextension or true extension was diagnosed. Results: Fourteen (9%) cases of pseudoextension were noted, with causes including juxtapapillary tumor location (seven cases), extraocular muscle insertion (five cases), vortex ampullae (one case), and post-brachytherapy changes (one case). Clinical, echographic, and/or histopathologic follow-up confirmed absence of true extension. Six (4%) cases of true extrascleral extension were identified and confirmed histopathologically. Conclusion: Differentiating extraocular tumor extension from pseudoextension is critical, and use of standardized A-scan and contact B-scan echography is integral in this assessment.