Atypical posterior scleritis mimicking an amelanotic choroidal melanoma. A case report

Purpose: To describe a clinical case of atypical posterior scleritis mimicking an amelanotic choroidal melanoma. Method: Observational case report of a 54-year-old woman who presented to the emergency department with photophobia and blurred vision in her left eye for three days. The development of a raised hypopigmented lesion superior to the papilla with choroidal folds and without vitritis simulated an amelanotic choroidal melanoma. Differential diagnosis took into consideration other compatible entities, including choroidal masses or orbital pseudotumor. Results: The patient was subject to full clinical examination, laboratory test, optical coherence tomography, orbital echography, and magnetic resonance imaging. Treatment with oral prednisone showed a significant improvement in all clinical and anatomical parameters. Discussions: Posterior scleritis is characterized by great clinical variability and sometimes can simulate an amelanotic choroidal melanoma. Performing an appropriate differential diagnosis of a large amelanotic lesion is the most important point during a routine ocular examination due to the implications for the patient. Conclusions: Posterior scleritis is a rare and incompletely understood inflammatory disease that affects the posterior part of the sclera. It can be associated with a range of conditions and very often is underdiagnosed. In about one third of the cases, it is related to some systemic disease, especially to autoimmune entity, so it may require a multidisciplinary approach. This case highlighted the importance of a solid differential diagnosis and an early treatment in order to help prevent the appearance of complications that can limit not only the visual outcome of the patient but even his survival in the most extreme cases. Abbreviations: LE = left eye; RE = right eye; BCVA = best corrected visual acuity; BO = both eyes; IOP = intraocular pressure; OCT = optical coherence tomography; MRI = Magnetic Resonance Imaging