2020–2021 BCSC Basic and Clinical Science Course™
9 Uveitis and Ocular Inflammation
Chapter 13: Masquerade Syndromes
Neoplastic Masquerade Syndromes
Approximately 5% of patients with uveal melanoma present with signs of ocular inflammation, including episcleritis, anterior or posterior uveitis, or panuveitis. Most tumors that present in this fashion are epithelioid-cell or mixed-cell choroidal melanomas. Ultrasonography is useful in diagnosing atypical cases because of the characteristically low internal reflectivity of these lesions. Management of uveal melanomas is discussed in BCSC Section 4, Ophthalmic Pathology and Intraocular Tumors.
Approximately 1%–3% of retinoblastomas may present with the appearance of inflammation, caused primarily by the relatively rare variant of diffuse infiltrating retinoblastoma. Patients are usually between age 4 and 6 years at presentation. These cases can be diagnostically confusing because of the limited visibility of the fundus and the lack of calcification on radiography or ultrasonography. Patients may have conjunctival chemosis, pseudohypopyon, and vitritis. The pseudohypopyon typically shifts with changes in head position and is usually white as opposed to the yellowish color of inflammatory hypopyon.
Juvenile xanthogranuloma is the result of a histiocytic process affecting mainly the skin and eyes, and, in rare instances, viscera. Patients usually present before the age of 1 year with characteristic reddish-yellow skin lesions. Histologic investigation shows large histiocytes with foamy cytoplasm and Touton giant cells. Ocular lesions can involve the iris and result in a spontaneous hyphema. Iris biopsy samples show fewer foamy histiocytes and fewer Touton giant cells than do skin biopsy specimens. Other ocular structures may rarely be involved. If the skin of the eyelids is involved, the globe is usually spared. Intraocular lesions may respond to topical, periocular, or systemic corticosteroid therapy. Resistant cases may require local resection, radiation, or immunomodulatory therapy.
Zamir E, Wang RC, Krishnakumar S, Aiello Leverant A, Dugel PU, Rao NA. Juvenile xanthogranuloma masquerading as pediatric chronic uveitis: a clinicopathologic study. Surv Ophthalmol. 2001;46(2):164–171.
Excerpted from BCSC 2020-2021 series: Section 9 - Uveitis and Ocular Inflammation. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.