Metastatic carcinoma masquerading as scleritis.

A 36-year-old white man abruptly developed painless visual loss in his left eye. Fundoscopic evaluation revealed a shallow left superotemporal retinal detachment with an underlying yellowish choroidal infiltrate. Fluorescein angiography disclosed indistinct choroidal leakage, and both B-scan ultrasonography and computed tomography demonstrated superotemporal thickening of the choroid and the sclera. The patient was diagnosed clinically as having a scleritis and an associated exudative retinal detachment. He was placed on a several months' course of systemic prednisone, and despite this regimen, his condition worsened with the appearance of severe pain, proptosis and displacement of the eye, glaucoma, and intense episcleral and scleral injection. The eye was enucleated and displayed externally a massively thickened sclera superotemporally. Light microscopic evaluation of the enucleated globe revealed an extensively necrotic tumor growing diffusely within the choroid; infiltrating viable tumor cells were discovered within the sclera and episclera. The tumor cells had the characteristics of a well-differentiated, mucin-producing adenocarcinoma. Electron microscopic studies demonstrated lumen-forming tumor cells with apical villi, cytoplasmic pseudolumens, pools of cytoplasmic glycogen, and multiple types of inclusions, including mucin, lipid, and electron-dense secretory granules similar to those in pulmonary Clara cells. These findings were consistent with a bronchiolo-alveolar carcinoma. The patient subsequently developed bilateral reticulo-nodular pulmonary infiltrates, also typical of this tumor. The unusual clinical features of this case of "malignant scleritis" are discussed in light of the final diagnosis.