Corneal Involvement in Xeroderma Pigmentosum;a Histopathologic Report
A 19-year-old male subject and a known case of XP was referred to our clinic with bilateral corneal opacification and loss of vision, more severe in the right eye, from childhood. There was no document regarding cutaneous tumor or malignancy. Gross examination revealed widespread hyperpigmentation of the eyelids and slitlamp examination disclosed severe corneal opacification accompanied by stromal neovascularization and lipid deposits. Due to severity of the condition, the right eye underwent penetrating keratoplasty.\nThe corneal button was sent to the pathology laboratory of the Eye Bank of I.R. of Iran. The specimen was approximately 7 mm in diameter, yellowish-white in color and completely opacified. The corneal disc was cut into two halves and fine tissue sections were made after histological preparation which then underwent hematoxylin and eosin (H&E), Congo red, periodic acid Schiff (PAS) and Gram staining. Light microscopy of H&E stained sections revealed corneal thickness to about 2 mm (), irregular and somehow thinned epithelium with basal and subepithelial bullous changes (). Extensive foci of stromal neovascularization accompanied by chronic granulomatous inflammation () with giant multinuclear cells () surrounding intrastromal cholesterol clefts () were seen. The Descemet membrane had apparently normal thickness, however endothelial cell count was severely reduced (). There was patchy destruction of Bowman’s layer replaced by fibrous tissue. Congo red staining was negative for amyloid deposits and no microorganisms were detected on Gram and PAS staining. The observed histopathological changes were compatible with chronic interstitial lipogranulomatous keratitis.