Collagen-Rich Crystalloids in a Scarred Vascularized Cornea

Abstract Collagen-rich crystalloids, also referred to as collagenous crystalloids, are uncommon findings in benign salivary gland tumors with myoepithelial differentiation and in cutaneous neoplasms. Herein, we report the presence of collagen-rich crystalloids in the scarred, vascularized cornea of a 56-year-old woman. The patient underwent penetrating keratoplasty, and microscopic examination of hematoxylin-eosin–stained sections disclosed large aggregates of refractile material within the corneal stroma. The deposits were partially birefringent when viewed with polarized light and composed of radially arranged columns (long rectangles) with rounded to pointed tips. The deposits had tinctorial properties of collagen using Masson trichrome and the van Gieson method for collagen, and they stained with Alcian blue, pH 2.5, and Verhoeff elastic stain. They did not stain with Gomori methenamine silver, Snook reticulin stain, or tyrosine using the Baker modification of the Millon reaction. This is the first report, to our knowledge, of collagen-rich crystalloids in the cornea. Their presence in the cornea indicates that these structures may occur in the absence of neoplasia.