Fig. 15. Phakomatous choristoma (Zimmerman's tumor)—A. Typical location of a phakomatous choristoma in the nasal portion of the lower lid of an infant. B. Low-power photomicrograph showing collagenous tissue that has cords and nests of epithelial cells with a prominent basement membrane. Dystrophic calcification is also present (hematoxylin and eosin stain). C. Higher-power view illustrates cells similar to “bladder cells“ seen in cataractous lenses (hematoxylin and eosin stain). (Photos courtesy of William Morris, M.D.)