A chalazion is a chronic, often painless nodule of the eyelid that develops when the lipid secretions of the meibomian glands or, less often, the glands of Zeis are discharged into the surrounding tissues, inciting a lipogranulomatous reaction (Fig 13-7).
Figure 13-5 Molluscum contagiosum involving the eyelid margin (arrow). Note the associated follicular conjunctivitis.
Figure 13-6 Molluscum contagiosum. A, Note the cup-shaped, thickened epidermis with a central crater. B, In the more central portion of the epidermis, cell nuclei are displaced peripherally by large eosinophilic viral inclusions known as molluscum bodies (arrows). The molluscum bodies become more basophilic near the surface of the epithelium (arrowheads).
(Courtesy of Nasreen A. Syed, MD.)
Figure 13-7 Chalazion. Granulomatous inflammation consisting of epithelioid histiocytes and multinucleated giant cells (arrows) surrounds clear spaces (lipogranuloma). Because the lipid is dissolved by solvents during routine tissue processing, optically clear (“lipid dropout”) spaces remain. Lymphocytes, plasma cells, and neutrophils are also often present.
Excerpted from BCSC 2020-2021 series: Section 4 - Ophthalmic Pathology and Intraocular Tumors. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.