Ocular Pathology

Use it to review eye pathology for Ophthalmology Board Review or OKAP. Anatomy and pathology of the human eye. Included solar-lentigo, phakomatous choristoma (phacomatous-choristoma), congenital hereditary endothelial dystrophy, Fuch's dystrophy, bullous keratopathy, conjunctival nevus, syringoma, primary acquired melanosis,carcinoma-in-situ, BIGH3 dystrophy, and other lesions seen in eye-pathology. The cornea, iris, lens, sclera, retina and optic nerve are all seen.

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Wednesday, January 24, 2007

Chalazion or Lipogranulomatous Inflammation

Definition: a localized lipogranulomatous inflammatory condition that involves sebaceous glands of the eyelid presumably due to duct obstruction.
Incidence/ Prevalence: One of the most common lesions of the eyelid.

Etiology: The cause of the duct obstruction is an important issue. Chalazia usually result from obstruction caused by non-infectious obstruction but more importantly may be caused by neoplastic conditions especially sebaceous carcinoma. Also infections, particularly staphylococcus infection of the meibomian glands may cause chalazion.
Clinical: The presentation is usually indolent and painless and may manifest as a thickening in the area of the tarsus or an area of redness. The chalazion may become visible as swelling proceeds to the skin surface (white arrow #1 in image above). The lesion may rupture or even appear as a polypoid mass (white arrow #2). At the time of removal, chalazia may range from a thick viscous yellow material to a fibrous nodule (old lesions).
Histopathology: The lesion features lipogranulomatous inflammation, the proper diagnosis given by pathologists for this lesion. Chalazion is a clinical diagnosis. In paraffin sections, clear circular empty spaces (1 in the figures) presumably represent lipid that has dissolved in the organic solvents during processing. The clear spaces are surrounded by nodular collections of epithelioid histiocytes (2 and arrows). The epithelioid histiocytes have bean shaped, lightly staining nuclei with abundant pink vacuolated cytoplasm. The areas around the granulomata show chronic inflammation with a mixture of inflammatory cells including, neutrophils, lymphocytes, plasma cells, and eosinophils. Occasionally multinucleated giant cells result from the syncytial coalescence of the epithelioid histiocytes (number 4, below and near number 2 above). Obviously this histologic appearance may be produced by many infectious organisms including tuberculosis, cat scratch disease as well as sarcoidosis, and other conditions. Special stains for organisms (Ziehl-Neelsen, Gram, PAS, and GMS stains) are generally performed in cases that show lipogranulomatous inflammation.

Indications for Performing Histologic Sections of Chalazia: Many ophthalmologists do not send specimens from the initial chalazia removed for the first time. However, this may be difficult to explain to the patient when an underlying tumor such as sebaceous carcinoma is discovered sometime later and is now much larger than the initial lesion. The cost of obtaining the histology (which is minimal compared to the procedure costs) does not outweigh the potential risk of missing a treatable lesion. Too many sebaceous carcinomas are diagnosed from “recurrent chalazia” in lesions that were previously excised and discarded.
Treatment: Most ophthalmologists will initially treat patients with warm compresses as many chalazia will resolve in time without surgical curetting. Antibiotics should be given for chalazia caused by infection. Obviously complete excision is indicated for those chalazia caused by neoplasms.

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