Ocular Cytopathology

An atlas that features the cytologic findings of the normal features and diseases of the eye.

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Tuesday, October 04, 2005


Some granulomatous lesions of the orbit may be differentiated from each other by fine needle aspiration cytology. Eosinophilic granuloma, ruptured dermoid cyst, and chalazion are so characteristic that the diagnosis can be suggested and usually made definitely with cytology alone. However, in certain cases, ancillary tests are helpful (e.g., electron microscopy for eosinophilic granuloma).

Foreign-body Granuloma
Foreign-body granuloma may present with a subconjunctival or orbital lesion. Frequently, patients will not be aware of a previous injury or implanted foreign material. Patients may present with a red eye and reduced eye movements. There may be a yellow infiltrate under the conjunctiva that mimics lymphoma. CT scan may reveal a mass (Figure 10-17).
Fine needle aspiration demonstrates a granuloma with foreign-body giant cells (Figure 10-18). Infectious causes of granulomatous inflammation should be excluded with culture and special stains. This can be accomplished by fine needle aspiration. [41] Biopsy is usually necessary to uncover the foreign body (Figure 10-19).

Chalazia are lipogranulomatous reactions that occur in the eyelid because of meibomian gland obstruction. They may be associated with infection or neoplasms, but are usually secondary to inspissated secretions. [42] Usually, the diagnosis is obvious clinically and no biopsy is necessary. In longstanding cases, the chalazion may present as a discrete mass. Fine needle biopsy may be done to rule out sebaceous carcinoma or abscess. [3, 43] Smears of the aspiration show numerous histiocytes with foamy cytoplasm and occasional granulation tissue (Figure 10-20). Treatment of this lesion may include observation or removal by curettage.

Ruptured Dermoid Cysts
Dermoid cysts are congenital lesions that represent arrested migration of ectoderm entrapped in orbital soft tissue or between sutures of orbital bone. [44] They are the most common orbital tumor in children. It is preferable not to aspirate a dermoid cyst to avoid spillage of its contents. However, deep dermoids are frequently difficult to diagnose clinically. This type of dermoid cyst presents in adulthood as a slowly growing mass in the supero-temporal orbit. There is often extension through bone sutures that can be confused with boney erosion of lacrimal gland tumors. [45] Seven fine needle aspiration biopsies of dermoid cysts have been reported and all presented as adults and at least two of them had bone involvement. In at least two of the cases, there was a history of a tumor since childhood and the diagnosis was easily made by fine needle aspiration. [46, 47] In others, malignancy was clinically suspected. In one case, the cytologic findings were even reported malignant (a false positive), but details are not enclose. Fine needle aspiration of an unruptured dermoid cyst contains anucleate squamous cells, keratin debris, and, occasionally, hair shafts. A ruptured dermoid cyst will also contain granulomatous inflammation with multinucleated giant cells (Figures 10-21 and 10-22). We have not seen adnexal structures of the cyst wall in the four dermoid cysts we have examined cytologically.


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