Laboratory Studies
No laboratory studies are indicated.
Imaging Studies
No imaging studies are indicated.
Procedures
Biopsy
Biopsy (incisional or excisional) is a reasonable and safe method that aids in obtaining a definitive diagnosis. Indications for a biopsy are as follows:
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To rule in or to rule out the possibility of malignancy
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For lesions not obviously benign (symptomatic and/or show growth)
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For neoplasms suggestive of malignancy (HIV-positive patients or chronic unilateral conjunctivitis unresponsive to therapy)
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Therapeutic decision
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To determine the surgical margin in ill-defined lesions
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To exclude the possibility of recurrent neoplastic changes
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To harvest tissue for special studies (ie, flow cytometry)
Frozen section
The most common indication for a frozen section is to determine whether surgical margins are free of tumor (ie, to assess the adequacy of tissue excision).
A frozen section should not be used for an "on-the-spot" diagnosis, since frozen tissue rendered tissue morphology is less optimal for microscopic examination.
Invasive disease can be excluded, but intraepithelial lesions may not.
Conjunctival tissue tends to curl after excision; therefore, it is best to examine after fixation and inking the borders. After obtaining the biopsy, place the tissue flat on a piece of firm paper/cardboard before placing in fixation medium.
Surface tissue sampling
Exfoliative cytology (tissue scraping)
This technique is used commonly to aid in the diagnosis of cervical disease. However, this technique and its role in aiding the ophthalmologist in diagnosing ocular surface lesions are less well defined.
Major limitations include the possibility of false-negative results and its inability to determine the depth of invasion.
Most benign and inflammatory lesions cannot be identified precisely by cytologic methods.
It is useful as a guide for where to obtain a biopsy specimen or resect ill-defined conjunctival lesions.
Impression cytology
Another technique for collecting surface cells, impression cytology uses a cellulose acetate filter paper. When the filter paper is placed in direct contact with the surface cells, the cells adhere to the paper.
Impression cytology is less traumatic than exfoliative cytology.
Intracellular structures are better preserved than with exfoliative cytology.
Limitations are similar to exfoliative cytology; both are not appropriate for identifying intraepithelial tumors.
Histologic Findings
Squamous cell papillomas (eg, infectious papilloma, viral conjunctival papilloma) are composed of multiple branching fronds emanating from a narrow pedunculated base. Individual fronds are surrounded by connective tissue, each having a central vascularized core. Acute and chronic inflammatory cells are found within these fronds. The epithelium is acanthotic, nonkeratinized stratified squamous epithelium without atypia. Numerous goblet cells are seen along with acute inflammatory cells. Koilocytosis is exhibited. The basement membrane is intact.
Limbal papillomas are sessile lesions arising from a broad base with a gelatinous appearance. Corkscrew vascular loops and feeder vessels are seen. The epithelium is acanthotic, displaying varying degrees of pleomorphism and dysplasia. The epithelium surface may be keratinized with foci of parakeratosis within the papillary folds. The basement membrane is intact.
Inverted papillomas exhibit exophytic and endophytic growth patterns. Invagination into the underlying stroma instead of the exophytic growth pattern is exhibited by squamous cell or limbal papillomas, whereas some lesions exhibit a mixture of exophytic and endophytic growth patterns. Unlike inverted papilloma arising in the lateral nasal wall or paranasal sinuses, lesions arising from the conjunctiva tend to be less aggressive in malignant transformation. The lesions are composed of lobules of epithelial cells extending down into the stroma. The lesion may be elevated or umbilicated. Epithelial cells do not demonstrate atypia, and dysplastic changes are uncommon for conjunctival inverted papillomas. The cytoplasm is vacuolated in some cells. They may resemble squamous papilloma or pyogenic granuloma. Numerous goblet cells are intermixed with the epithelium. Cysticlike lesions may be seen secondary to the confluence of goblet cells. The lesion may contain melanin granules and/or melanocytes.
