Impression cytology of melanocytic conjunctival tumours using the Biopore membrane.

PURPOSE To compare a new Biopore membrane impression cytology method with the routinely used exfoliative cytology in patients with a melanocytic lesion of the conjunctiva. METHODS Sixty-eight consecutive patients with a conjunctival melanocytic lesion underwent Biopore membrane impression cytology as well as exfoliative cytology. A histologic sample was also available in 26 cases. All Biopore samples were stained immediately with RAL 555. Both Biopore and exfoliative cytology samples were assessed by two cytopathologists and graded into four different categories of atypia. RESULTS Twenty-three out of 26 Biopores and 20 out of 24 for the exfoliative smears correlated with the corresponding histologic sample. Biopore cytology resulted in higher numbers of cells with a greater density compared to exfoliative cytology. CONCLUSIONS Biopore cytology can be used for cytologic sampling of conjunctival melanocytic lesions. Because of the larger amount and higher density of cells obtained with the Biopore membrane, interpretation by a pathologist is easier and faster. Sampling of the fornix, caruncula, and ocular material in children is difficult with the Biopore method, and exfoliative cytology seems to be the favorable test in those situations.