Intraocular lymphoma. Cytologic diagnosis and the role of immunologic markers.

We retrospectively reviewed the cytology and immunohistochemistry of vitreous cells from 14 patients with benign or malignant intraocular diseases. Nine patients had intraocular lymphoma and five had benign forms of diffuse uveitis. The most useful cytologic criteria for lymphoma included an irregular nuclear outline, a coarse chromatin pattern and prominent nucleoli. In several cases, it was necessary to obtain more than one specimen to establish the diagnosis of lymphoma. When vitreous fluid was mixed with a balanced salt solution prior to processing, a resulting artifact interfered with interpretation of the specimen. A diagnosis of lymphoma was established by cytology in all nine patients; immunohistochemical techniques were less sensitive than was cytology.