Retrospective cytological study of intraocular lymphoma using vitreous and intraocular perfusion fluid

Intraocular lymphoma (IOL) is an extremely rare tumor. We carried out a retrospective cytopathological study with vitreous and intraocular perfusion fluid obtained on conducting a pars plana vitrectomy in 18 cases of IOL. In the 18 cases, nine were patients of Kansai Medical University Takii Hospital from 1991 to 2007, and the other nine had already been reported by other hospitals. Most patients were male, and the average age at onset was 60.4-year-old. The main symptoms were vitreous opacity, amblyopia, and blurred vision. Cases of primary intraocular lymphoma numbered 8/15 (53%), while cases of infiltration of malignant lymphoma from the brain numbered 2/15 (13%). Although IOL contains various subtypes of lymphoma, the most frequent subtype is diffuse large B-cell type lymphoma. It has been reported that making a definite diagnosis of IOL is difficult because the clinical symptoms and examinations are similar to chronic uveitis, and so IOL is called "masquerade syndrome." Recently, serological and molecular pathological studies have been carried out in addition to morphological examination. However, a cytological diagnosis based on the clinical background and/or image findings is important for the diagnosis of IOL, because of the volume limit of the vitreous fluid and difficulty of obtaining specimens from the inside of the eyes.