Abstract
Abstract: :
Purpose: Primary intraocular lymphoma, a form of primary central nervous system lymphoma, is a diffuse large B-cell lymphoma showing immunoglobulin heavy chain (IgH) gene rearrangements. Its pathogenesis remains unknown but may be linked to certain infectious agents. Our purpose was to report a small case series of severe toxoplasmic retinochoroiditis and vitritis in which 2 of 3 patients showed lymphoma cells in their vitreous specimen Methods: Among the 654 uveitis patients seen in the Uveitis Clinic at La Source Eye Center since January1995, 67 patients (10.2%) were diagnosed with ocular toxoplasmosis. Three patients with severe evolving inflammation despite maximal therapy underwent vitrectomy because of persistent retinitis and/or vitritis. Vitreous specimen were used to detect the presence of T. gondii DNA by PCR and to perform screening for lymphoma cells by microdissection and PCR demonstration of gene rearrangement of immunoglobulin heavy chains. The lymphoma cells were further evaluated to detect the presence of T. gondii genes within lymphoma cells using T. Gondii B1 gene-specific PCR primers. Results: All three patients had a highly positive IgG serology for T. Gondii and PCR for T. gondii was positive in the vitreous samples from 2 cases. In two of three patients with typical features of ocular toxoplasmosis, lymphoma cells were identified in their vitreous and in one case T. gondii genes but not EBV nor HHV-8 genes were detected in the lymphoma cells. Inflammation had lasted 11 months and 29 years respectively in the two lymphoma-positive patients while in the other patient the retinitis was healed at the time of vitrectomy performed for heavy residual vitreous infiltration at 5 months. Conclusion: Using microdissection and PCR techniques, lymphoma cells were unsuspectedly detected in two of three patients with typical ocular toxoplasmosis. Moreover T. Gondii DNA was detected in lymphoma cells of one of the two patients, raising the question whether T. gondii can play a role in lymphomagenesis.
Keywords: 570 retinochoroiditis • 612 uveitis-clinical/animal model • 496 oncology