UTILITY OF MICRODISSECTION AND POLYMERASE-CHAIN-REACTION FOR THE DETECTION OF IMMUNOGLOBULIN GENE REARRANGEMENT AND TRANSLOCATION IN PRIMARY INTRAOCULAR LYMPHOMA

Objective: Primary intraocular lymphoma, a non-Hodgkin's lymphoma, is a primary central nervous system lymphoma (PCNSL). Diagnosis is usuall y made by identifying malignant, large B lymphocytes in the vitreous, eye, brain, and cerebral spinal fluid; however, these cells ave few, f riable, and difficult to recognize. Recently, clonal heavy chain immun oglobulin (IgH) gene rearrangement and bcl-2 gene translocation have b een reported in systemic B-cell lymphoma and are used for the detectio n of malignant cells and in making a diagnosis. The authors investigat ed the molecular changes in three eyes and a chorioretinal biopsy spec imen of four patients with PCNSL. Design: Human tissue study. Material s: Five ocular specimens of PCNSL were collected. Intervention: The fi rst patient had a diagnostic enucleation of the left eye. The second p atient underwent diagnostic chorioretinal biopsy. In the third case, a pair of autopsied eyes with reactive lymphoplasmacytic infiltrates of a patient with acquired immune deficiency syndrome (AIDS) were studie d. In the fourth case, an enucleated eye of a patient with AIDS-associ ated lymphoma was sampled. Main Outcome Measures: The bcl-2 and IgH ge nes of the lymphoma cells from routine, paraffin-embedded, formaldehyd e-fixed, or frozen histologic tissue sections were analyzed using micr odissection and polymerase chain reaction (PCR) technique. Results: Ly mphoma cells obtained from the above four cases showed IgH rearrangeme nt gene in the third framework of the V-H region. Bcl-2-associated tra nslocation also was detected in three cases (cases 1, 2, and 4). Concl usion: Rearrangement of the IgH gene can serve as a molecular marker f or PCNSL. Microdissection allows for procurement and analysis of speci fic, selected, minute cell populations that are obtained from histolog ic sections of the complex, heterogeneous tissue. Translocation of IgH and bcl-2, the apoptotic ''survival'' signal and proto-oncogene, coul d contribute to the pathogenesis of PCNSL. The combination of microdis section and PCR is a powerful tool for studies of small lesions and ce ll populations and for understanding disease mechanisms.