Purpose: Primary intraocular lymphoma (PIOL) is an uncommon non-Hodgkin lymphoma and is usually of B-cell type. Intraocular T-cell or T/NK-cell lymphomas are extremely rare and mostly represent a secondary manifestation of either a cutaneous or a systemic lymphoma. The aim of the current paper is to report the clinical, histopathological and molecular biological findings of a PIOL of T-cell type.
Methods: Conventional cytological and immunocytological examination of vitrectomy specimens. Conventional histology, immunohistochemistry and polymerase chain reaction (PCR) for the detection of immunoglobulin heavy chain (IgH) and T-cell-receptor gamma (TCR-gamma) gene rearrangement, GeneScan analysis, and DNA sequencing were performed on the chorioretinal biopsy.
Results: Cytology of the right vitreous aspirate revealed a moderate cellular infiltrate consisting of medium-sized T-cells with pleomorphic nuclei. Similar atypical lymphocytes were seen in the partially necrotic chorioretinal biopsy. These lymphocytes expressed CD3, CD4, betaF1 and CD30, with a growth fraction of 90%. TCR-gamma-PCR, GeneScan analysis and DNA sequencing demonstrated a monoclonal amplification product within the expected range. In contrast, IgH-PCR revealed oligoclonal amplificates. The patient was treated with low-dose radiotherapy (total 45 Gy), and was in complete remission at final follow-up.
Conclusion: A rare PIOL of T-cell type was diagnosed on the basis of vitreous aspiration and chorioretinal biopsy. In addition to conventional cytology and immunocytology, the utilisation of gene rearrangement studies on vitreous or chorioretinal biopsies increases the chances of diagnosing or excluding a PIOL of either B-cell or T-cell type. Despite its rarity, ophthalmic pathologists should always consider the diagnosis of T-PIOL when reviewing vitreous samples.