gms | German Medical Science

Objective: Diagnosis of primary central nervous system lymphoma (PCNSL) is usually confirmed by brain biopsy and subsequent neuropathological work-up. In contrast to treatment of other brain tumors, efforts at resection are discouraged. 5-aminolevulinic acid-induced fluorescence (5-ALA) has been established for diagnostic and therapeutic purposes in glioma treatment for the last few years and discussed for use in other cranial tumors. But its role in diagnosis and treatment of PCNSL is still elusive. So far, there are only few case reports which demonstrate fluorescence during open biopsy or resection.

Method: This retrospective study includes clinical, MRI, pathological and surgical data of subjects with PCNSL at two University hospitals within the last 4 years. Therefore, we retrospectively analysed data of about 2500 patients undergoing surgical treatment for resection because of mass effect and suspected cerebral glioma. Pre-operatively, all patients received 5-ALA for fluorescence guided resection.

Results: Our study contains 12 subjects with complete clinical, MRI, pathological and surgical data aged 47 to 79 with PCNSL. This number of patients was collected from 2500 patients that were surgically treated in the context of suspected glioma with mass effect. In all subjects with PCNSL pathological work-up revealed malignant B-cell lymphoma with morphological features of diffuse large B-cell lymphoma (DLBCL). 10 of 12 patients with PCNSL showed a clear fluorescence induced by 5-ALA. Beside surgical resection to reduce mass effect, patients were usually treated by high-dose methotrexate-based chemotherapy regimens as first-line therapy according to their histopathological diagnosis and oncological recommendation.

Conclusions: After being biopsied, PCNSL is usually thought to be treated by systemic chemotherapy with or without whole brain radiotherapy. However, when compared with other lymphoma entities the outcome is still unsatisfactory. Interestingly, the traditional view that the extent of surgical resection has no prognostic impact on this disease has been challenged, recently. In glioma patients the use of 5-ALA is known to be associated with increased extent of resection and survival benefit. In this context our data suggest that the use of 5-ALA in PCNSL patients might be a promising tool for new diagnostic and therapeutic approaches, even in a way for photodynamic therapy in combination of 5-ALA.