Developments in the diagnosis and treatment of primary CNS lymphoma: A prospective series

Current experience with 12 patients studied prospectively suggests a new approach in the diagnosis and treatment of primary central nervous system (CNS) lymphoma, integrating the techniques of needle brain biopsy, immunohistochemicai staining for monoclonal antibody and chemotherapeutic drug delivery in association with blood‐brain barrier modification. Computed tomography (CT)‐guided needle biopsy of deep parenchymal lesions contributed to the diagnosis in six patients. Immunohistochemicai staining methods detected monoclonal immunoglobulins in those patients so tested. Following diagnosis, the patients have been treated with multi‐agent chemotherapy in conjunction with osmotic blood‐brain barrier modification (five without antecedent cranial irradiation) with an initial complete response rate by CT scan in nine patients, a median follow‐up of 19 months from diagnosis, and a 1‐year survival of 75%. This experience emphasizes the value of CT‐guided stereotaxic or CT‐guided needle biopsy, which limits the need for therapy without a diagnosis or the need for a major craniotomy in what are commonly deep, paraventricular lesions. Immunoperoxidase cytochemical stains can detect monoclonal immunoglobulin characteristic of CNS B‐cell malignant lymphomas and provide an important diagnostic aid when only modest quantities of tissue or cells are obtained. Finally, chemotherapy administered in conjunction with osmotic blood‐brain barrier modification results in a clinical response rate and survival that are at least as effective as radiotherapy as a primary therapeutic modality.