Primary Intracranial Malignant Lymphoma

Abstract

Nine cases of primary intracranial malignant lymphoma, which accounts for 3.3% of all intracranial tumors seen in the authors' institution, were studied in terms of diagnostic computed tomographic (CT) features, the tumors' histologic appearance, treatment, post-treatment blood immunologic and cerebrospinal fluid (CSF) characteristics, and outcome. The patients were seven males and two females aged 42 to 67 years. Their chief signs and symptoms on admission were intracranial hypertension, focal signs, and disturbance of consciousness. CT, which proved the most useful preoperative diagnostic technique, demonstrated multiple lesions in seven cases and, in all cases, regions of isodensity or slight high density that were enhanced by contrast medium. According to the patterns of enhancement, the tumors were classed as diffuse (three cases) or nodular (six cases). The former is considered typical of malignant lymphoma, whereas the latter type was sometimes indistinguishable from metastatic tumor and meningioma. At surgery, one patient underwent radical tumor excision, two partial removal, and six biopsy only. Histologic examination revealed one tumor to be of the diffuse small cell type, three of the medium cell type, and five of the large cell type (Lymphoma Study Group classification). Of seven tumors in which lymphocytes were examined by peroxidase-antiperoxidase staining, four were of the B cell type. Postoperatively, whole brain irradiation with 29 to 46 Gy was followed by local irradiation with 15 to 50 Gy. If the tumor persisted, one of three chemotherapies was administered. In one case, methotrexate was given intrathecally. Seven patients were divided into two groups: long remission (three) and recurrence (four). These two groups were compared in terms of serum immunoglobulin levels, T and B cell ratios, CSF characteristics, CT features, tumor cell type, and treatment. No clear differences were found.