THE SIGNIFICANCE OF LACK OF MR CONTRAST ENHANCEMENT OF SUPRATENTORIALBRAIN-TUMORS IN ADULTS - HISTOPATHOLOGICAL EVALUATION OF A SERIES

BACKGROUND To correlate magnetic resonance imaging (MRI) findings of n on-enhancement of supratentorial brain neoplasms in adults with histop athologic findings. METHODS Forty adult patients whose preoperative MR I studies demonstrated a non-enhancing supratentorial brain neoplasm w ere identified retrospectively. Biopsy material for all patients was t hen reviewed by a board-certified neuropathologist, RESULTS Histopatho logic examination identified 24 (60%) low-grade gliomas: 4 (10%) low-g rade astrocytomas, 10 (25%) low-grade gliomas (not further classified) , 8 (20%) low-grade oligodendrogliomas, and 2 (5%) law-grade mixed oli goastrocytomas. However, 16 (40%) nonenhancing lesions were classified as anaplastic gliomas: 12 (30%) anaplastic astrocytomas, 1 (2.5%) ana plastic mixed oligoastrocytoma, 1 (2.5%) anaplastic oligodendroglioma, and 2 (5%) anaplastic infiltrating gliomas of indeterminate subtype. CONCLUSION Non-enhancement of supratentorial brain neoplasms in adults does not equate with low-grade malignancy, This fact should be taken into account when biopsy and treatment are being planned in patients w ith nonenhancing brain tumors. More aggressive and/or surgical therapy might be indicated for such lesions, particularly those in the nondom inant hemisphere or nonmotor areas. (C) 1998 by Elsevier Science Inc.