PRIMARY CEREBRAL FIBROSARCOMAS - CLINICOPATHOLOGICAL STUDY AND REVIEWOF THE LITERATURE

Background. Primary of the brain and meninges are uncommon tumors. Inf ormation regarding optimum treatment is limited due to their rarity, a nd the best form of therapy is not yet known. Methods. Nine patients b etween the ages of 22 and 61 years with primary fibrosarcomas confined to the brain and meninges were studied clinicopathologically. Tumors were superficially located in five patients and intracerebrally or dee p in four patients. Treatment consisted of maximum feasible surgical r esection (seven patients, gross total; one, subtotal; one, no surgery before death) and radiation therapy (45-60 Gy conventional fractionati on) in eight of nine patients. Results. Fibrosarcomas were moderate or high grade in seven of nine patients (78%). Immunohistochemical react ions with antisera to glial fibrillary acid protein (GFAP), cytokerati n, vimentin, desmin, and S-100 demonstrated vimentin positivity in fiv e of nine patients and cytokeratin positivity in two of nine patients. Individual GFAP-positive cells were seen in two cases, thought to rep resent trapped reactive astrocytes. None were S-100-positive or desmin -positive. Eight patients have died, with a median survival time of 7. 5 months (range, 1 day-96 months). Local recurrence developed in eight patients and distant recurrence in six patients. Systemic metastases developed in four patients (50%) and meningeal seeding in four patient s (50%). Longer survival was observed in superficially located tumors (range, 7.5 months-96 months) compared with intracerebral tumors (rang e, 1 day-9 months). Conclusions. Primary fibrosarcomas of the brain ar e uncommon tumors, usually of high histologic grade, with a high rate of local recurrence. Their propensity for meningeal and distant relaps e distinguishes them from tumors of glial origin. Immunohistochemistry is of limited diagnostic value, although it may facilitate exclusion of other diagnoses. Because the prognosis after conventional surgery w ith 50-60 Gy external beam radiation therapy is relatively poor, the a uthors recommend more aggressive therapy with maximal feasible resecti on followed by external beam radiation therapy to doses of 64-66 Gy. W hen effective chemotherapy is established for soft tissue sarcomas of the extremities, this should be evaluated in view of the high incidenc e of distant metastases.