Primary cerebral fibrosarcomas. Clinicopathologic study and review of the literature.

BACKGROUND

Primary of the brain and meninges are uncommon tumors. Information regarding optimum treatment is limited due to their rarity, and the best form of therapy is not yet known.

METHODS

Nine patients between 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 deep in four patients. Treatment consisted of maximum feasible surgical resection (seven patients, gross total; one, subtotal; one, no surgery before death) and radiation therapy (45-60 Gy conventional fractionation) in eight of nine patients.

RESULTS

Fibrosarcomas were moderate or high grade in seven of nine patients (78%). Immunohistochemical reactions with antisera to glial fibrillary acid protein (GFAP), cytokeratin, vimentin, desmin, and S-100 demonstrated vimentin positivity in five of nine patients and cytokeratin positivity in two of nine patients. Individual GFAP-positive cells were seen in two cases, thought to represent 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 patients (50%). Longer survival was observed in superficially located tumors (range, 7.5 months-96 months) compared with intracerebral tumors (range, 1 day-9 months).

CONCLUSIONS

Primary fibrosarcomas of the brain are uncommon tumors, usually of high histologic grade, with a high rate of local recurrence. Their propensity for meningeal and distant relapse 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 with 50-60 Gy external beam radiation therapy is relatively poor, the authors recommend more aggressive therapy with maximal feasible resection followed by external beam radiation therapy to doses of 64-66 Gy. When effective chemotherapy is established for soft tissue sarcomas of the extremities, this should be evaluated in view of the high incidence of distant metastases.