RECURRENCE OF CRANIAL BASE MENINGIOMAS

OBJECTIVE: Long-term data on the natural history of traditionally trea ted cranial base meningiomas are necessary to judge the benefit of mod ern cranial base techniques for individual patients and to understand when nonradical surgery of a meningioma is in the interest of the pati ent. The only available means of obtaining such data is investigation of patients treated before the present surgical era. METHODS: The reco rds of 315 patients who were operated on at Karolinska Hospital betwee n January 1, 1947, and December 31, 1982, were reviewed. Of the patien ts, 10.8% died perioperatively and 9.7% died within 10 years. The rema ining patients were followed for 10 to 36 years (mean, 18 yr). RESULTS : The 5-year recurrence rate was 4% for patients undergoing radical su rgery (Grades 1 and 2) and 25 to 45% for patients undergoing Grade 3 o r 4 operations. Follow-up periods longer than 5 years revealed that 16 % of Grade 1 and 20% of Grade 2 patients had symptomatic recurrences, whereas a majority of Grade 4 and 5 patients showed symptomatic progre ssion. Forty-two of 69 patients who underwent Grade 4 or 5 operations died as a result of their tumors, usually within 10 years after the fi rst operation. No patients who underwent Grade 4 or 5 operations were free from symptomatic progression after 20 years. The tumor progressio n or recurrence was usually detected within the Ist 10 years, but late recurrences were seen less than or equal to 25 years after the operat ion. The worst outcome was found in medial sphenoid wing/clinoidal men ingiomas and in tumors invading the cavernous sinus. Subfrontal tumors showed unexpectedly high recurrence rates, with a mortality rate less than or equal to 14% in the late phase. CONCLUSION: The findings emph asized the necessity to plan the management of patients with cranial b ase meningiomas according to a 10- to 20-year perspective. Patients mu st be followed to evaluate the treatment results and to detect recurre nces. Nonradical surgery must be viewed as a temporizing or palliative measure; a continued search for means of radical tumor treatment is w arranted in these often surgically difficult tumors.