Radiation-induced meningiomas: clinical, pathological, cytokinetic, and cytogenetic characteristics.
OBJECTIVE
Radiation-induced meningiomas are known to occur after high- and low-dose cranial radiation therapy. The goal of this study was to discern the distinguishing findings and characteristics of radiation-induced meningiomas.


METHODS
The records of 16 patients (seven men and nine women) who fulfilled the criteria for radiation-induced meningiomas were retrospectively reviewed. Clinical, histopathological, cytokinetic, and cytogenetic findings as well as the patients' outcome were analyzed. The mean age of the patients was 38.8 years and the mean tumor latency was 26.5 years. Five patients had multiple meningiomas in the irradiated field. The recurrence rate was 100% after the initial resection; 62% of patients had a second recurrence and 17% had a third recurrence. Thirty-eight percent of patients had atypical or malignant histopathological findings. The presence of progesterone receptors and low proliferation indices in these patients did not correlate with benign tumor behavior. Cytogenetic analysis showed multiple clonal aberrations in all tumors studied. The most frequent aberrations were found on chromosomes 1p, 6q, and 22. Derivative, lost, or additional chromosome 1p was found in 89% of cases and loss or deletion on chromosome 6 was found in 67%.


CONCLUSIONS
The age of patients at presentation with meningioma and the latency period of radiation-induced meningiomas are dose related. These tumors are more aggressive and are certain to recur, have a higher histopathological grade, and are associated with complex cytogenetic aberrations particularly involving 1p and 6q.
Al-Mefty
Ossama
O
University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA. aekeeland@uams.edu
Topsakal
Cahide
C
Pravdenkova
Svetlana
S
Sawyer
Jeffrey R
JR
Harrison
Michael J
MJ
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008577:Meningeal Neoplasms / Q000209:etiology* / Q000235:genetics / Q000473:pathology*; D008579:Meningioma / Q000209:etiology* / Q000235:genetics / Q000473:pathology*; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000235:genetics / Q000473:pathology*; D011379:Prognosis; D011980:Receptors, Progesterone / Q000032:analysis; D012189:Retrospective Studies; D013997:Time Factors
D011980:Receptors, Progesterone