Good morning everyone. I am going to talk about the relationship between hyperostosis and bone invasionin meningioma. And how it affects the management.
Association between meningioma and hyperostosis is well established.The incidence of hyperostosis ranges between 25 and 50% in various series
The cause of hyperostosis still is a matter of debate. Some believe it occurs as a reactionary change to meningioma. While others think it to be secondary to tumor invasion into the bone. The common practice today is to drill the hyperostotic bone and place the bone flap back.
The aim of this study was to assesswhether bony changes seen in meningioma can be attributed to tumor invasion and whether leaving the bone flap in situ might be same as leaving a part of the tumor behind.
Therefore, we conducted a prospective study over a period of 10 months, in which we enrolled all the patients with a preoperative diagnosis of intracranial meningioma, who underwent surgery at our institute.
Only those cases that were confirmed as meningioma on the histopathology were included.We excluded any case in which a bone biopsy was not available. ???planumsphenoidalemeningioma???
The Preoperative imaging was individually studied by two neurosurgeons to assess for bony thickening. Hyperostosis was said to be present when there was consensus among the two. The cases were classified according to location.
This is an example of a case of left frontal convexity meningioma, which reveals hyperostosis of the overlying bone.
This is a case of left lateral sphenoid wing meningioma, in which the overlying bone does not show any thickening.
During the surgery, a piece of bone was sent for pathological evaluation. In cases showing hyperostosis, this bone was taken from the hyperostotic area.While in the remaining cases, bone sampling was done from bone in contact with the dural attachment of the tumor
The features assessed on histopathology were
Of the 49 cases that were initially enrolled, 9 were found to be tumors other than meningioma on histopathology and therefore exluded.The remaining 40 cases formed the study group.
Of these 40 cases, 22 were females and 18 were males.
Most of the patients were in 30-60 years’ age group. It is noteworthy that 35 of the 40 patients were younger than 60 years of age.
On radiology, hyperostosis was seen in 30 patients, i.e. 75% of the cases.
The convexity and skull base meningiomas showed a higher incidence of hyperostosis, that is 83 %.
On histopathology, transitional meningioma was most common.
36 out of 40 cases belonged to WHO grade I, while there were 4 WHO grade II tumors.
On histopathology, tumor invasion into the bone was seen in 8 patients, i.e. 20% of the cases.
Of the 30 cases showing hyperostosis, bony invasion by the tumor was seen in 7 cases. Of the 10 cases not showing hyperostosis, one case showed tumor invasion into the bone.
Looking at these figures the other way around. Of the eight cases
Convexitymeninigoma had the highest incidence of bone invasion by the tumor, i.e. 33%. There was no significant correlation between tumor location and tumor invasion into the bone.
Three of the eight cases of meningothelialmeningiomas showed tumor invasion into the bone.Where as, bone was invaded by the tumor in five of the 19 tranitionalmeningiomas.The other histological types did not show tumor invasion into the bone.
This is a case of anterior 1/3 falcinemeningioma, which reveals overlying hyperostosis. On histopathology, it was found to be a meningothelialmeningioma. The bone biopsy revealed tumor invasion into the bone.
This is a case of right lateral sphenoid wing mengingoma, which shows thickening of the overlying bone. The biopsy of the bonerevealed tumor invasion between the bony trabeculaealongwith destruction. Here is a high power view of the same. (transitional)
This case of right frontal convexity meningioma had no overlying hyperostosis. However, on histopathology, it revealed tumor invasion into the bone.(transitional meningioma)
To quote Harvey Cushing,” There is nothing more gratifying in the whole realm of surgery than the successful removal of a meninigoma with subsequent perfect functional recovery.” These words are as true today as they were 90 years back.
Simpson defined grade I excision of meningioma as…However, the question arises, “ what constitutes abnormal bone??” In our opinion, any bone which has been infiltrated by the tumor cells should be labeled as abnormal.
Also,intraoperativehistopathological evaluation of the bone is not feasible by frozen section.Bone can not be cut on a freezing microtome before decalcification.
. . . As it might be infiltrated by the tumor cells
In our study, the probability of sampling error can not be ruled out. However, if there were sampling error, the actual incidence of bone invasion will be higher than what has been reported here.
Thank you very much for your kind attention.
Significance of hyperostosis in meningiomas
The Significance of Hyperostosis in Intrancranial Meningioma and How It Affects the Management Nishant Goyal, Deepak Agrawal Department of NeurosurgeryAll India Institute of Medical Sciences, New Delhi, India
IntroductionO Association between meningioma and hyperostosis O Hyperostosis is seen in 25-49 % of intracranial meningiomas* •Cushing H. The cranial hyperostoses produced by meningeal endotheliomas. Arch Neurol Psychiatry 1922; 8: 139-154 •Cushing H, Eisenhardt L. Meningiomas: Their Classification, Regional Behavior, Life History and Surgical End Results. Springfield, Charles C Thomas, 1938. • Frazier CH, Alpers BJ. Meningeal fibroblastomas of the cerebrum. Arch Neurol Psychiatry 1933; 29: 935–989. • Spiller WG. Hemicraniosis and cure of brain tumor by operation. JAMA 1907; 49: 2059–2065.
IntroductionO Cause of hyperostosis still a matter of debate O Occurs as a reactionary change to meningioma O Due to tumor invasion into the boneO Common practice is to drill the hyperostotic bone & place the bone flap back
HypothesisO Bone changes seen in meningioma can be attributed to tumor invasionO Leaving the bone flap in situ may be same as leaving a part of the tumor behind
MethodsO Study design: ProspectiveO Study period : October 2010- July 2011 (10 months)O Consecutive patients with a preoperative diagnosis of intracranial meningioma who underwent surgery
MethodsO Inclusion criteria- O All cases of intracranial meningioma (on histopathology) who were operated in our institute during study periodO Exclusion criteria- O Intracranial tumors other than meningioma (on histopathology) O Tumors in which bone biopsy was not available
Methods: RadiologyO Preoperative MR imaging and CT scans O Examined individually by two neurosurgeons to assess for bone thickening overlying the tumor O Present when there was consensus among the twoO The cases of meningioma were classified according to location
Methods: Radiology No HyperostosisMRI scan CT scan Bony cuts
Methods Patients with preoperative diagnosis of intracranial meningioma Hyperostosis Hyperostosis present absentBone sampling done Bone sampling done from from hyperostotic bone in contact with the region dural attachment of the tumor
Methods: HistopathologyO Tumor tissue was processed as is routine for histopathological examinationO Bone was decalcified and then processedO Hematoxylin and eosin stained slides of tumor tissue and bone sample were examined by two neuropathologists
Methods: Histopathology Features assessed on histopathology: WHO Grade and Type of meningioma MIB-1 labeling index (MIB-1 LI) Presence of tumor invasion into the bone
Results Total number of cases with preoperative diagnosis of intracranial meningioma (n= 49) Histopathological examinationNon meningioma (n=9) Intracranial (Excluded) meningioma (n=40) Study group
Results (n=40) 192015 810 6 4 5 2 1 0 Type of meningioma (On histopathology)
Results (n=40) WHO GradeWHO Grade I WHO Grade II 36 (90%) 4 (10%)
Results (n=40)O MIB- 1 labeling index O Range= 1 to 15 O Mean= 3.5
Results (n=40)Tumor Invasion Into The Bone On Histology Absent 32 (80%) Present 8 (20%)
Meningiomas (n=40) Radiological evidence of hyperostosis Hyperostosis Hyperostosis present (n= 30) absent (n= 10) Histological evaluation of bone Bone No bone Bone No boneinvasion invasion invasion invasion (n=7) (n=23) (n=1) (n=9)
Results (n=40)O Of the eight cases showing tumor invasion into the bone on histology O Seven had hyperostosis on radiology O One without hyperostosis
Results (n=40)Location Number Tumor invasion of cases presentConvexity 12 4 (33.3%)Parasagittal & peritorcular, falcine 16 2 (12.5%)and tentorialSkull base 12 2 (16.7%)Total 40 8 (20%)
Results (n=40)O Tumor invasion into the bone O Three cases of meningothelial meningiomas (3 out of 8 cases; 37.5%) O Five cases of transitional meningiomas (5 out of 19 cases; 26.3%)O Tumor invasion into the bone did not show any significant correlation with WHO grade, type and MIB-1 labeling index in our study (p>0.05)
DiscussionO A number of studies have upheld the principle that clinical success in meningioma surgery is related to the extent of resection Bikmaz K, Mrak B, Al-Mefty O. Management of bone-invasive, hyperostotic sphenoid wing meningiomas. J Neurosurg 2007; 107: 905–912 Jääskeläinen J. Seemingly complete removal of histologically benign intracranial meningioma: Late recurrence rate and factors predicting recurrence in 657 patients-A multivariate analysis. Surg Neurol 1986; 26: 461-469 Al-Mefty O, Kadri PA, Pravdenkova S, Sawyer JR, Stangeby C, Husain M. Malignant progression in meningioma: documentation of a series and analysis of cytogenetic findings. J Neurosurg 2004; 101: 210–218
DiscussionO In 1957, Simpson elaborately described the importance of degree of resection in preventing recurrence in meningioma Simpson Excision Recurrence at 10 yrs Grade I 9% II 19% III 29% IV 40% Simpson D. The recurrence of intracranial meningiomas after surgical treatment. J Neurol Neurosurg Psychiatry 1957; 20: 22-39.
DiscussionO Simpson Grade I excision of meningioma O Macroscopically complete removal of tumor with excision of its dural attachment and any abnormal boneO What is abnormal bone?
DiscussionO Our study shows that it is not possible to predict which patients are likely to show bone invasion on the basis of O Preoperative radiology, as invasion can occur without hyperostosis on radiologyO Intra-operative pathological evaluation of bone is not feasible by frozen section examination
DiscussionO Therefore, in order to achieve better Simpson grade of tumor excision one should remove as much bone in contact with the tumor as possible in all cases
LimitationO The possibility of sampling error can not be completely ruled outO The actual incidence of bone invasion is likely to be higher than in our study
ConclusionO A significant number of patients (23.5% in our study) with radiological hyperostosis have tumor invasion into the boneO However, the absence of hyperostosis does not mean the absence of tumor invasion
ConclusionO We recommend that one should remove the bone (flap) whenever possible in order to achieve complete excision of intracranial meningioma in close proximity to bone and use synthetic material to cover the defect.