It was with great interest that we read the article titled “Malignant Transformation of Acoustic Neuroma/Vestibular Schwannoma 10 Years after Gamma Knife Stereotactic Radiosurgery” by Demetriades et al in the September 2010 issue of Skull Base.[1] We were surprised to see that the authors identified only 13 cases. We did a literature review and found 36 cases of malignant acoustic tumors. In two cases, the tumors have grown rapidly 7 years and 2 years consecutively and the patients passed away shortly without confirmation of the malignancy. There were nine reports that described malignancy in neurofibromatosis type 2 (NF2) patients, and interestingly, all of these nine patients had received stereotactic radiation as initial treatment for their tumor (Table [1]).[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Table 1 Summary of Reported Cases of Malignant Vestibular SchwannomaAuthorsAge/SexSideNF2PathologyPrevious IrradiationSurvivalDastur 1967238/MLNMelanotic schwannomaN8 moKudo 1983354/MRNMPNSTN1 moMiller 1986474/MN/AN/AMelanotic schwannomaNN/AHernanz-Schulman 198652/FN/ANMPNSTNN/ABest 1987624/FRNTritonN1.5 moMcLean 1990775/MRNMPNSTN2 moHan 1992847/FRNTritonN2 wkMaeda 1993938/MRNTritonN3 moMrak 19941040/MLNMPNSTN36 moEarls 19941177/MLNMelanotic schwannomaNN/ANorén 19981218/FRYTritonYN/AComey 19981350/MRNTritonY24 moThomsen 20001419/FRYSarcomaY12 moSaito 20001569/MLNMPNSTNN/ABaser 200016N/AN/AYMPNSTYN/ABaser 200016N/AN/AYMPNSTYN/ABaser 200016N/AN/AYMPNSTYN/AHanabusa 20011751/FRNSarcomaYAutopsyBari 20021828/FLYMPNSTY3 moShin 20021926/FRNMPNSTY10 moHo 20022014/FLYRapid growthY2 wkMcEvoy 20032122/MRYRapid growthY3 moWilkinson 20042253/MRNMPNSTYN/AKubo 20052351/MLNMPNSTYN/AMuracciole 20042461/FLNTritonYN/AMaire 200625N/AN/ANMPNSTYN/AGonzalez 20072643/FLNMPNSTN8 moChen 20082762/FLNMPNSTN4 moScheithauer 20092867/MRNMPNSTN1 moScheithauer 20092856/MRNMPNSTN2 moScheithauer 20092850/MLNMPNSTN36 moScheithauer 20092832/MLNMPNSTN3 moScheithauer 2009285/MLNMPNSTNN/AVan Rompaey 20092953/FRNMPNSTYAutopsyYang 20103074/MLNSarcomaY2 moDemetriades 2010137/MLNMPNSTY6 moL, left; MPNST, malignant peripheral nerve sheath tumor; N, no; N/A, not available; NF 2, neurofibromatosis type 2; R, right; Y, yes. It should also be noted that two of the cases identified by the authors referred to the same patient. In fact, Kudo and Matsumoto and colleagues have published the same case of malignant vestibular schwannoma twice: the first time in English and the second time in Japanese, 7 years later.[3][31] In addition, the experience from the National Centre for Stereotactic Radiotherapy in Sheffield showed not only one astrocytoma after gamma knife surgery for a cavernoma but also a new appearance of a glioblastoma multiforum in a patient 3 years after receiving radiotherapy for the treatment of his vestibular shwannoma.[32] We agree with the authors that long-term follow-up is mandatory after gamma knife treatment, because most of the malignant transformation appeared at least 5 years after the initial radiotherapy, and in one case, it appeared after 19 years.[25] Therefore, even if stereotactic radiotherapy is widely used for vestibular schwannoma treatment in patients with small tumor and good hearing, we think that this therapeutic modality should be avoided or at least used with caution in NF2 cases and young patients.
On "malignant transformation of acoustic neuroma/vestibular schwannoma 10 years after gamma knife stereotactic radiosurgery" (skull base 2010;20:381-388).
SANNA, Mario
2011-01-01
Abstract
It was with great interest that we read the article titled “Malignant Transformation of Acoustic Neuroma/Vestibular Schwannoma 10 Years after Gamma Knife Stereotactic Radiosurgery” by Demetriades et al in the September 2010 issue of Skull Base.[1] We were surprised to see that the authors identified only 13 cases. We did a literature review and found 36 cases of malignant acoustic tumors. In two cases, the tumors have grown rapidly 7 years and 2 years consecutively and the patients passed away shortly without confirmation of the malignancy. There were nine reports that described malignancy in neurofibromatosis type 2 (NF2) patients, and interestingly, all of these nine patients had received stereotactic radiation as initial treatment for their tumor (Table [1]).[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Table 1 Summary of Reported Cases of Malignant Vestibular SchwannomaAuthorsAge/SexSideNF2PathologyPrevious IrradiationSurvivalDastur 1967238/MLNMelanotic schwannomaN8 moKudo 1983354/MRNMPNSTN1 moMiller 1986474/MN/AN/AMelanotic schwannomaNN/AHernanz-Schulman 198652/FN/ANMPNSTNN/ABest 1987624/FRNTritonN1.5 moMcLean 1990775/MRNMPNSTN2 moHan 1992847/FRNTritonN2 wkMaeda 1993938/MRNTritonN3 moMrak 19941040/MLNMPNSTN36 moEarls 19941177/MLNMelanotic schwannomaNN/ANorén 19981218/FRYTritonYN/AComey 19981350/MRNTritonY24 moThomsen 20001419/FRYSarcomaY12 moSaito 20001569/MLNMPNSTNN/ABaser 200016N/AN/AYMPNSTYN/ABaser 200016N/AN/AYMPNSTYN/ABaser 200016N/AN/AYMPNSTYN/AHanabusa 20011751/FRNSarcomaYAutopsyBari 20021828/FLYMPNSTY3 moShin 20021926/FRNMPNSTY10 moHo 20022014/FLYRapid growthY2 wkMcEvoy 20032122/MRYRapid growthY3 moWilkinson 20042253/MRNMPNSTYN/AKubo 20052351/MLNMPNSTYN/AMuracciole 20042461/FLNTritonYN/AMaire 200625N/AN/ANMPNSTYN/AGonzalez 20072643/FLNMPNSTN8 moChen 20082762/FLNMPNSTN4 moScheithauer 20092867/MRNMPNSTN1 moScheithauer 20092856/MRNMPNSTN2 moScheithauer 20092850/MLNMPNSTN36 moScheithauer 20092832/MLNMPNSTN3 moScheithauer 2009285/MLNMPNSTNN/AVan Rompaey 20092953/FRNMPNSTYAutopsyYang 20103074/MLNSarcomaY2 moDemetriades 2010137/MLNMPNSTY6 moL, left; MPNST, malignant peripheral nerve sheath tumor; N, no; N/A, not available; NF 2, neurofibromatosis type 2; R, right; Y, yes. It should also be noted that two of the cases identified by the authors referred to the same patient. In fact, Kudo and Matsumoto and colleagues have published the same case of malignant vestibular schwannoma twice: the first time in English and the second time in Japanese, 7 years later.[3][31] In addition, the experience from the National Centre for Stereotactic Radiotherapy in Sheffield showed not only one astrocytoma after gamma knife surgery for a cavernoma but also a new appearance of a glioblastoma multiforum in a patient 3 years after receiving radiotherapy for the treatment of his vestibular shwannoma.[32] We agree with the authors that long-term follow-up is mandatory after gamma knife treatment, because most of the malignant transformation appeared at least 5 years after the initial radiotherapy, and in one case, it appeared after 19 years.[25] Therefore, even if stereotactic radiotherapy is widely used for vestibular schwannoma treatment in patients with small tumor and good hearing, we think that this therapeutic modality should be avoided or at least used with caution in NF2 cases and young patients.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
