Acoustic Schwannoma

✓ The authors report the case of a young man suffering from neurofibromatosis type 2 (NF2) who harbored bilateral acoustic schwannomas and a parasellar meningioma. Neuroimaging studies performed during a 4-year follow-up period showed that the bilateral schwannomas had grown very little and at similar rates. However, after the meningioma had infiltrated the tentorium and approached the ipsilateral schwannoma at the incisura, both Schwann cell tumors started to grow rapidly, particularly the one adjacent to the meningioma, of which the percentage of annual growth rate increased by approximately a factor of 102. At the same time, magnetic resonance imaging showed that this tumor also changed its features. During surgery, the acoustic schwannoma was firmly adherent to both meningioma and tentorium. Histological examination revealed meningotheliomatous cells in the schwannoma adjacent to the meningioma. Antiphosphotyrosine immunoblotting of PC12 cells was compatible with the presence of an epidermal growth factor (EGF)—like molecule in the cerebrospinal fluid (CSF) of the patient. This factor was not detected in the CSF of five other NF2 patients, two of whom bore associated bilateral acoustic schwannomas and meningioma in remote locations. It is hypothesized that the meningotheliomatous cells infiltrating the schwannoma triggered an autocrine/paracrine growth—stimulatory mechanism that involved an EGF-like factor.

Download Full-text

Planning and Dosimetric Study of Volumetric Modulated Arc Based Hypofractionated Stereotactic Radiotherapy for Acoustic Schwannoma - 6MV Flattening Filter Free Photon Beam

Asian Pacific Journal of Cancer Prevention ◽

10.7314/apjcp.2015.16.12.5019 ◽

2015 ◽

Vol 16 (12) ◽

pp. 5019-5024 ◽

Cited By ~ 2

Author(s):

Shanmugam Thirumalai Swamy ◽

Chandrasekaran Anu Radha ◽

Gandhi Arun ◽

Murugesan Kathirvel ◽

Sai Subramanian

Keyword(s):

Stereotactic Radiotherapy ◽

Photon Beam ◽

Hypofractionated Stereotactic Radiotherapy ◽

Flattening Filter Free ◽

Dosimetric Study ◽

Flattening Filter ◽

Acoustic Schwannoma

Download Full-text

Tc-99m MIBI Brain SPECT of an Acoustic Schwannoma

Clinical Nuclear Medicine ◽

10.1097/00003072-199402000-00018 ◽

1994 ◽

Vol 19 (2) ◽

pp. 152-154 ◽

Cited By ~ 4

Author(s):

CHAN H. PARK ◽

SUNG M. KIM ◽

JAMES ZHANG ◽

JACK R. McEWAN ◽

CHARLES INTENZO

Keyword(s):

Brain Spect ◽

Acoustic Schwannoma

Download Full-text

Frameless Hypo-fractionated Radiosurgery For Koos Grade 4 Acoustic Schwannoma

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/j.ijrobp.2020.07.2059 ◽

2020 ◽

Vol 108 (3) ◽

pp. e693-e694

Author(s):

V. Shankar ◽

V. Sai Shreya ◽

U. Andar ◽

C.E. Deopujari ◽

H. Vyas ◽

...

Keyword(s):

Acoustic Schwannoma

Download Full-text

Principles and Practice of Stereotactic Radiosurgery ◽

10.1007/978-0-387-71070-9_23 ◽

2008 ◽

pp. 275-281

Author(s):

William M. Mendenhall ◽

Robert J. Amdur ◽

Robert S. Malyapa ◽

William A. Friedman

Keyword(s):

Acoustic Schwannoma

Download Full-text

Dosimetric comparison of Linac-based (BrainLAB®) and robotic radiosurgery (CyberKnife®) stereotactic system plans for acoustic schwannoma

Journal of Neuro-Oncology ◽

10.1007/s11060-011-0703-5 ◽

2011 ◽

Vol 106 (3) ◽

pp. 637-642 ◽

Cited By ~ 15

Author(s):

Debnarayan Dutta ◽

S. Balaji Subramanian ◽

V. Murli ◽

H. Sudahar ◽

P. G. Gopalakrishna Kurup ◽

...

Keyword(s):

Dosimetric Comparison ◽

Robotic Radiosurgery ◽

Stereotactic System ◽

Acoustic Schwannoma

Download Full-text

Criteria for hearing preservation in acoustic schwannoma surgery: The concept of useful hearing

The Journal of Laryngology & Otology ◽

10.1017/s002221510011998x ◽

1992 ◽

Vol 106 (6) ◽

pp. 500-503 ◽

Cited By ~ 11

Author(s):

A. E. Hinton ◽

R. T. Ramsden ◽

R. H. Lye ◽

J. E. M. Dutton

Keyword(s):

Pure Tone ◽

Tumour Size ◽

Hearing Preservation ◽

Discrimination Score ◽

Speech Discrimination ◽

Average Difference ◽

Pure Tone Audiogram ◽

Speech Discrimination Score ◽

Acoustic Schwannoma

AbstractIn the quest for hearing preservation in patients with acoustic schwannomas it is essential that surgeons do not lose sight of the concept of ‘useful’ hearing. There is an important difference between hearing preservation which pleases the surgeon and that which will be appreciated by the patient.Tumour size, pure tone audiogram average differences between ears and speech discrimination scores have been recorded in a series of 114 patients with unilateral acoustic schwannomas. Criteria for useful hearing are presented in terms of pure tone audiogram average difference and speech discrimination scores.There were 11 patients (10 per cent) with a speech discrimination score of 50 per cent or more, a pure tone audiogram average difference of 30 dB or better and a tumour size of no more than 2 cm. Only one patient (0.9 per cent) had a speech discrimination score of 50 per cent or more, a pure tone audiogram average difference of 20 dB or better and a tumour size of no more than 1 cm.It is concluded that hearing preservation techniques may be applicable to between 1 and 10 per cent of patients with unilateral acoustic schwannomas.

Download Full-text