Acoustic neuroma growth: a systematic review of the evidence.
OBJECTIVE
To undertake a systematic review of the literature on acoustic neuroma growth. Predictors of growth were also explored.


METHODS
A comprehensive search was conducted to identify the relevant literature. The search yielded 2,455 papers. All titles were reviewed by 2 of the authors, and finally, 41 papers were found reporting data pertinent to growth.


RESULTS
The percentage of acoustic neuromas exhibiting growth ranges widely from 18 to 73%. The percentage of tumors reported not to grow for some years after diagnosis ranges from 9 to 75%. Some (usually less than 10%, but up to 22%) may get smaller. No reliable predictors of growth have been identified. The mean growth rate for all tumors varies between 1 and 2 mm/yr, and for only those that grow, between 2 and 4 mm/yr. However, there are cases with significant regression or exceptional growth (exceeding 18 mm/yr). There are various patterns of growth, and a tumor that shows growth may stop doing so and vice versa. Finally, some tumors that have been stable for many years can exhibit tumor growth.


CONCLUSIONS
The growth pattern of acoustic neuromas is variable and incompletely understood. As much as 75% of tumors have been reported to show no growth, supporting a "wait and rescan" policy in many patients, although there are no reliable predictors of tumor behavior, and some tumors may grow rapidly. Primary longitudinal studies are needed to better define the natural history and limit unnecessary interventions.
Nikolopoulos
Thomas P
TP
2nd Department of Otorhinolaryngology, Athens University, Athens, Greece. Thomas.Nikolopoulos@Nottingham.ac.uk
Fortnum
Heather
H
O'Donoghue
Gerard
G
Baguley
David
D
D006801:Humans; D009464:Neuroma, Acoustic / Q000473:pathology*