Since acoustic neuromas are benign, often slow-growing tumors, careful observation over a period of time may be appropriate for some patients. When a small tumor is discovered in a patient, observation to study the growth rate of the tumor may be indicated if acute symptoms are not present. An MRI scan of the tumor and surrounding region must be performed periodically to determine if there is any significant change in the size of the tumor. The most common MRI protocol is to obtain an MRI six months after the first MRI, then nine months after the second MRI and then yearly for five years after the third MRI. After five years, the MRI may be extended to every 2 - 3 years. If the tumor does not grow, and if debilitating symptoms do not occur, observation is continued. If the tumor increases in size, treatment may be recommended at any time during this observation period.