Tourist VISA Expiration

I am a US citizen.  In 2012 I was studying in Buenos Aires and got a VISA at that time to go to Brazil for a short trip.  I am going back to Brazil next month for World Cup and am trying to figure out if my VISA is still valid.  At the time, I thought they said it was good for multiple entries over 10 years but now as I look closely at the VISA, there is not any actual expiration date on the VISA.  There are stamps for entry and exit in May of 2012.  The VISA has my picture on it.  It say it is a multiple entry.  Type is Vitur.  Duration of stay: 90 days.  At bottom it says:  VISA valid for 90 days from first day of entry into Brazil.  Maximum stay: 180 days.  Can you tell me how I would determine if it is still valid.
Thanks!

It was only recently that the Brazilian VITUR Tourist Visa for US citizens was extended to have a 10 year validity. The older visas (which you have) are valid only for 5 years. In fact, all VITUR visas are valid for 5 years unless otherwise stated on the document.

Cheers
William James Woodward, EB Experts Team

Thank you.  Given how busy the consulates are with all the world cup travel, I have had trouble getting anyone at the consulate to answer this question.  The VISA agencies have provided contradicting info. The Vancouver Consulate....they only who who has provided a response, said that unless the expiration date is actually listed on the VISA, it is only good for 90 days.  Can you tell me how I can validate or where the source info is that says all older Vitur Visas are for 5 years.

Really appreciate your assistance.

On a 5 or 10 year visa, you're granted a 90 day stay. It has nothing to do with the validity of the visa.

But is there a way by looking at the VISA to confirm it is a 5 or 10 year Visa.

http://www.passportvisasexpress.com/ima … l_visa.jpg

Thanks.  My Visa looks just like this except in the comment section instead of saying valid for 10 years from date of issue, mine says VISA valid for 90 days from first date of entry into Brazil.  So it looks like they did not give me a five year VISA but only a 90 day Visa.  So now I need to figure out how to get a new Visa in time.