1. There is no substitute for direct examination and biopsy
2. The raised patch may be a patch of Leukoplakia
(white) or Erythroplakia
(red / tan) which are most probably related to tobacco use.
3. Leukoplakia or Erythroplakia is considered benign but a potential precancerous lesion with a risk of turning cancerous in 5 to 15% persons.
4. Stopping the irritative factor, such as tobacco in your case, lowers the risk. It is good to hear that you have quit. Usually, the Leukoplakia / Eruthroplakia stabilizes or reduces after the original irritation that caused it has been stopped.There are some other causes besides tobacco which can lead to other types of Leukoplakia / Erythroplakia.
5. One option for you is a brush biopsy with Oral CDX which you can easily arrange for.The other is a full biopsy followed by histopathological examination. Long term follow up is needed.