Without photos it's really hard to make a guess.

The link below is to a pdf showing the majority of problems you're likely to see in mature fruit. See if anything there looks like what you've got.

Here is a link that might be useful: U of FL on tomato problems

Thank you SO much! yes, I found the answer in this pdf. VERY valuable and I am so glad you sent me this! Will be keeping to refer to this forever!

Westy

You're welcome! I'm glad it helped. IFAS (the Institute of Food and Agriculture) at U of F has many good publications on various pest/disease problems. For info specific to your part of the country, so does the U of Colorado. Both sites are worth checking out.