I'm only aware of one current-production motherboard which meets that criteria, and even then it is a bit older - http://www.newegg.com/Product/Product.aspx?Item=N82E16813157...

You could use this in the mITX case of your choice based on the other hardware you need to fit.

Intel previously made one similar, but it has been EOL'd. http://ark.intel.com/products/67346/

Very narrow use case, indeed. :-/