select c.name as 'colname'
from sys.tables t , sys.columns c
where t.object_id = c.object_id and t.name like '%tableA%'
except
select c.name as 'colname'
from sys.tables t , sys.columns c
where t.object_id = c.object_id and t.name like '%tableB%'
-----------------------------------------------------------------------------------------
select c.name as 'colname'
from sys.tables t , sys.columns c
where t.object_id = c.object_id and t.name like '%TableB%'
except
select c.name as 'colname'
from sys.tables t , sys.columns c
where t.object_id = c.object_id and t.name like '%TableA%'
Please execute above queries together to know the differences