All kinds of ideas are possible in the Italian Opening, but the combination of a4 with Be3 produces a very rare position here.
1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1c4  3... g8f6  4. d2d3  4... f8c5  5. e1g1  5... e8g8  6. a2a4  6... d7d6 