1. Prepare salsa.
2. Pick crabmeat, removing any bits of shell.
3. Whisk together mayonnaise and next 3 ingredients in a large bowl. Gently stir in crabmeat, panko, and next 2 ingredients. Shape mixture into 16 (2-inch) cakes (about 1/4 cup each). Cover and chill 1 to 4 hours.
4. Melt 2 Tbsp. butter in a large nonstick skillet over medium heat. Add 8 crab cakes; cook 2 to 3 minutes on each side or until browned. Repeat with remaining butter and crab cakes. Serve with Pineapple-Cucumber Salsa and lime wedges.