Spring Surprise Salad

13 1/4-ounce can crushed pineapple (2 cups) drained; reserve juice
3-ounce package lemon-flavored gelatin
1 cup boiling water
2/3 cup reserved pineapple juice (add enough water to make 2/3 cup)
2 Tbsp. lemon juice
1/2 cup shredded cucumber
1/2 cup shredded American Cheese
1/4 cup mayonnaise

Dissolve gelatin in boiling water. Stir in pineapple juice and lemon juice. Chill until partially set. Whip gelatin until very light. Fold in crushed pineapple, cucumber, cheese, and mayonnaise. Turn into 9-inch square pan or 5-cup ring mold. Chill until firm.