Conditionally call async function in Node

I have the following example code - the first part can result in an async call or not - either way it should continue. I cannot put the rest of the code within the async callback since it needs to run when condition is false. So how to do this?

if(condition) {
    someAsyncRequest(function(error, result)) {
        //do something then continue
    }
}

 //do this next whether condition is true or not

I assume that putting the code to come after in a function might be the way to go and call that function within the async call above or on an else call if condition is false - but is there an alternative way that doesn't require me breaking it up in functions?

Just an another way to do it, this is how I abstracted the pattern. There might be some libraries (promises?) that handle the same thing.

function conditional(condition, conditional_fun, callback) {
    if(condition)
        return conditional_fun(callback);
    return callback();
}

And then at the code you can write

conditional(something === undefined,
            function(callback) {
               fetch_that_something_async(function() {
                  callback();
               });
            },
            function() {

                       /// ... This is where your code would continue


             });

Just declare some other function to be run whenever you need it :

var otherFunc = function() {
   //do this next whether condition is true or not
}

if(condition) {
    someAsyncRequest(function(error, result)) {
        //do something then continue

        otherFunc();
    }
} else {
    otherFunc();
}