Microsoft unit testing. Is it possible to skip test from test method body?

You should not skip test this way. Better do one of following things:

• mark test as ignored via [Ignore] attribute
• throw NotImplementedException from your test
• write Assert.Fail() (otherwise you can forget to complete this test)
• remove this test

Also keep in mind, that your tests should not contain conditional logic. Instead you should create two tests - separate test for each code path (with name, which describes what conditions you are testing). So, instead of writing:

[TestMethod]
public void TestFooBar()
{
   // Assert foo
   if (!bar)
      return;
   // Assert bar
}

Write two tests:

[TestMethod]
public void TestFoo()
{
   // set bar == false
   // Assert foo
}

[Ignore] // you can ignore this test
[TestMethod]
public void TestBar()
{
   // set bar == true
   // Assert bar
}

You can ignore a test and leave it completely untouched in the code.

[TestMethod()]
[Ignore()]    //ignores the test below
public void SomeTestCodeTest()
{
   //test code here

}

Further to other answers (and as suggested): I'd suggest using Assert.Inconclusive over Assert.Fail, since the original poster's situation is not an explicit failure case.

Using Inconclusive as a result makes it clear that you don't know whether the test succeeded or failed - which is an important distinction. Not proving success doesn't always constitute failure!