"Gwen:,
TWA did and does in fact track two numbers:
Lifetime Accumulated Miles (Including things like Hotels, Cars, Bonus Miles, etc.)
Lifetime TWA Flight Miles: Actual TWA flight miles only.
The never really used the first number for anything (unlike AA who uses it for their Lifetime Gold/Platinum levels). The second number they used to award their Lifetime Platinum status at 1MM actual fligth miles.
If you call them they can tell you...although they seem to take a few minutes on the phone to find it. You might have bettter luck using the TWA.com email system to get a direct response.