An unusual case of Munchausen syndrome by proxy. 
An 11-year-old boy was presented by his father with a long and plausible history of cystic fibrosis.  The diagnostic test for cystic fibrosis, the sweat test, was normal and excluded the diagnosis.  The medical history was later found to be false, and the child to be well.  By definition, the case met the criteria for Munchausen Syndrome by Proxy with fabrication of symptoms on behalf of another in order to deceive medical personnel.  Unusual features included the illness chosen, the father as the parent falsifying illness, his failure to pursue unnecessary investigations and treatment, and the ease with which he relinquished the diagnosis of cystic fibrosis.