Check out this Lisa Sanders/NY Times article if you think that a trail of specialists is the surest way to figure out a knotty medical problem:

How come not one of the dozens of doctors ó including an endocrinologist ó that he saw over the nearly 15 years of interrupted sleep and other symptoms figured out that he had acromegaly? Perhaps because the various symptoms of his tumor were, for the most part, common problems: insomnia, high blood pressure, allergies and acne. They developed separately, years apart, and each was addressed by a specialist. It would take an act of imagination to link these symptoms. The patient never made that leap, and neither did any of his doctors. [.  .   .]

Not long after meeting [the doctor who finally made the correct diagnosis], the patient visited his primary-care doctor ó the doctor who had known him for years ó and told her that acromegaly was being considered. No way, she first told him. But sitting there, looking at his face and thinking about the changes caused by this disease, she began to reconsider. He did have the characteristically broad chin and nose. He was wearing braces because of changes in his jaw and teeth. His hands were huge. Suddenly, she could see the possibilities. Maybe he did have acromegaly.

The diagnosis was staring her in the face for years, but she did not see it. Psychologists call this inattention blindness ó instances when we donít see something because itís not what we are expecting to see; itís not what we are looking for. Sherlock Holmes had a somewhat different description. ìI have trained myself to notice what I see,î Holmes says.Arthur Conan Doyle, himself a physician, imbued his character with the kind of keen observational skills so essential to a good physician. This ability consists of casting a wide net to see the whole picture ó even when the complaint that brings the patient to medical attention is commonplace, like insomnia.