PERIPHERALIA

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In the last column we featured a professor of surgery, a 
Franciscan monk, a Nigerian author and a professor of 
medicine. In this following column we have a bank robber, 
another professor of medicine, a pathologist and a surgeon.

On this same subject of clinical reasoning, I would like to 
believe that we follow sequences and strive to be logical in 
our investigations, bloods tests and imaging. Appropriate 
tests are ordered to confirm or refute the hypotheses that 
we have formed from the patient’s history and examination. 
Nevertheless, if we let the patient out of our hands into the 
medical market place, they may receive a whole battery of 
tests and scans in the close-your-eyes-and-tick-all-the-boxes 
system. This umbrella or shotgun approach is often done 
because of fear of litigation and also to protect the doctor’s 
reputation in case a diagnosis is missed.

The temptation to over investigate arises when most of the 
symptoms fit into one diagnosis but one symptom or sign 
does not fit the primary hypothesis. One can then spend a 
considerable amount of time and money searching for the 
cause of the outlier. It may, on the one hand, be the key to a 
secondary diagnosis or, on the other hand, a red herring and 
one ends up looking at night in a coal cellar for a black cat 
that is not there.

In act two of this production, the bank robber Willie Sutton 
takes the stage. He reputedly replied to a reporter’s enquiry 
as to why he robbed banks by saying “because that is where 
the money is”. In medicine, if we follow Sutton’s thought 
process then we should only be using those tests that, from 
our primary hypotheses, are relevant to the case in question.

Instead of Sutton’s system of concentrating on the likely 
diagnosis, we now tend to scan the patient “to be on the safe 
side”.  This leads to a great many normal results. For instance 
the percentage of CT brain scans done for headaches that 
turn out to be positive (that is showing something wrong 
with the brain) is between 6 and 13 percent. So William 
Sutton would be wise to rob the banks that contained the 
doctors’ bank accounts and not the patients’ accounts.

The scene now shifts to 1991 when a pathologist called 
Horton A Johnson from Columbia University in New York 
enters the arena. He wrote a landmark paper in the Journal of 
the American Medical Association called Diminishing Returns 
on the Road to Diagnostic Certainty. As one approaches 

diagnostic certainty, he says, the useful information 
returned by diagnostic tests approaches zero. After our 
first line of investigations there is not much information 
gained by carrying on to a second or third session of blood 
tests or imaging. One then goes into “diagnostic overkill” 
and the expenses increase. This is not without its own 
problems because of “incidentalomas” that send one off on 
another goose chase of investigations. These investigations 
in themselves may then lead to further side effects or 
complications, which has been called the Ulysses Syndrome. 
This was first described in the Canadian Medical Journal in 
1972 by Dr Mercer Rang, a surgeon from Toronto. Ulysses 
fought in the Trojan war and afterwards it took him ten 
years to get home (which is even longer to get home than in 
Johannesburg). On his journey home he had many dangerous 
adventures and patients with Ulysses syndrome may have 
similar journeys through the technology of modern hospitals 
with inappropriate or unnecessary investigations. 

Papers from 1972 and 1991 are not exactly hot off the press 
but they have stood the test of time. One of the great tests 
that we were allowed in the past was “the test of time”. Many 
symptoms and conditions cure themselves or fade away 
over time but the art of waiting has almost disappeared. The 
clients want to know the final solution now. Nature and the 
natural course of illness must wait for another day.

Now entering the fray for the final act is Theodore 
Woodward, a professor of medicine at the University of 
Maryland. He comes in on the side of Willie Sutton and 
while teaching his students on the skills of diagnosis says 
“when you hear hoof beats, think horses not zebras”. This 
does not necessarily apply if you practise medicine in the 
Kruger National Park or Umfolozi Game Reserve. As students 
we often become imprinted with those really fascinating 
explanations of rare illnesses such as Addison’s disease and 
phaeochromocytomas. They explain the physiology and 
causation of illness in an eloquent and understandable way 
and are called fascinomas.

All my practice life I have been waiting for a patient with 
hypertension, caused by phaeochromocytoma, to enter my 
consulting room. To me it has now become a mythoma.

Chris Ellis is a family physician in Pietermaritzburg, 
KwaZulu-Natal

E mail: cristobalellis@gmail.com

Sutton’s law, Phaeochromocytomas  
and Zebras