The Mirage of Cases
Suchita
The Mirage of Cases
Often in diagnostics, clinicians rely heavily on the patient’s medical history aided by the use of diagnostic tools to start a patient on any kind of relevant therapy. Diagnostics completely rely on the doctor’s ability to make sense out of a case and correlate the pathology behind it to link it with the treatment modalities available. However even doctors, despite being trained for years, are humans who can make errors in diagnostics.
Here is a simulated case which has been diagnosed with all the given facts to be a particular disease. But could it be something else?
Case:
A 24-year-old college student presents with intermittent fever for the 3 months accompanied by sweating at night and fatigue throughout the day. She says that she has lost about 8 kilograms and blames it on her lack of appetite in the hostel mess. She comes with complaints of a mild cough. A chest X- Ray taken showed a few ill-defined infiltrates.
The doctor’s interpretation:
Since tuberculosis has a high prevalence in India and the constitutional symptoms and radiological examination point towards the same, the provisional diagnosis made was pulmonary tuberculosis. The patient was started on an anti tubercular regime with the drugs isoniazid, rifampin, pyrizinamide and ethambutol.
So what went wrong after that?
After 2 months the patient returned to the Medicine OPD with complaints that the fever did not reduce and the weight loss continued despite improving her appetite and taking the medications. She came with new complaints of palpitations and cervical node enlargement. Her sputum was analysed and it repeatedly tested negative for the presence of acid-fast bacilli (Mycobacterium tuberculosis).
The deeper analysis:
The doctor on further evaluation noted generalised lymphadenopathy, splenomegaly and elevated lactate dehydrogenase levels. An excisional lymph node biopsy was performed which confirmed the presence of Reed-Sternberg cells. Immunohistochemistry indicated CD-15 and CD-30 positivity of the RS cells.
Final diagnosis:
Hodgkin’s Lymphoma
Why was it misdiagnosed?
Anchoring bias - the doctors relied too heavily on the first piece of information and took TB as the most likely cause
Availability bias - the easiest example that came to mind was tuberculosis compared to a rarer diagnosis like Hodgkin’s lymphoma
Premature closure - before fully obtaining the confirmation of the tissue pathological confirmation a diagnosis was made
Errors that could have been avoided:
Had the medical officer conducted a proper general examination, the enlargement of other lymph nodes could have been caught and the breath sounds could have been analysed for ruling out tuberculosis as the most likely diagnosis. Biopsies must be taken of suspicious lymph nodes as and when the patient presents and must not be left to just radiological examinations.