A Good Diagnosis: Reasoning and System interacting

A 70-years old man went to the Emergency Department (ED) with high fever (38º C). He had a previous diagnosis of superficial bladder carcinoma six months before treated with transuretral resection and intravesical BCG instillation. He had urinary emergency but negative urinary cultures. A diagnosis of urinary infection was established at the ED.

CLINICAL EVOLUTION: Fever started two weeks ago after the first intravesical instillation.Mild cough was also present. Blood test and physical examination were normal. An internist was called to evaluate the patient. He was not satisfied with the explanation of urinary infection. The X-Ray showed interstitial lines and a micronodular bilateral infiltrate not easy to detect. The doctor, using an amplifier for the X-ray, evidenced a bilateral micronodular infiltrate compatible with miliary tuberculosis.

FINAL DIAGNOSIS: Pulmonary miliary tuberculosis after intravesical BCG instillation (M.bovis).
ANALYSIS and COMMENT:
Cognitive aspect: the clinical reasoning of the internist physician was not satisfied with the first diagnosis of urinary infection, because this is less common in a man, and urinary cultures were negative (not premature closure).
System aspects: Electronic medical records and digital radiology have several utilities that can be very useful to search for more details, as we saw here with the use of a magnifier.

Disseminated Mycobacterium bovis after intravesicular bacillus calmette-Guerin treatments for bladder cancer. Elkabani M, Greene JN, Vincent AL, VanHook S, Sandin RL. Cancer Control. 2000 Sep-Oct;7(5):476-81.