Case of the Month: February 2023
Clinical history
A 40-year-old patient presented to the emergency room with a 12-hour history of chills, headache, and shortness of breath. The patient was previously seen for an opioid overdose.
Physical examination revealed vitals as follows:
- T 39.2°C
- BP 106/72
- HR 108
- RR 20
- O2 sat 94% on RA.
The patient appears anxious and unwell. Cardiac exam showed a systolic murmur, loudest at the right 2nd intercostal space. Eye exam showed conjunctival petechiae. Examination of the extremities revealed track marks in the antecubital fossa and erythematous macules on the palms.
A CT scan was ordered; however, the patient collapsed. Resuscitation efforts were unsuccessful and the patient died.
Take a look at these images from an H&E section of the patient’s mitral valve. Then visit the case of the month post on our Instagram page and comment your diagnosis to participate.
Discover the answer to February's case of the month!
The answer to the February Case of the Month is ‘infective endocarditis’. The key histological features in acute cases are valve tissue with thrombus containing neutrophilic inflammation and fibrinoid necrosis. Micro-organisms may be seen in some cases.
Infective endocarditis is primarily a clinical and microbiological diagnosis. Major criteria include strong microbiological evidence such as 2 blood cultures growing typical organisms (S. aureus, viridans group strep, enterococcus, HACEK group) and evidence of endocardial involvement by echocardiogram. Minor criteria include predisposition (e.g. prosthetic valve, intravenous drug use), fever >38C, vascular phenomena, immunological phenomena, and weak microbiological evidence. Definitive infective endocarditis = 2 major criteria or 1 major + 5 minor criteria. Possible infective endocarditis = 1 major + 1 minor criteria or 3 minor criteria.
Next time you encounter a patient and suspect infective endocarditis, at least two sets of blood cultures and an echocardiogram are very helpful in establishing the diagnosis.
Stay tuned for the March Case of the Month, which will be posted mid-March!
If you are a current medical student at U of T, you can register to join the March case of the month lecture online or in person.
If you’re a medical student at the University of Toronto interested in Laboratory Medicine join the Special Interest Group in Laboratory Medicine to be invited to a case of the month lecture (catered).
