This was a case shared by a co-resident a few days back after receiving a referral for examining a cerebrospinal fluid. The patient was suspected to have meningitis but the physician wanted to rule it out and if it's ruled in, what was the possible cause?
This looks like you typical Cryptococcus neoformans based from the typical pictures you see on textbooks. Now it would have been a simple case until I brought up the question of whether the lab changed its batch of India Ink? I had a false positive case where the same fungi was a contaminant.
Confirmation bias is a natural tendency for people to find ways to confirm they are right rather than figure out where their assumptions might have been wrong. Now rookie me would have just signed out the case as Cryptococcal infection but now I always compare the stains with patient samples vs normal saline.
Cases like these required one to view the stain with the patient's sample vs stain with normal saline. If the fungi is still present on plain normal saline, it's like the stain was contaminated.
It would have been disastrous if the patient was treated for meningitis caused by fungal infection. Antifungals are expensive here.
If you made it this far reading, thank you for your time.
