Final answer:
An India ink stain showing cysts is commonly associated with a cryptococcal infection, especially cryptococcal meningitis, which can be diagnosed by the characteristic encapsulated yeast cells visible under a microscope.
Step-by-step explanation:
An India ink stain showing cysts should make one think of the diagnosis of cryptococcal infection. Cryptococcus neoformans, a fungal pathogen, is known to produce these cyst-like structures surrounded by thick capsules, which are readily visible with India ink staining, a negative staining technique used in microbiology.
When viewed under a microscope, the India ink absorbs the surrounding light, making the capsules stand out as halo-like structures around the yeast cells. The detection of these encapsulated yeast cells is significant for diagnosis, particularly in cases of cryptococcal meningitis, which is a serious infection of the central nervous system.