Two cases of nocardiosis diagnosed by fine-needle aspiration cytology: role of special stains.

Nocardiosis, a suppurative disease caused by aerobic actinomycetes, is a common opportunistic infection in immunocompromised patients. Unless, the infection is suspected, the diagnosis of Nocardia is tedious and difficult, as these are thin filamentous bacilli, which stain negatively on routine cytological stains. We present two such cases diagnosed on fine-needle aspiration cytology and discuss the importance of performing the modified Ziehl-Neelsen stain in such cases.