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Differentiation of histoplasma and cryptococcus in cytology smears: a diagnostic dilemma in severely necrotic cases
Author(s) -
Ranjan R.,
Jain D.,
Singh L.,
Iyer V. K.,
Sharma M. C.,
Mathur S. R.
Publication year - 2015
Publication title -
cytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 48
eISSN - 1365-2303
pISSN - 0956-5507
DOI - 10.1111/cyt.12180
Subject(s) - histoplasmosis , pathology , histoplasma , cytology , cryptococcus , blastomyces , serology , staining , papanicolaou stain , histoplasma capsulatum , cytopathology , biology , medicine , blastomyces dermatitidis , blastomycosis , microbiology and biotechnology , immunology , antibody , cancer , genetics , cervical cancer
Objective The correct identification of fungal organisms is important for the appropriate clinical management of patients. It becomes difficult in necrotic smears when the tissue response is not clearly discernible. It is difficult to distinguish between histoplasma and cryptococcus in severely necrotic cases, where both appear as variably sized clear refractile haloes. Methods Four cases of adrenal necrotic histoplasma infection were studied and the morphology was compared with that of non‐necrotic histoplasmosis and cases of cryptococcal infection. Eleven cases were analysed in fine needle aspiration cytology ( FNAC ) smears. Ziehl–Neelsen ( ZN ) stain was performed to exclude tuberculosis in necrotic smears. A clinical and serology correlation was performed where available. Results Necrotic cases of histoplasma infection revealed negative refractile clear haloes similar to those of cryptococcus . Histoplasma showed methylene blue‐stained organisms in ZN stains, whereas the cryptococcus cases were negative. Similar methylene blue‐stained organisms were seen in non‐necrotic histoplasma infection. Conclusion As a result of morphological overlap between cryptococcus and histoplasma , the distinction between the two fungi can be difficult in many cases. ZN staining appears to have a role in the differentiation of these fungi in severely necrotic cases. This observation needs to be validated on a larger number of cases with complete correlation with clinical, serology and treatment records.