Phaeohyphomycosis: Cytomorphologic Evaluation in Eleven Cases

Abstract

Objective: Phaeohyphomycosis caused by phaeoid fungi is a type of mycosis emerging worldwide which causes a wide variety of clinical manifestations.

Study design: A retrospective analysis of 11 cases diagnosed with fungal inflammation on cytology over a period of 6 years (2013-2018) was done along with culture/histopathologic confirmation.

Results: Of the total of 11 cases, 9 cases presented with subcutaneous swellings and 1 case each with brain and lung lesions. The age range was 30-83 years (mean: 53.6); 8 patients were male and 3 were female. Cytologic smears showed fungal profiles with septate tortuous hyphae, as well as swollen and narrow, yeast-like swellings with an irregular breadth of the hyphae in all cases. The fungal profiles were visualized on a Masson-Fontana stain. The background showed inflammatory cells, giant cells, and necrosis in variable proportions. Five cases were diagnosed as phaeohyphomycosis on cytology, whereas 3 cases were misdiagnosed as aspergillus and 2 as candida. In 1 case, typing of the fungus was not done. Histopathology was available in 5 cases, and in all these a diagnosis of phaeohyphomycosis was reached. Ten of the 11 cases had confirmation on fungal culture.

Conclusions: Phaeoid fungi are rarely seen in routine cytologic practice. Careful evaluation of cytologic smears and an awareness of the characteristic morphologic features of phaeohyphomycosis are helpful in arriving at a correct diagnosis. Fine needle aspiration cytology provides a rapid diagnosis, enabling prompt therapy.

Keywords: Cytomorphology; Fine needle aspiration cytology; Phaeohyphomycosis; Subcutaneous swelling.