Evaluation of Direct Examination, Culture, and Histopathology in the Diagnosis of Mucormycosis: Reiterating the Role of KOH Mount for Early Diagnosis

Cureus. 2021 Nov 10;13(11):e19455. doi: 10.7759/cureus.19455. eCollection 2021 Nov.

Abstract

Introduction Invasive fungal infections have always been a major cause of mortality and morbidity and are especially prevalent in the immunosuppressed groups of patients. Members of the Mucoracea family have an increasing incidence and prevalence. It has always been difficult to diagnose this condition due to various reasons. Materials and Methods This was an observational study carried out jointly by the Department of Microbiology and the Department of Pathology for a duration of one year. All patients who presented in various clinical departments with a high index of clinical suspicion for mucormycosis were included in this study. A total of 186 samples were received from suspected cases of mucormycosis and were all subjected to direct microscopy by potassium hydroxide (KOH), fungal culture, and histopathological examination. Results Mucormycosis was documented in 33 out of 186 cases on direct microscopy, whereas 21 were positive on fungal culture. Histopathological positivity was reduced with only 11 cases showing aseptate hyphae suggestive of mucormycosis. Conclusion As these organisms generally do not grow well on routine culture media and with the histopathological results also being not suggestive clearly of mucormycosis, direct microscopy thus becomes more important and essential in the rapid diagnosis of this deadly condition.

Keywords: fungal culture; histopathology examination; invasive fungal infection; koh preparation; “mucormycosis”.