Fungal Rhinosinusitis: Microbiological and Histopathological Perspective

On the basis of histopathology Fungal Rhinosinusitis (FRS) is categorized into non-invasive (allergic fungal rhinosinusitis, fungal ball) and invasive (acute invasive, chronic invasive and granulomatous invasive fungal sinusitis). This differentiation helps to decide the treatment. Role of latest molecular methods such as PCR and conventional methods such as KOH microscopy and culture also needs to be evaluated. Therefore, in this study we planned to categorise fungal rhinosinusitis on the basis of histopathology and compare it with other methods such as PCR, culture and KOH microscopy.

To analyse fungal rhinosinusitis cases by both histopathologically and microbiologically.

A total of 76 clinically suspected fungal rhinosinusitis cases were included in the study. The tissue of suspected cases were processed and examined by KOH microscopy, histopathologically, culture and PCR. Histopathological examination was done by PAS, GMS and H&E stain.

FRS was diagnosed in 37 (48.68%) cases out of 76 clinically suspected cases of FRS. In which 17 (22.3%) cases were positive by direct microscopy, 21 (27.6%) by culture, 27 (35.5%) by PCR and 14 (18.42%) by histopathology. Approximately 14 cases of FRS were classified according to histopathology; 10 (71.3%) as non-invasive FRS. Out of these 10, 9 (64.2%) were classified as AFRS and 1 (7.14%) as fungal ball. Only 4 cases (28.5%) were diagnosed with invasive FRS. Out of these 4 cases, 2 (14.2%) were of chronic invasive fungal rhinosinusitis, 1 (7.14%) was of granulomatous invasive fungal rhinosinusitis and 1 (7.14%) was of acute fulminant invasive fungal rhinosinusitis. Allergic Fungal Rhinosinusitis (AFRS) is the most common type of FRS. Aspergillus flavus was found to be the most common fungi causing FRS.

Diagnosis should not be based on the single method. It should be done by both histopathological and microbiological methods, especially for those cases which are difficult to diagnose.