Discussion
COVID-19 has recently been responsible for a drastic surge in the cases
of CAM. We described the DNE findings of 102 patients in the target
group who underwent KOH mount irrespective of DNE findings. The observed
findings indicate the variable presentation of CAM. The aggressiveness
of CAM has changed, with normal nasal findings it has the potential to
invade orbit, sinuses, and brain. Imaging plays an important role in
making an early diagnosis. The reason attributed for this lack of
enhancement is the angioinvasive nature of fungal hyphae which
infiltrates the vessels supplying the mucosa5,6,7. In
our study, it was found that black turbinate sign was present in the
majority of the cases in MRI findings specific to sinonasal involvement
of disease. With these findings in the imaging, even a negative DNE
mandates a tissue diagnosis.
There is scarce literature among diagnostic utility of nasal endoscopy
in relation to common clinical, microbiological, and radiological
criteria in CAM.
Mohindra S et al8 reported in their study of 27
patients that the clinical suspicion, supplemented with radiological
investigations aid in making a correct diagnosis. In our study, we found
that even a negative endoscopy does not rule out the diagnosis of CAM.
We would like to propose that all target group patients should be
subjected to biopsy for KOH mount and imaging. Ferguson BJ et
al9 found that the aggressive evaluation of patients
with biopsy contributes to early detection of disease, which was in
coherence to our study. We found that in many patients the disease
pattern was sinus involvement before nasal involvement. Due to certain
limitations of DNE, it is not able to diagnose sinus involvement in
endoscopy, where imaging is paramount.
Gillespie MB et al10 showed the approach to diagnose
the disease at an earlier stage while it is confined to the nasal cavity
before the widespread extension to have a positive impact on survival.
Few authors have reported that turbinate sign is a radiological feature
in MRI which can aid in earlier detection of the
disease7. It is a moderately specific but significant
finding in rhino-orbito-cerebral mucormycosis. In our study, it was
found that a black turbinate sign in MRI is specific to sinonasal
involvement of disease. To summarize, in the setting of COVID-19, an
Otorhinolaryngologist must be vigilant at the imaging findings of CAM.
One should have a low threshold for biopsy and imaging even in cases
with normal endoscopy in target group patients to reduce false-negative
results