Brief description with key imaging findings allowing differential diagnosis of various forms of fungal sinusits. From Radiopaedia.org and Diagnostic Imaging: Head and Neck by H. Ric, Harnsberger.

1. Fungal sinusitis
Imaging findings
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2. forms
allergic (AFS)
chronic noninvasive (CNFS)
chronic invasive (CIFS)
acute invasive (AIFS)
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3. allergic fungal sinusitis
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4. chronic severe noninvasive form
immunocompetent, nondiabetic
atopic patient, asthma
long-standing symptoms of chronic RS
facial deformity, diplopia
serum eosinophilia, elevated IgE
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5. CT with soft tissue and bone window best
multiple sinuses, ethmoid > maxillary
hyperdense nonenhancing material
peripheral mucosa enhances
bone expansion +/- erosion
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6. DDX expansile sinonasal lesion
allergic fungal sinusitis
sinonasal poliposis
antrochonal polyp
mucocele
esthesioneuroblastoma
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7. Remember
symptomatic atopic patient
increased density in multiple sinuses with bone expansion
use soft tissue window to assess density of secretions
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8. chronic noninvasive fungal sinusitis
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9. also called mycetoma, fungus ball, aspergilloma
immunocompetent
non-atopic
minimally symptomatic
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10. 1 sinus, commonly maxillary
with high density mass with Ca++
which may be ovoid or conform to sinus shape
a/w chronic osteitis
fungus ball is hypo T1, hypo T2
coronal NECT best
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11. DDX
chronic rhinosinusitis
less likely to appear mass like
affects > 1 sinus
Ca++ more rare
allergic fungal sinusitis
atopy
high density material, low T1, T2
but with bone expansion
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12. chronic invasive fungal sinusitis
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13. the same as chronic noninvasive fungal sinusitis
high density material + chronic osteitis
+
invasiveness of fungal mass
extrasinus extension +/- bone erosion
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14. acute invasive fungal sinusitis
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15. acute onset in immunosuppressed patient
spread occurs via vascular invasion
can be fatal
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16. dense secretions
bone destruction
ill-defined spread to soft tissues
pterygopalatine fossa, masticator space, infratemporal fossa
orbit, intracranial fossa
! infiltration of fat planes can be present w/o bone erosion
via vascular channels
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17. CECT with soft tissue and bone window
soft tissue and muscles may enhance
MRI, T1+C FS if suspected orbital and intracranial complications
leptomeningitis, epidural abscess, subdural empyema, brain abscess
MRA, MRV
arterial pseudoaneuryrsm, thrombosis, dissection + brain ischemia
cavernous sinus thrombosis
! always look at cavernous sinus, cavernous ICA, and basilar artery
with sphenoid sinusitis
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18. DDX destructive sinonasal lesion with soft tissue involvement
acute invasive fungal sinusitis
acute rhinosinusitis
chronic invasive fungal sinusitis
granulomatosis with polyangiitis (Wegener’s)
sinonasal lymphoma
sinonasal carcinoma
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19. Questions to ask with fungal sinusitis
is the patient immunosuppressed?
is the patient atopic?
is the patient symptomatic?
one or more sinuses involved?
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20. Maria Cucos MD
allergic fungal sinusitis chronic noninvasive fungal sinusitis
atopy, asthma
chronic symptoms
multiple sinuses, ethmoidal +
hyperdense material
bone expansion +/- erosion
noninvasive
immunocompetent/mildly immunosuppressed
mildly symptomatic
one sinus, maxillary +
hyperdense material
osteosclerosis +/- volume reduction
noninvasive
chronic invasive fungal sinusitis acute invasive fungal sinusitis
diabetic patient
chronic symptoms
hyperdense material
osteosclerosis + bone erosions
extra-sinus invasion
immunosuppressed, diabetic
acute dramatic symptoms
hyperdense material less prominent
bone erosions, no osteosclerosis
extra-sinus invasion

21. Remember
context is important
consider AIFS in immunosupressed and diabetic patients
consider CNFS in immunocompetent patients or only
mildly immunosuppressed
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22. Remember
always look for signs of invasive disease
soft tissue infiltration/invasion
bone destruction
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23. Remember
consider AIFS in immunosuppressed patient
with maxillary disease + infiltrated periantral fat even if
no bone erosion is present
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