Introduction
The sinus fungal ball is defined as an agglomeration of debris and
hyphae within the paranasal sinus, commonly affecting a single
sinus1. It most often affects the maxillary sinus,
followed by the sphenoid and ethmoid sinus, and frontal sinus affection
is extremely rare implicated in only about 2% of all involved
sinus2, 3, 4. There is a slight female
predominance5 and, in most cases, it manifests itself
during the fourth and fifth decade of life, as a result of respiratory
infection by Aspergillus sp 6.
Aspergillus fumigatus and Aspergillus
flavus 6 are the main species involved in fungal
rhinosinusitis. Aspergillus is a genus of anamorphic fungi, which
is characterized by having filamentous fungi with hyaline hyphae,
septate and branched at an acute angle7. They dominate
warmer areas, being more common in tropical countries. Several species
of Aspergillus have importance for humans due the ability to
produce toxic metabolites, mainly A. fumigatus , which has a
fast-growing, bluish-green, and powdery colony. A. flavus , on the
other hand, is a filamentous fungus that can produce aflatoxins and
cyclopiazonic acid that results in atoxic effect on the
hosts8,9.
Fungal rhinosinusitis comprises between 4% and 10% of surgical
interventions in the paranasal sinuses region and can be subdivided into
invasive and non-invasive10, 11. Non-invasive fungal
rhinosinusitis is typical of immunocompetent
patients12, classified as a fungal ball or allergic
fungal rhinosinusitis13.
The slow and oligosymptomatic development of fungal ball in the frontal
sinus often leads to late diagnosis, with orbital or intracranial
complications as the first clinical signs14. The
diagnosis of fungal ball is difficult, occasionally identified by
Computed Tomography (CT) or Magnetic Resonance Imaging
(MRI)5, 15 and surgery with an endonasal endoscopic
approach is the treatment of choice2, 16.