The Molecular Genetics of Inflammatory, Autoimmune, and Infectious Diseases of the Sinonasal Tract: A Review

Abstract

The sinonasal tract is frequently affected by inflammatory lesions that arise through complex interactions of environmental, infectious, and genetic factors. Because these lesions are all inflammatory in nature, the molecular pathology surrounding them is most commonly due to upregulation and down-regulation of genes that affect inflammatory responses and immune regulation.

Pathology of Fungal Rhinosinusitis: A Review

“…Allergic FRS is not considered to represent a true fungal infection but is rather a result of an inflammatory reaction toward fungi in the sinonasal tract [13][14][15][16][17][18]. Interestingly, fungi begin to inhabit the sinonasal tract during the first few months of life [19]; however only a fraction of individuals develop allergic FRS.…”

“…2, 3). Eosinophilic mucin is now the preferred term instead of allergic mucin since there is debate regarding whether the etiology of this mucinous material, as well as allergic FRS, is allergic at all [1,2,17,18,[20][21][22][23][24][25][26][27][28][29]. Fungal hyphae are occasionally seen on H and E stain but are best highlighted by histochemical stains such as silver or periodic acid Schiff (PAS) (Fig.…”

“…However, not all patients with the pathologic diagnosis of allergic FRS have systemic (or even local) hypersensitivity to fungi. More recent studies indicate that fungi induce production of eosinophil attracting T h 2 cytokines and the subsequent inflammatory reaction produced results in the formation of allergic mucin [7,17,18,20,29]. Fungal proteases can induce the production of cytokines attract an influx of inflammatory cells including eosinophils which migrate through the barrier epithelial cells in response to fungi present.…”

Differential Diagnosis of Necrotizing Sinonasal Lesions

“…2,3 These infections can result in tissue necrosis and, chronically, can lead to midline destruction and deformity, similarly to many other necrotizing inflammatory processes of the sinonasal tract. A complete detailed presentation of sinonasal infections is beyond the scope of this review.…”

“…2,3,14 There is higher prevalence in patients from those countries and they may be considered for this etiology/differential diagnosis. Grossly, the lesions present as a soft, friable hemorrhagic polyp.…”