 Introduction/Background According to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS), the term rhinosinusitis refers to symptomatic inflammation of the nasal cavity and paranasal sinuses and is preferred over the term sinusitis, because inflammation of the nasal cavity nearly always accompanies inflammation of the contiguous paranasal sinuses. Rhinosinusitis may be classified as acute rhinosinusitis (ARS) if symptoms last <4 weeks or as chronic rhinosinusitis (CRS) if symptoms last >12 weeks [1]. Patients with acute bacterial rhinosinusitis (ABRS) may develop orbital, intracranial, and vascular complications, including orbital cellulitis, subperiosteal abscess, intracranial abscess, cerebritis, cavernous sinus thrombosis, and aneurysm. Acute recurrent rhinosinusitis refers to when patients have 4 or more episodes of rhinosinusitis per year without persistent symptoms between episodes. CRS is one of the most common chronic illnesses in the United States, affecting approximately 12% to 16% of the population [2], with an overall annual economic burden estimated at $22 billion [3]. Acute invasive fungal sinusitis is a fungal infection of the paranasal sinuses with a rapid time course of <4 weeks [4] and a high mortality rate of 50% to 80% [5,6]. Affected patients are typically immunocompromised and include patients with neutropenia, hematologic malignancies, poorly controlled diabetes, acquired immunodeficiency syndrome, organ transplantation, and patients on immunosuppressive therapy including systemic steroids and chemotherapy [4]. Presenting symptoms are nonspecific and include fever, rhinorrhea, and diplopia, similar to those seen with ABRS. Clinicians should maintain a high index of suspicion for this diagnosis in immunocompromised patients with symptoms of ARS, orbital symptoms, and/or headache. [4]. Sinonasal neoplasms account for 3% of head and neck neoplasms [7].
Sinonasal Disease.  Introduction/Background According to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS), the term rhinosinusitis refers to symptomatic inflammation of the nasal cavity and paranasal sinuses and is preferred over the term sinusitis, because inflammation of the nasal cavity nearly always accompanies inflammation of the contiguous paranasal sinuses. Rhinosinusitis may be classified as acute rhinosinusitis (ARS) if symptoms last <4 weeks or as chronic rhinosinusitis (CRS) if symptoms last >12 weeks [1]. Patients with acute bacterial rhinosinusitis (ABRS) may develop orbital, intracranial, and vascular complications, including orbital cellulitis, subperiosteal abscess, intracranial abscess, cerebritis, cavernous sinus thrombosis, and aneurysm. Acute recurrent rhinosinusitis refers to when patients have 4 or more episodes of rhinosinusitis per year without persistent symptoms between episodes. CRS is one of the most common chronic illnesses in the United States, affecting approximately 12% to 16% of the population [2], with an overall annual economic burden estimated at $22 billion [3]. Acute invasive fungal sinusitis is a fungal infection of the paranasal sinuses with a rapid time course of <4 weeks [4] and a high mortality rate of 50% to 80% [5,6]. Affected patients are typically immunocompromised and include patients with neutropenia, hematologic malignancies, poorly controlled diabetes, acquired immunodeficiency syndrome, organ transplantation, and patients on immunosuppressive therapy including systemic steroids and chemotherapy [4]. Presenting symptoms are nonspecific and include fever, rhinorrhea, and diplopia, similar to those seen with ABRS. Clinicians should maintain a high index of suspicion for this diagnosis in immunocompromised patients with symptoms of ARS, orbital symptoms, and/or headache. [4]. Sinonasal neoplasms account for 3% of head and neck neoplasms [7].