Esthesioneuroblastoma is a tumor arising from the basal layer of the olfactory epithelium in the superior recess of the nasal cavity.

Usually, this tumor begins as a mass in the superior olfactory recess and initially involves the anterior and middle ethmoid air-cells on one side. As it grows, it tends to destroy surrounding bone, and can extend in any direction. 

Some relevant aspects of this tumor:

• peaks in young adult patients (~2^nd decade) and another peak in the 5^th to 6^th decades
• nasal stuffiness and rhinorrhea or epistaxis are also referred as primary symptoms 
• arises from the basal layer of the olfactory epithelium in the superior recess of the nasal cavity
• slow growing tumor 
• tends to destroy surrounding bone, and can extend in any direction
• on imaging they usually present as a soft tissue mass in the superior olfactory recess involving the anterior and middle ethmoid air cells on one side and extending through the cribriform plate into the anterior cranial fossa. 
• contrast enhancement is often marked in both CT and MRI studies. 
• treatment usually involves combined chemotherapy and/or radiotherapy with surgical excision.
• prognosis is significantly affected by presence of distant metastases