Esthesioneuroblastoma (ENB)
Esthesioneuroblastoma (ENB), originally described in 1924, AKA olfactory neuroblastoma, AKA olfactory esthesioneuroblastoma, AKA esthesioneurocytoma, AKA olfactory placode tumor 1).
Malignant tumor of sinonasal origin.
Epidemiology
A rare nasal neoplasm with an incidence of 0.4 per 1,000,000 people. 2).
Believed to arise from the olfactory neural crest cells in the upper nares, it is considered to be malignant. These tumors occur over a wide age range (3 to 90 years), with a bimodal peak between the second and third decade and a second peak in the sixth and seventh decades.
Classification
Esthesioneuroblastoma classification.
Clinical features
These tumors typically present with unilateral nasal obstruction and epistaxis.
Diagnosis
Diagnosis is confirmed on biopsy.
MRI: isointense with the brain on T1-weighted imaging and intermediate to high signal intensity on T2- weighted imaging and enhance heterogeneously with gadolinium. Signal characteristics may mimic meningioma. For higher stage lesions, the cribriform plate may be eroded; better seen on thin-cut CT. The most important factor determining resectability is an intracranial extension. Magnetic resonance aids in the distinction between extradural tumors, dural invasion, or parenchymal brain invasion. None of these are specific to this tumor.
Endoscopic biopsy is typically performed in the otolaryngology office prior to surgery. A clinical oncology exam should be performed, and if there is suspicion for metastatic disease a PET scan, which is sensitive for metastatic disease, should be ordered.
Differential diagnosis
Includes SNUC, nasal melanoma, nasal squamous cell carcinoma, and meningioma.
Treatment
see Esthesioneuroblastoma treatment.
Outcome
Esthesioneuroblastoma outcome.
Case series
Esthesioneuroblastoma case series.
Case reports
Esthesioneuroblastoma case reports.