olfactory neuroblastoma

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ol·fac·to·ry neu·ro·blas·to·ma

a rare, often slowly growing malignant tumor of primitive nerve cells, usually arising in the olfactory area of the nasal cavity.


A rare malignant neuroectodermal tumour of the nasal cavity in the retrobulbar region, middle cranial fossa, near the cribriform plate. It is thought to arise from the olfactory membrane of the sinonasal tract.

Clinical findings
Bimodal age distribution, affecting those in the 2nd and 6th decades of life; presents as a unilateral nasal obstruction, epistaxis, anosmia and headache, accompanied by nonspecific symptoms similar to other intranasal lesions—i.e., congestion, rhinorrhoea.
Small round cell malignancies that occur in the sinonasal tract—e.g., sinonasal undifferentiated carcinoma, lymphoma, rhabdomyosarcoma and neuroendocrine carcinomas.

5-year survival 50–60%; late recurrence is common. Hyams’ grading system is used for grading; it incorporates architecture, rosette formation, mitoses, necrosis and pleomorphism, and correlates with survival.


pertaining to the sense of smell.

olfactory bulb
the bulblike extremity of the olfactory tract on the rostral surface of the frontal lobe of each cerebral hemisphere; it is lodged against the cribriform plate through which the olfactory nerves pass.
olfactory glands
in the mucosa of the nasal olfactory region; branched tubuloalveolar glands secreting serous fluid; cleanse the mucosal surface, dissolve odor-producing substances.
olfactory hair
modified cilia projecting from olfactory cells in the mucosa of the nasal olfactory area.
olfactory mucosa
specialized olfactory cells in a region of nasal mucosa covering ethmoturbinates, turbinates and nasal septum.
olfactory nerve
the first cranial nerve made up of about 20 bundles and concerned with the sense of smell. The cell bodies are situated in the olfactory mucous membrane of the nose. Nerve fibers lead upward through openings in the cribriform plate of the ethmoid bone and connect with the cells of the olfactory bulb. From there the fibers pass inward to the cerebrum. See also Table 14.
olfactory neuroblastoma
rare neoplasm, commonest in pups and kittens, characterized by local invasion of surrounding bone.
olfactory pit
primordia of the nasal cavities commencing as pits in the olfactory placodes of the embryo. The pits deepen and finally open into the oral cavity as the choanae; the external orifices become the nostrils. Called also nasal pit.
olfactory system
includes the olfactory part of the nasal mucosa, the olfactory nerves and the olfactory bulbs of the cerebrum.
olfactory tract
a band of white nerve fibers visible on the ventral surface of the brain running caudally from the olfactory bulbs.
olfactory tractotomy
surgical removal or transection of the olfactory tracts to produce an anosmia may be performed in cats as a means of controlling spraying and inappropriate urination.
References in periodicals archive ?
Olfactory neuroblastoma is not related to Ewing family of tumors: absence of EWS/FL1 gene fusion and MIC2 expression.
Hyams Histologic Grading System for Olfactory Neuroblastoma Microscopic Features Grade 1 Grade 2 Grade 3 Grade 4 Architecture Lobular Lobular With or With or without without lobular lobular Pleomorphism Absent to Present Prominent Marked Slight Neurofibrillary Prominent Present May be Absent matrix present Rosettes Present (a) Present (a) May be May be present (b) present (b) Mitoses Absent Present Prominent Marked Necrosis Absent Absent Present Prominent Glands May be May be May be May be present present present present Calcification Variable Variable Absent Absent (a) Homer-Wright rosettes (pseudorosettes).
Cytogenetic abnormalities (translocation) have been seen in association with olfactory neuroblastomas.
Radiologically, sinonasal NEC and sinonasal undifferentiated carcinoma are indistinguishable from olfactory neuroblastoma.
There is clinical relevance in distinguishing between sinonasal NEC and olfactory neuroblastoma because the latter is typically more aggressive and invasive.
The optimal management of olfactory neuroblastoma has been reported as a combination of surgical resection with adjuvant radiotherapy.
We know that olfactory neuroblastoma is chemosensitive and responsive to platinum-based agents, (16,17) but chemotherapy is currently reserved for unresectable or recurrent tumors and for metastases.
In conclusion, olfactory neuroblastoma requires aggressive surgical resection and radiation therapy.
Olfactory neuroblastomas (esthesioneuroblastomas) account for only 6% of these neoplasms.
Olfactory neuroblastomas arise from olfactory neuroepithelium, which extends from the roof of the nose to the area of the superior turbinates and a portion of the nasal septum.