Olfactory neuroblastoma

MR IMAGING IN OLFACTORY NEUROBLATOMA

1. OLFACTORY NEUROBLASTOMA ESTHESIONEUROBLASTOMA MERCURY IMAGING INSTITUTE SCO 172-173 SEC 9C CHANDIGARH MERCURY IMAGING CENTRE SCO 16-17 SEC 20D CHANDIGARH 16 yr old male with recurrent nasal bleeding. Plain MR study of the brain / nasal region reveals ....................... Large mass along the left side nasal fossa with lobulated contour and multicompartment extension. Macrocyst along the periphery of the intracranial component of the lesion. Interspread haemorrhage , microcysts in the core of the lesion. Epicentre along the left nasal fossa with more of the longitudinal than horizontal extension.

2. Esthesioblastoma a brief.............. Esthesioneuroblastomas are histologically similar to adrenal or sympathetic ganglionic neuroblastomas and retinoblastomas . Or iginally descried by Bergen et al. in 1924 as esthesioneuroepithelioma olfactif . Incidence peaks once in 11-20 years of age group and again in 50-60 years age group :However , age of these patients ranges from 3-88 years. It occurs equally in men and women. Synonyms include olfactory esthesioneuroma , neuroesthesioma and olfactory neurocystoma .

3. EPICENTRE OF THE LESION IS MORE ANTERIORLY LOCATED AND HELPS TO DISTINGUISH OLFACTORY NEUROBLATOMA FROM OTHER PATHOLOGIES LIKE Chordoma Nasopharyngeal carcinoma. Pitutary macroadenoma Juvenile angiofibroma EXTENSION OF THE LESION IS CRANIAL AND HELPS TO DISTINGUISH OLFACTORY NEUROBLASTOMA FROM Meningioma / Pericytoma usually grow inferiorly PERITUMORAL CYSTS ARE APRPECIATED ALONG THE PERIPHERAL PART OF THE INTRACRANIAL EXTENT OF THE OLFACTORY NEURO BLASTOMA : Not appreciated in rest of the lesions Like : Rabdomyosarcoma . An olfactory neuroblastoma (also known as an  esthesioneuroblastoma ) is a tumour arising from the basal layer of the olfactory epithelium in the superior recess of the nasal cavity.

4. T2w SEQUENCE – large macrocyst with intermediate signal core contents in the intracranial part of the Mass . Multicompartment involvement extending from the nasal cavity to sinuses to intracranial compartment. ESTHESIONEUROBLASTOMA IS ALMOST ALWAYS UNILATERAL . ONLY NEGLECTED CASES MAY PRESENT AS BILATERAL NASAL FOSSA MASSES.

5. T2w sequence – Macrocyst with variegated intermediate signal core contents . Appreciate the buckling of the adjacent brain parenchyma

6. No inversion of the cystic component of the mass lesion on FLAIR sequence.

7. SAGITTAL PLANE

8. INTERMEDIATE TO HYPERINTENSE SIGNAL ON t1w SEQUENCE No inversion of the core contents on the fat sat sequence.

9. No pathological restriction of diffusion . Interspread bloom on GRE sequence suggestive of haemorrhage / calcification

10. Points of interest.................. Multicompartment involvement. Usually unilateral lesion. Longitudinal pattern of extension. Macro/ microcysts along the periphery of the intracranial part of the lesion.