OLFACTORY NEUROBLASTOMA

Dr.K.Anandhakumar

Post Graduate DLO

OLFACTORY NEUROBLASTOMA

46Y/F referred to our institution as neuro

endocrine tumor left nasal cavity

c/o bleeding through left nasal cavity one month

ago lasted for 2 days

Under gone excision biopsy 2 month ago in

private hospital for left nasal cavity mass as

sino nasal malignancy and biopsy showed as

neuro endocrine tumor

MENSTRUAL H/O

Irregular menstrual cycle

h/o PS done 16 years back

TRANS NASAL ENDOSCOPIC EXCISION OF LEFT

NASAL CAVITY MASS

BIOPSY REPORT

Malignant round cell neoplasm – features

suggestive of olfactory neuroblastoma

IHC

SYNAPTOPHYSIN – focal positive in tumor

cells

CYTO KERATIN _ negative

CHROMOGRANIN _ Negative

POST OPERATIVE CT

POST OP DNE

DISCUSSION

Olfactory neuroblastoma first described by

BERGER & LUC in 1924.

Probable origin :

sphenopalatine ganglion ,

vomero nasal organ of Jacobson,

neuroepithelial cells of the olfactory membrane,

ectopic olfactory epithelium in nasal mucosa &

APUD cells

DISCUSSION

Olfactory neuroblastoma –arises from basal

cells within the olfactory neuro epithlium.

Represents < 5% of all sinonasal

malignancies

Incidence : Bimodal distribution , peak at 20

& 50 years of age

Common in females

PATHOPHYSIOLOGY

Undifferentiated tumour of neuroectodermal

origin derived from olfactory neuroepithelium

Tumour cells are mitotically active that

develop into sustentacular & neuronal cells

It contains variable arrangement of small

cells

There exist variable presence of true

rossettes & neurofibrillary material

Neuro endocrine tumor capable of causing

paraneoplastic syndromes by secreting

peptides

Can cause Cushing’s syndrome ,

inappropriate anti diuretic hormone secretion

or hypertension produced by vasoactive

peptides

CLINICAL FEATURES

COMMON :

nasal obstruction ,

epistaxis ,

persistant nasal

discharge

LESS COMMON:

sinus pain ,

visual changes ,

head ache,

proptosis ,

Diplopia,

Hyposmia,

Anosmia,

facial pain,

facial swelling & syncope

INVESTIGATIONS

CT : homogenous soft tissue mass in the nasal cavity producing

some erosion of lamina papyracea ,

cribriform plate & fovea ethmoidalis

MRI : T1 weighted image : hypo intense to gray matter

T2 weighted image : iso / hyper intense

IMMUNO HISTO CHEMISTRY

Synaptophysin

Neuro filament protein

S100

Chromogranin

Neuron specific enolase

DIFFERENTIAL DIAGNOSIS

Ewings sarcoma

Lymphoma

Poorly differentiated sarcoma & carcinoma

HYAM’S HISTOLOGICAL GRADING

Based on

degree of differentiation ,

tumor architecture ,

mitotic index ,

nuclear polymorphism ,

fibrillary nature of matrix & tumour necrosis

KADISH CLINICAL STAGING SYSTEM

WITH MORITA’S MODIFICATION

A – limited to nasal cavity

B – involving nasal cavity & sinuses

C – extension beyond nasal & paranasal

sinuses cavities

D – tumour with metastasis to cervical nodes

or distant sites

TREATMENT

Surgery followed by adjuvant radiotherapy

Surgery

CRANIOFACIAL approach involving ENT , Head &

Neck and neurosurgical treatment

Radiotherapy

For stage A & B 4500 – 5500 rads for 5 weeks

For stage C 6000 – 6500 rads for 7 weeks

Recurrent metastatic disease –

Chemotherapy

Cisplatinum – 60 mg/ sq. m on day 1

Etoposide – 120 mg / sq. m on day 1,2,3

Cyclophospamide ,thio – TEPA ,high dose

CAV with stem cell support also used

PROGNOSIS

5 & 10 Year survival rate – 80 % & 50 % with

radical surgical procedure followed by RT

POOR PROGNOSTIC FACTORS:

Age > 50 at presentation

female gender

Tumour recurrence

metastasis