Nasal polyps are non neoplastic masses of nasal or sinus mucosa. The differential diagnosis for nasal polyp are:

Hypertrophic turbinates – (see how How to differentiate nasal polyp from turbinate hypertrophy?)
Blob of mucus – disappears on blowing the nose
Angiofibroma – history of recurrent epistaxis
Rhinosporidiosis
Hamartoma
Transitional cell carcinoma
Squamous cell carcinoma
Meningocoele
Other malignancies of nose

Watery discharge from the nose can occur in cases of CSF rhinorrhoea and allergic rhinitis (also in other causes of increased mucus secretion in nose). It is important to differentiate between them so that appropriate treatment can be given.

History

CSF rhinorrhoea – head injury, surgical procedures, intracranial tumours
Allergic rhinitis – sneezing, head cold, itching, lacrimation

When the discharge occurs

CSF rhinorrhoea – when straining or bending forward
Allergic rhinitis – no relation to straining or bending forward, continuous flow

Whether discharge can be sniffed back

CSF rhinorrhoea – cannot be sniffed back
Allergic rhinitis – can be sniffed back

Character …

There are different ways by which the location of leak can be determined in cases of CSF rhinorrhoea.

Injection of dye (flourescein / radioisotope) into intrathecal space and placing cotton pledgets in different parts of nasal cavity. Depending on which pledget gets soaked in the dye, site of leak can be determined

Olfactory cleft – cribriform plate
Sphenoethmoidal recess – Sphenoid sinus
Middle meatus – frontal / ethmoid sinus
Inferior meatus posteriorly near eustachian tube – Temporal bone – reaches via eustachian tube

High resolutaion CT scan – head –  coronal cuts – bone window
CT cisternogram …

Area in the upper part of the nasal cavity near the roof where the olfactory nerve endings are present
In normal respiration, only about 5% of air passes through the olfactory slit area
During deep respiration / sniffing, the proportion of air flowing through the olfactory slit increases and we have improved sense of smell
When we have common cold, mucus gets collected and obstructs the olfactory slit resulting in impaired sense of smell

Synonyms / alternate names:

Olfactory cleft

Otitic hydrocephalus is a condition in which there is increased intracranial tension secondary to acute or chronic middle ear infection.
The CSF shows shows normal levels of protein, glucose and is sterile

Pathogenesis

Middle ear infection can predispose to lateral sinus (transverse sinus) thrombosis
The thrombus can extend into the superior sagittal sinus and impede the drainage of CSF
This results in increased intracranial tension

Clinical features
Features of increased intracranial tension are present:

Headache, nausea, vomiting
Diploplia due to lateral rectus palsy (abducent nerve is usually the first nerve to be affected in increased intracranial tension)
Blurred vision – due to …

Various conditions are considered as possible etiological factors in development of ethmoidal polyps. They are:

Asthma
Chronic rhinosinusitis
Kartagener’s syndrome
Young’s syndrome
Churg Strauss syndrome
Cystic fibrosis
Aspirin intolerance
Allergic fungal sinusitis
Nasal mastocytosis

Sinus of Morgagni is a gap in the upper margin of the pharyngobasilar fascia located in the posterolateral part of the nasopharynx

Pharyngobasilar fascia – also called pharyngeal aponeurosis – is a fibrous layer which lines the internal surface of the muscles of the pharynx and is particularly thick in the upper part – between superior constrictor and the skull base

Structures passing through the Morgagni

Eustachian tube – cartilagenous end
Levator veli palatini muscle
Ascending palatine artery

Clinical importance of sinus of Morgagni

It provides a pathway of least resistance for spread of tumors …

Anterior view of skull – pyriform aperture is highlighted
Click on image for an enlarged view

Pyriform aperture is the anterior most and narrowest area of the bony part of nose
Boundaries of pyriform aperture:

Superior – Nasal bone
Lateral – Frontal (nasal) process of maxilla
Inferior – Premaxilla, anterior nasal spine of maxilla

Clinical importance:

Congenital Nasal Pyriform Aperture Stenosis

stenosis of pyriform aperture resulting in significantly increased nasal airway resistance

CNPAS stands for:

Congenital Nasal Pyriform Aperture Stenosis

AERD stands for:

Aspirin Exacerbated Respiratory Disease