Pharyngeal mucosal space and lesions affecting it

Introduction:

Pharyngeal mucosal space is the area of nasopharynx and oropharynx on the inner (airway) side of the buccopharyngeal fascia. This buccopharyngeal fascia separates the pharyngeal mucosal space from the parapharyngeal space laterally and the retropharyngeal space posteriroly.

The pharyngeal mucosal space is composed of 5 layers forming the walls of pharynx. From inside to outside these layers are:

1. Mucous membrane: The upper part of nasopharynx is lined by respiratory epithelium, and inferiorly where food comes into constant contact the epithelium transforms to stratified squamous.
2. Submucosa: Contains modified minor salivary glands and prominent lymphoid tissue of waldayer's ring. Lymphoid tissue may also be present normally in the epithelium
3. Dense pharyngobasilar fascia
4. Superior constrictor muscle of pharynx, above this muscle the layers 3 and 5 are adherent. This area is pierced by the eustachean tube and levator palatini muscle
5. Thin buccopharyngeal fascia forms the lateral most outer layer of this space

It descends from the skull base down to the level of cricoid cartilage. It lies medial to the hyoid bone and lateral to the pharyngeal wall.

Contents:

Pharyngeal constrictors and elevators

Eustachean tube

Minor salivary glands

Lymphoid tissue

Axial CT Neck showing abscess in the pharyngeal mucosal space.

Note the presence of gas shadow which is significant