What is the parapharyngeal space?

October 1, 2025 •

4 min read

Approximately 80% of tumors found in the parapharyngeal space are benign, making a proper understanding of what is the parapharyngeal space crucial for diagnosis and treatment. This deep, complex region of the neck contains important neurovascular structures and serves as a key pathway for disease processes.

Quick Summary

The parapharyngeal space is a deep, fat-filled area in the head and neck. Understanding its complex anatomy is vital for diagnosing and treating various pathologies, including rare tumors and serious infections, by analyzing mass displacement on imaging.

Key Points

Inverted Pyramid Shape: The parapharyngeal space is a deep, fat-filled compartment in the neck shaped like an inverted cone, extending from the skull base to the hyoid bone.
Prestyloid vs. Poststyloid: A fascial partition divides the PPS into two compartments; the prestyloid compartment is anterior and contains fat and salivary tissue, while the poststyloid is posterior and contains major neurovascular structures.
Diagnostic Landmark: Radiologists use the displacement of fat within the PPS on imaging (CT/MRI) to accurately determine the origin of a mass in the head and neck.
Primary Tumor Origins: Prestyloid tumors are most commonly from salivary glands (pleomorphic adenomas), while poststyloid tumors are typically neurogenic (schwannomas, paragangliomas).
Risk of Disease Spread: Infections originating from adjacent areas, such as dental sources or the pharynx, can spread into the PPS and lead to serious complications like abscesses or septic thrombosis.
Surgical Challenges: The PPS's deep location and critical contents require expert surgical planning, with approaches chosen based on the tumor's location and characteristics.

Anatomy and Boundaries of the Parapharyngeal Space

The parapharyngeal space (PPS), also known as the lateral pharyngeal or pharyngomaxillary space, is a complex, cone-shaped anatomical compartment deep within the head and neck. It is a potential space, meaning it is not normally open, but filled with loose fat and connective tissue that allows it to act as a central hub for disease spread. The PPS is bordered by several other crucial neck spaces, and its precise location and contents make it significant in both diagnostic imaging and surgical intervention.

The PPS extends from the base of the skull superiorly to the level of the hyoid bone inferiorly. Its boundaries are defined by layers of deep cervical fascia and surrounding structures, including:

Superior: The base of the skull, including parts of the sphenoid and temporal bones, near foramina that transmit important vessels and nerves.
Inferior: The greater cornu of the hyoid bone marks its lower limit.
Medial: The superior constrictor muscle of the pharynx and its overlying buccopharyngeal fascia.
Lateral: The ramus of the mandible, the medial pterygoid muscle, and the deep lobe of the parotid gland.
Posterior: The prevertebral fascia covers the cervical vertebrae and surrounding muscles.

The Two Compartments of the PPS

For diagnostic and surgical purposes, the PPS is divided into two main compartments by the tensor-vascular-styloid fascia (or stylopharyngeal aponeurosis), which extends from the styloid process to the tensor veli palatini muscle. These two compartments are the prestyloid and poststyloid spaces.

Prestyloid Compartment

This is the anterior and lateral portion of the PPS, located in front of the styloid process. It contains primarily fatty tissue and is the site of origin for many salivary gland-related pathologies. Its main contents include:

Adipose (fat) tissue
Deep lobe of the parotid gland
Minor and ectopic salivary glands
Internal maxillary artery and ascending pharyngeal artery branches
Pterygoid venous plexus
Branches of the mandibular nerve (CN V3)
Lymph nodes

Poststyloid Compartment

Also known as the carotid space, this compartment lies behind the styloid process and is home to the major neurovascular structures of the neck. It is the origin for most neurogenic tumors. Its contents include:

Carotid sheath, containing the internal carotid artery and internal jugular vein
Cranial nerves IX, X, XI, and XII
Cervical sympathetic chain
Paraganglia (glomus tissue)
Lymph nodes

Clinical Significance: Tumors and Infections

The PPS's deep location and rich collection of vital structures mean that any pathological process, whether a tumor or an infection, carries significant risk.

Tumors

Tumors within the PPS are rare, making up less than 1% of all head and neck tumors, but they are histologically diverse. About 70-80% are benign. Tumor type often correlates with its compartment of origin:

Prestyloid Tumors: Most frequently salivary gland tumors, with pleomorphic adenoma being the most common.
Poststyloid Tumors: Most are neurogenic tumors, such as schwannomas and paragangliomas, which arise from cranial nerves or the sympathetic chain.

Infections

Infections, or abscesses, in the PPS usually result from the spread of infection from an adjacent space, such as:

Tonsillitis or pharyngitis
Odontogenic (dental) sources
Mastoiditis or otitis media

Symptoms of a PPS abscess include fever, sore throat, dysphagia, trismus (difficulty opening the mouth), and neck swelling. Due to the PPS's communication with other neck spaces, infections can spread rapidly, potentially leading to life-threatening complications like carotid artery rupture or septic jugular vein thrombosis (Lemierre's syndrome).

Diagnosis via Imaging and Fat Displacement

Because the PPS is deeply located and lesions can grow for some time before becoming symptomatic, imaging plays a critical role in diagnosis. MRI is often the preferred modality due to its superior soft tissue contrast, while CT provides better detail on bony structures and calcifications.

Radiologists use the predictable displacement pattern of the PPS fat pad to localize the origin of a mass. This is a crucial diagnostic clue.

Parotid space mass: displaces PPS fat anteromedially.
Masticator space mass: displaces PPS fat posteromedially.
Pharyngeal mucosal space mass: displaces PPS fat posterolaterally.
Poststyloid (carotid space) mass: displaces PPS fat anteriorly.

Comparison of Parapharyngeal Space Compartments


Feature	Prestyloid Compartment	Poststyloid Compartment
Location	Anterolateral to styloid process	Posterolateral to styloid process
Predominant Content	Fat, deep lobe of parotid gland	Neurovascular bundle (carotid sheath)
Common Benign Tumors	Pleomorphic adenoma (salivary)	Schwannomas, paragangliomas (neurogenic)
Mass Displacement	Pushes internal carotid artery posteromedially	Pushes internal carotid artery anteromedially
Infection Sources	Dental, salivary gland	Cranial nerve, vascular
Primary Nerve	Mandibular nerve (V3) branches	Cranial Nerves IX, X, XI, XII

Treatment Approaches and Complications

For most PPS tumors, complete surgical excision is the primary treatment. The surgical approach is tailored to the tumor's size, location, and nature (benign vs. malignant). Surgical approaches include transcervical (most common for benign tumors), transparotid-transcervical (for deep-lobe parotid tumors), transoral (for small, accessible tumors), and transmandibular (for larger or malignant tumors). Complications can include damage to cranial nerves, leading to issues like hoarseness or facial palsy. Preserving nerves is especially important with neurogenic tumors. A less common complication is first bite syndrome, causing facial pain upon the first bite of food, potentially due to autonomic nerve damage.

Conclusion

The parapharyngeal space is a critical but often overlooked region of the head and neck, primarily understood by otolaryngologists and radiologists. While pathologies affecting this space are relatively rare, its strategic location near major neurovascular structures means that both tumors and infections present significant diagnostic and therapeutic challenges. Through advanced imaging techniques, clinicians can accurately pinpoint the source of a lesion by observing the displacement of the PPS fat. Ultimately, effective management requires careful assessment, skilled surgical planning, and a deep understanding of this complex anatomical area. Link to resource: The National Institutes of Health (NIH) provides extensive peer-reviewed literature on PPS tumors and their management.

Frequently Asked Questions

The parapharyngeal space is a potential space, meaning it doesn't have a specific physiological function like an organ. Its main role is to provide a pathway for important nerves and vessels to pass through the neck and skull base. It is mostly filled with loose fatty tissue.

Diagnosis primarily relies on imaging. Computed tomography (CT) scans and magnetic resonance imaging (MRI) are used to visualize the mass and determine its relationship to surrounding structures. A key sign is the predictable displacement of the PPS's fat pad by the tumor, which helps pinpoint its origin.

No, most tumors found in the parapharyngeal space are benign. Studies show that about 70-80% of PPS tumors are non-cancerous. However, both benign and malignant tumors can occur, and evaluation is needed to determine the type.

Many masses in this area are asymptomatic until they grow large enough to cause problems. Common symptoms can include a neck mass, a bulge in the throat (oropharyngeal swelling), or dysphagia (difficulty swallowing). Infections often cause fever, sore throat, and neck stiffness.

Yes. The PPS is continuous with several other neck spaces, including the retropharyngeal and submandibular spaces. This anatomical connection means infections can spread rapidly and potentially lead to severe complications, such as a carotid artery blowout or jugular vein thrombosis.

The main difference is their origin and location. Prestyloid tumors arise from the anterior compartment, often from salivary glands (e.g., pleomorphic adenomas). Poststyloid tumors arise from the posterior, neurovascular compartment, typically from nerves or paraganglia (e.g., schwannomas).

First Bite Syndrome is a rare complication that can occur after surgery involving the parapharyngeal space, particularly the parotid gland. It causes severe pain or cramping in the facial region upon the first bite of a meal, which typically subsides as the meal progresses.