The parapharyngeal space is shaped like an inverted pyramid with its base at the skull base and apex pointing to the hyoid bone. It is separated into prestyloid and poststyloid spaces. Common contents include the internal carotid artery, internal jugular vein, cranial nerves 9-12, and cervical sympathetic chain. Lesions in this space can cause neck masses, pharyngeal masses, dysphagia, and cranial nerve deficits. Pleomorphic adenomas most commonly involve the prestyloid compartment while neurogenic tumors more commonly involve the poststyloid compartment.

2. • The parapharyngeal space is shaped like a
pyramid, inverted with its base at the skull base,
with its apex inferiorly pointing to the greater
cornu of the hyoid bone .

3. •The fascia of the stylopharyngeus, styloglossus,
and tensor veli palatini muscles separates
prestyloid and poststyloid spaces
•styloid process

6. • Superior margin: base of skull
• Inferior : greater cornu of the hyoid bone
• Medial : middle layer of deep cervical fascia
• Lateral : investing fascia covering the deep lobe
of the parotid
• Anterior : investing fascia covering the medial
pterygoid
• Posterior : prevertebral fascia

7. •1. internal maxillary artery
•2. inferior alveolar nerve
•3. lingual nerve
•4. auriculotemporal nerve

8. • Contents of carotid sheath –>internal carotid
artery, internal jugular vein, and cranial nerves 9,
10 and 12.
• Cervical sympathetic chain
• Numerous lymph nodes

12. • Spread of adjacent tumors -nasopharyngeal and
oropharyngeal carcinoma, chordoma, and synovial
sarcoma
• Minor salivary gland tumors -pleomorphic adenoma
• Neurogenic tumors
• Lymph nodes
• Paragangliomas
• Parapharyngeal space abscess
• Parotid deep lobe tumors
• Branchial cleft cysts

13. CAROTID ARTERY
•Ectasia
•Aneurysm
•Dissection
•Encasement by direct squamous cell carcinoma.

14. • Asymmetric enlargement
• Thrombosis
• Thrombophlebitis
• Meningioma (from jugular foramen)

15. • Neurogenic Tumor
• Neuroblastoma
• Paraganglioma

16. • Neck mass
• Oropharyngeal mass
• Unilateral eustachian tube dysfunction
• Dysphagia
• Dyspnea
• Obstructive sleep apnea
• CN deficits
• Horner syndrome
• Pain
• Trismus
• Symptoms of catecholamine excess

17. Localizing the lesion

18. • Displacement of the lateral wall of the
pharyngeal space medially,
• Displacement of the parotid gland laterally while
maintaining an inta c t fa t p la ne with the deep lobe
of parotid gland
• Displacement of the carotid vessels posteriorly

19. • Anterolateral displacement of the prestyloid
parapharyngeal fat.
• Anterior or medial displacement of the internal
carotid artery with o blite ra tio n o f fa t p la ne s
around the great vessels.
• Extension posterior to the styloid process with
its anterolateral displacement.

20. Pleomorphic adenoma in a 35 yr-old-woman. Contrast enhanced axial
CT scan shows a minimally enhancing water attenuation well-defined
mass extending into the prestyloid parapharyngeal space with
widening of the stylomandibular tunnel.

21. • Prestyloid/pos
tstyloid
compartment?

22. Axial unenhanced T1-weighted spin-echo MR image shows low-signal-intensity
mass . Medial fat line between mass and pharyngeal mucosa
is displaced but preserved, whereas lateral fat line between mass and
parotid gland is not seen, indicating parotid origin.

23. Contrast enhanced axial CT scan shows a heterogeneously
enhancing Schwannoma with areas of necrosis displacing the
internal carotid artery anteromedially.

24. Neurofibroma in a 22yr-old-man. Contrast enhanced axial CT
scan shows the minimally enhancing tumor in the post-styloid
space causing anterior displacement of ICA

25. • Presence of internal flow voids on MR Imaging in
a mass that is greater than 2 cm is suggestive of
paraganglioma, rather than Schwanoma.

26. Carotid body tumor in a 26 yr-old-man.

27. Post contrast axial CT shows intensely enhancing vagale tumor
causing anterior displacement of the internal carotid artery

28. Malignant peripheral nerve sheath tumor Axial T2-weighted
spin-echo MR image shows tumor (arrows) is slightly
hyperintense to muscle

29. tumor (arrows) extends into eustachian tube
(arrowheads).

30. Immediately life threatening
lesion ??

31. Skull base extension of the meningioma seen as hyperostosis of
the adjacent skull base with a small calcified intracranial
infratentorial component

32. Tumor causing smooth
scalloping and widening of
jugular foramen ??
s c hwanoma

33. Post contrast Axial CT shows a peripherally enhancing
right parapharyngeal abscess with air pockets

34. Tubercular lymphadenitis

35. Metastatic lymphnodes

36. • Pleomorphic adenoma is the most common tumor
involving the p re s ty lo id compartment.
• Neurogenic tumors commonly involve the p o s ts ty lo id
compartment.

37. Thank you