NEXT STOP : Central Station "Pterygopalatine fossa"

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1 NEXT STOP : Central Station "Pterygopalatine fossa" Poster No.: C-1359 Congress: ECR 2015 Type: Educational Exhibit Authors: I. Alba de Caceres, A. Paniagua, L. Ibañez, J. A. Blanco ; Madrid/ES, Parla(Madrid)/ES Keywords: Cancer, elearning, Comparative studies, MR, CT, Head and neck, Ear / Nose / Throat, Anatomy, Inflammation, Neoplasia DOI: /ecr2015/C-1359 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 53

2 Learning objectives -To have a well knowledge of the anatomical space of Pterygopalatine Fossa, and all of the variety of fissures, foramina and Canals that put it in communication with the rest of Craniofacial cavities. -To review the pathology that affects this area and its mechanisms of spread, focusing especially on the perineural spread, since through the nerves that run through the canals and foramina, gets more in evidence the anatomic relationship of the PFF, with the rest of cavities Background The PPF is a small anatomic space in the skull base, shaped like an inverted pyramid, located behind the maxilla and ahead of the pterygoid apophyses, lateral to the nasal cavity, medial to the masticator space, and at a lower level to orbital apex. Its content is mostly fat, which is very important from the point of view of the image; since the involvement of this space, can be appreciated quickly,in both CT and MRI, for effacement of such content. In addition, it is a crucial space passing through various nerves, veins and arteries, exerting as a central station along which several "trains" runs in different directions, through different paths; fissures, canals and foraminas, that put in communication with the other cavities. The PPF is the biggest distribution center for parasympathetic innervation and blood supply of the deeper facial structures. For all those reasons, the knowledge of its anatomy is essential. Local tumors, tumor extension from adjacent areas, perineural spread of malignant tumors, are the pathology most frequently affects this space. We can not forget benign inflammatory processes, both,autoimmune diseases & infectious (paranasal or odontogenic origin). Fractures of the maxilla & orbit, in a high-impact trauma, mainly the Le Fort type I and II, can affect also the pterygopalatine fossa Page 2 of 53

3 Fig. 1: 3D image of the lateral craniofacial view ; has been removed the zygomatic arch to assess properly the pterygopalatine fossa, which is shown in the box, with an inverted pyramid shaped.it adjoins ahead with the rear face of the maxilla and behind with the plate of the pterygoid apophysis. At the bottom you can see its communication with the nasal cavity through the sphenopalatine foramen and inside a vascular structure (arrow) it is the pterygopalatine artery, third portion of the maxillary artery. References: Hospital Infanta Sofía, UCR, Madrid,Spain Images for this section: Page 3 of 53

4 Fig. 1: 3D image of the lateral craniofacial view ; has been removed the zygomatic arch to assess properly the pterygopalatine fossa, which is shown in the box, with an inverted pyramid shaped.it adjoins ahead with the rear face of the maxilla and behind with the plate of the pterygoid apophysis. At the bottom you can see its communication with the nasal cavity through the sphenopalatine foramen and inside a vascular structure (arrow) it is the pterygopalatine artery, third portion of the maxillary artery. Page 4 of 53

5 Findings and procedure details NORMAL ANATOMY As previously has beeen mentioned, it is a space located at the base of the skull with an inverted pyramid shape, whose main content is fat, and along which runs many nerves and vessels. Lies behind the posterior wall of the maxillary sinus, and its posterior border is formed by the fused of themedial and lateral pterygoid plates The walls or borders of the PPF are as follows: MEDIAL-Perpendicular plate palatine border LATERAL-Pterygomaxillary fissure ANTERIOR-Posterior wall of maxillary sinus POSTERIOR-Medial and Lateral Pterygoid wings SUPERIOR - Inferior orbital fissure INFERIOR- Palatine canals Page 5 of 53

6 Fig. 2: PPF (PTERYGOPALATINE FOSSA), asterisk, as an inverted pyramid shape, behind the posterior wall of the maxillary sinus ( arrow head) and ahead of the fusion of the lateral and medial pterygoid wings (arrow) References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 6 of 53

7 Fig. 3: The main content is fat, note the low density of Hounsfield Units. The medial wall is the PPP References: Hospital Infanta Sofía, UCR, Madrid,Spain The PPF communicates with other cavities: ANTERIORLY - The PPF communicates with the orbit by the inferior orbital fissure. POSTERIORLY AND SUPERIORLY - Communicates with middle cranial fossa through the foramen rotundum by passing the second branch of the V cranial nerve, maxillar nerve, which is,retrogradely,directed the cavernous sinus and Meckel's cave. The V cranial nerve runs along the top of FPP, above the sphenopalatine ganglion, then is where gives the various branches POSTERIORLY AND INFERIORLY - Communicates with the middle cranial fossa through vidian or pterygoid canal, through which runs the vidian nerve, it is the union Page 7 of 53

8 of the petrous superficial nerve (branch of the facial with parasympathetic and motor fibers) & deep petrous nerve (plexus of the sympathetic branch of the ICA) and ends at sphenopalatine ganglion ( it is inside of the PPF ). The vidian canal connects the PPF with the foramen lacerum. Medially to the vidian foramen is the pharyngeal or palatinovaginal canal, transmits the pharyngeal nerve LATERALLY - communicates with the masticator space or infratemporal fossa through the fissure pterigomaxillary MEDIALLY - Communicates with the nasal cavity through the sphenopalatine foramen which transmits the sphenopalatine artery & the nasopalatine nerve ; branch of the maxillary cranial nerve. SUPERIORLY - PPF is connected to the orbital apex through to the posteromedial aspect of the infraorbital fissure. INFERIORLY - PPF connects with the oral cavity by the greater and lesser palatine canals, transmitting their respective nerves ( branches of the maxillary nerve ) and arteries. Page 8 of 53

9 Fig. 8: NORMAL GROSS ANATOMY- Communications, borders & foramen-canals. SUPERIOR BOUNDARY References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 9 of 53

10 Fig. 4: NORMAL GROSS ANATOMY- Communications, borders & foramencanals.posterior & SUPERIOR BOUNDARY References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 10 of 53

11 Fig. 5: NORMAL GROSS ANATOMY- Communications, borders & foramen-canals. POSTERIOR BOUNDARY References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 11 of 53

12 Fig. 6: NORMAL GROSS ANATOMY- Communications, borders & foramencanals.lateral BOUNDARY References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 12 of 53

13 Fig. 7: NORMAL GROSS ANATOMY- Communications, borders & foramen-canals. MEDIAL BOUNDARY References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 13 of 53

14 Fig. 8: NORMAL GROSS ANATOMY- Communications, borders & foramen-canals. SUPERIOR BOUNDARY References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 14 of 53

15 Fig. 9: NORMAL GROSS ANATOMY- Communications, borders & foramen-canals. INFERIOR BOUNDARY References: Hospital Infanta Sofía, UCR, Madrid,Spain 5 regions with which PPF communicates: 1- Nasal Fossae by sphenopalatine foramen 2-Oral cavity by pterygopalatine ducts and palatine foramines 3-Infratemporal fossae ( masticator space ) by pterigomaxilar fissure 4-Orbit through inferior orbital fissure. 5-MCF through the rotundum foramen and through the vidian or pterygoid canal. CONTENT Page 15 of 53

16 Fat Sphenopalatine or pterygopalatine ganglion, provides parasympathetic innervation to: pharynx, palate, nasal cavity and lacrimal gland.ganglion hangs up by the pterygopalatine nerves of themaxillar nerve (Vb) and of the lower ganglion hangs the major and minor palatine nerves.get out of the back face of ganglion, the petrosal nerves to form the vidian, and also leaves in the front, nasal nerves to the turbinates. Nerves : Vb BRANCHES Nasopalatine nerve, which enters the sphenopalatine foramen and gives septal and nasal cavity branches. Infraorbital nerve, passes through inferior orbital fissure, runs parallel to the floor of the orbit and enters into the infraorbital foramen. Posterior & superior alveolar nerve, maxillary enter through hole. Greater and Lesser palatine nerve fall by two palatine canals. Arteries : MAXILLARY ARTERY BRANCHES Sphenopalatine artery Infraorbital artery Descending palatine artery 2. Pathological Processes TUMORAL INFECTIOUS TRAUMATIC MALIGNANT TUMORS Page 16 of 53

17 -Squamous cell carcinoma (sinus & nasopharynx), adenocarcinoma, melanoma, rhabdomyosarcoma, and infrequent esthesioneurobiastoma may involve the FPP, by direct extension -Metastatic bone lesions are rare. RCC, breast, lung and melanoma. -Lymphoma -Perineural spread of squamous cell carcinoma and adenoid cystic carcinomas in nasopharynx, in major and minor -accessory salivary glands, and also in paranasal sinuses. IMAGING METHODS in malignant lesions MR - technique of choice to assess tumor extension CT -appreciates fine shape and size of the foramen and canals as well as the possible destructive pattern of injuries. PET-CT. Far superior to CT and MRI in detecting residual and recurrent tumor pathology and to study lymph node involvement (in cases) PERINEURAL SPREAD -Full Enhance the entire circumference of the nerve (T1 + GD) -Erasure or obliteration of all fatty yuxtaforaminales parcels -Increase the size of the foramen & canals. -Extension to intracraneal- compartment (cisternal, dural enhancements, occupation cavernous sinus) -Neural involvement produces muscle denervation atrophy (more common in masticator muscle (Vc ccnn) and tongue (XII ccnn). Acute denervation (first month) shows edema and enhancement. Chronic denervation shows muscular atrophy with fat replacement Page 17 of 53

18 Fig. 10: Woman of 92 years with symptoms of diplopia and oculomotor paresis of cranial nerves. Occupying lesion in the PPF ; note in skull CT asymmetry of the right side with respect to fat left side (arrow in A). In T1 enhanced axial plane with fat suppression (B ), an injury that captures contrast and extending perineural spread from Meckel's cave by right cavernous sinus and leaves the foramen rotundum (yellow circle) to occupy PPF. In coronal plane ( D ), shown as the perineural spread spans the V c ( blue arrow ) through the foramen ovale (yellow circle). At a lower axial plane ( C ), the consequences of acute denervation is demonstrated, as edema in the masticatory muscles and medial and lateral (yellow asterisk) pterygoid muscles. The lesion was lymphoma References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 18 of 53

19 Fig. 11: Woman of 92 years with symptoms of diplopia and oculomotor paresis of cranial nerves. Occupying lesion in the PPF ; note in skull CT asymmetry of the right side with respect to fat left side (arrow in A). In T1 enhanced axial plane with fat suppression (B ), an injury that captures contrast and extending perineural spread from Meckel's cave by right cavernous sinus and leaves the foramen rotundum (yellow circle) to occupy PPF. In coronal plane ( D ), shown as the perineural spread spans the V c ( blue arrow ) through the foramen ovale (yellow circle). At a lower axial plane ( C ), the consequences of acute denervation is demonstrated, as edema in the masticatory muscles and medial and lateral (yellow asterisk) pterygoid muscles. The lesion was lymphoma References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 19 of 53

20 Fig. 12: Neck enhanced CT in 51 year old male with a history of palate cylindroma, which currently has a mass at that location. In A, sagittal reconstruction, the lesion (yellow arrow) extending into nasal cavity, and from there, by the sphenopalatine foramen into the left PPF (arrow in B) is appreciated. It was a second malignancy, adenoid cystic carcinoma References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 20 of 53

21 Fig. 13: Neck CT with contrast in a 60 years old man, with mass in nasopharynx (Asterisk in A), which was an epidermoid carcinoma, extending to both PPF from the nasal cavity (blue arrows in B), and secondary involvement, by perineural spread, of the left middle cranial fossa, through the foramen rotundum by Vb (double arrow B). From the PPF, there is also a perineural spread into orbit by the superior orbital fissure, probably through the infraorbital nerve (double arrow in C) dissemination. Vc is also affected, yellow circle in D References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 21 of 53

22 Fig. 14: Neck CT with contrast in a 60 years old man, with mass in nasopharynx (Asterisk in A), which was an epidermoid carcinoma, extending to both PPF from the nasal cavity (blue arrows in B), and secondary involvement, by perineural spread, of the left middle cranial fossa, through the foramen rotundum by Vb (double arrow B). From the PPF, there is also a perineural spread into orbit by the superior orbital fissure, probably through the infraorbital nerve (double arrow in C) dissemination. Vc is also affected, yellow circle in D References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 22 of 53

23 Fig. 15: Meningioma with malignant transformation of supraclinoid location (asterisk in C) having a local invasion and bone destruction extension to the PPF Right (yellow circle in A), where there a widening of the fossa is shown, and also in the the sphenopalatine foramen. The injury also extends through the meninges that covers the right optic nerve (double arrow B). References: Hospital Infanta Sofía, UCR, Madrid,Spain BENIGN LESIONS -Inverted papilloma - appears as a unilateral mass or soft tissue, bone accompanied by bone expanding and/or focal destruction. -Nasopharyngeal angiofibroma It is a male teenager vascular lesion that typically passes from nasal cavity to the FPP by the sphenopalatine foramen -Pituitary adenomas, trigeminal neurinomas, meningiomas. Page 23 of 53

24 -No tumor benign lesions such as giant aneurysm of the intracavernous carotid artery can cause erosion of the sphenoid sinus. If the aneurysm is of sufficient size, the destruction of bone may extend to the base of the pterygoid process. -Fibrous dysplasia may involve several bones of the facial skeleton and anterior cranial fossa. Fig. 18: 16 years old man, with epistaxis. Vascularized mass with focis of signal void vascular elements ; mass is hyperintense on T2 and hypointense on T1, with great contrast enhancement. It was a juvenile nasopharyngeal angiofibroma, which typically enters into the PPF through the sphenopalatine foramen References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 24 of 53

25 Fig. 19: Tumor recurrence / Remnants of a juvenile nasopharingeal angiofibroma in a male patient 32 year old, operated 16 years ago. The lesion occupies the PPF (red square in A) and widens the sphenopalatine foramen (yellow arrow in B). References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 25 of 53

26 Fig. 20: Young woman with left proptosis, which has a lesion in greater wing of the sphenoid with bone enlargement (arrow in B) and growth of intra- and extracranial mass of soft tissue. In A, growth in the masticator space and PPF, star and circle respectively shown. In B is shown intracranial growth. It was a typical meningioma WHO grade I References: Hospital Infanta Sofía, UCR, Madrid,Spain Page 26 of 53

27 Fig. 21: Young woman with epilepsy, temporal probable origin. In MRI lesion suggestive of congenital arachnoid cyst is seen on the left side, with bone dehiscence on the floor of the middle cranial fossa, extending to the PPF. In A cystic lesion was hyperintense appearance seen in T2.En B absence of enhancement is appreciated. References: Hospital Infanta Sofía, UCR, Madrid,Spain INFECTIONS -Infectious lesions of the nose and sinuses uncomplicated, NEVER affect PPF. -Chronic polyposis presents with mucosal hypertrophy and erosion and / or bone sclerosis, but DOES NOT affect the PPF. -Necrotizing granulomas, eg Wegener and fungal infections, they can affect the PPF, Associated bone destruction without expansion.several paranasal sinuses are usually involved and bone destruction initially tends to follow the natural foramina and fissures. -Mucocele sphenoethmoidal can involve the FPP. Page 27 of 53

28 Fig. 22: 32 man with cranial multineuritis; involvement of multiple cranial nerve, motor and sensory. An affectation of the nasopharynx (asterisk), with extension to the PPF sphenopalatines foramina bilaterally. (Yellow circles) From there, an extension to respective spaces craneal middle fossa through the foramen rotundum (arrow in A) are also appreciated. It was a necrotizing granulomatosis of Wegener. References: Hospital Infanta Sofía, UCR, Madrid,Spain TRAUMATISM -In severe facial trauma, usually involving the pterygoid procese. -In fractures of the zygomatic-maxillary complex and LeFort fractures, frontal or lateral forces can break maxillary pterygoid, because they are partially fused. -Le Fort I and II, extending through the pterygomaxillary fissure widening the FPP affecting the lower edge of the pterygoid laminae Page 28 of 53

29 -Le Fort III, interrupt the apophyses near the apex of the pyramid of FPP -CT is the imaginng method of choice. Fig. 23: A - 3D craniofacial reconstruction ; where Le-Fort type II fracture is appreciated. In B can be seen a fracture of the posterior border of the maxillary sinus with secondary affectation of PPF (arrow) References: Hospital Infanta Sofía, UCR, Madrid,Spain Images for this section: Page 29 of 53

30 Fig. 2: PPF (PTERYGOPALATINE FOSSA), asterisk, as an inverted pyramid shape, behind the posterior wall of the maxillary sinus ( arrow head) and ahead of the fusion of the lateral and medial pterygoid wings (arrow) Page 30 of 53

31 Fig. 4: NORMAL GROSS ANATOMY- Communications, borders & foramencanals.posterior & SUPERIOR BOUNDARY Page 31 of 53

32 Fig. 9: NORMAL GROSS ANATOMY- Communications, borders & foramen-canals. INFERIOR BOUNDARY Page 32 of 53

33 Fig. 8: NORMAL GROSS ANATOMY- Communications, borders & foramen-canals. SUPERIOR BOUNDARY Page 33 of 53

34 Fig. 7: NORMAL GROSS ANATOMY- Communications, borders & foramen-canals. MEDIAL BOUNDARY Page 34 of 53

35 Fig. 5: NORMAL GROSS ANATOMY- Communications, borders & foramen-canals. POSTERIOR BOUNDARY Page 35 of 53

36 Fig. 6: NORMAL GROSS ANATOMY- Communications, borders & foramencanals.lateral BOUNDARY Page 36 of 53

37 Fig. 3: The main content is fat, note the low density of Hounsfield Units. The medial wall is the PPP Page 37 of 53

38 Fig. 10: Woman of 92 years with symptoms of diplopia and oculomotor paresis of cranial nerves. Occupying lesion in the PPF ; note in skull CT asymmetry of the right side with respect to fat left side (arrow in A). In T1 enhanced axial plane with fat suppression (B ), an injury that captures contrast and extending perineural spread from Meckel's cave by right cavernous sinus and leaves the foramen rotundum (yellow circle) to occupy PPF. In coronal plane ( D ), shown as the perineural spread spans the V c ( blue arrow ) through the foramen ovale (yellow circle). At a lower axial plane ( C ), the consequences of acute denervation is demonstrated, as edema in the masticatory muscles and medial and lateral (yellow asterisk) pterygoid muscles. The lesion was lymphoma Page 38 of 53

39 Fig. 11: Woman of 92 years with symptoms of diplopia and oculomotor paresis of cranial nerves. Occupying lesion in the PPF ; note in skull CT asymmetry of the right side with respect to fat left side (arrow in A). In T1 enhanced axial plane with fat suppression (B ), an injury that captures contrast and extending perineural spread from Meckel's cave by right cavernous sinus and leaves the foramen rotundum (yellow circle) to occupy PPF. In coronal plane ( D ), shown as the perineural spread spans the V c ( blue arrow ) through the foramen ovale (yellow circle). At a lower axial plane ( C ), the consequences of acute denervation is demonstrated, as edema in the masticatory muscles and medial and lateral (yellow asterisk) pterygoid muscles. The lesion was lymphoma Page 39 of 53

40 Fig. 12: Neck enhanced CT in 51 year old male with a history of palate cylindroma, which currently has a mass at that location. In A, sagittal reconstruction, the lesion (yellow arrow) extending into nasal cavity, and from there, by the sphenopalatine foramen into the left PPF (arrow in B) is appreciated. It was a second malignancy, adenoid cystic carcinoma Page 40 of 53

41 Fig. 13: Neck CT with contrast in a 60 years old man, with mass in nasopharynx (Asterisk in A), which was an epidermoid carcinoma, extending to both PPF from the nasal cavity (blue arrows in B), and secondary involvement, by perineural spread, of the left middle cranial fossa, through the foramen rotundum by Vb (double arrow B). From the PPF, there is also a perineural spread into orbit by the superior orbital fissure, probably through the infraorbital nerve (double arrow in C) dissemination. Vc is also affected, yellow circle in D Page 41 of 53

42 Fig. 14: Neck CT with contrast in a 60 years old man, with mass in nasopharynx (Asterisk in A), which was an epidermoid carcinoma, extending to both PPF from the nasal cavity (blue arrows in B), and secondary involvement, by perineural spread, of the left middle cranial fossa, through the foramen rotundum by Vb (double arrow B). From the PPF, there is also a perineural spread into orbit by the superior orbital fissure, probably through the infraorbital nerve (double arrow in C) dissemination. Vc is also affected, yellow circle in D Page 42 of 53

43 Fig. 15: Meningioma with malignant transformation of supraclinoid location (asterisk in C) having a local invasion and bone destruction extension to the PPF Right (yellow circle in A), where there a widening of the fossa is shown, and also in the the sphenopalatine foramen. The injury also extends through the meninges that covers the right optic nerve (double arrow B). Page 43 of 53

44 Fig. 16: 84 years old male, with exophthalmos and diplopia, which is diagnosed with squamous cell carcinoma nonkeratinizing extending perineural spread to middle cranial fossa and orbit coming through the infraorbital nerve to cheek, where biopsy was performed. In A mass seen on CT neck, PPF and left masticator space. In C, the lesion extends into orbit by the lower orbital fissure. In B the injury that has advanced by the infraorbital nerve with subcutaneous soft tissue mass in cheek MRI showed an invasion of the middle cranial fossa, cavernous sinus and Meckel cavum left (yellow circle in D & E). Metastatic dural enhancement is seen (double arrow in D) Page 44 of 53

45 Fig. 17: 84 years old male, with exophthalmos and diplopia, which is diagnosed with squamous cell carcinoma nonkeratinizing extending perineural spread to middle cranial fossa and orbit coming through the infraorbital nerve to cheek, where biopsy was performed. In A mass seen on CT neck, PPF and left masticator space. In C, the lesion extends into orbit by the lower orbital fissure. In B the injury that has advanced by the infraorbital nerve with subcutaneous soft tissue mass in cheek MRI showed an invasion of the middle cranial fossa, cavernous sinus and Meckel cavum left (yellow circle in D & E). Metastatic dural enhancement is seen (double arrow in D) Page 45 of 53

46 Fig. 18: 16 years old man, with epistaxis. Vascularized mass with focis of signal void vascular elements ; mass is hyperintense on T2 and hypointense on T1, with great contrast enhancement. It was a juvenile nasopharyngeal angiofibroma, which typically enters into the PPF through the sphenopalatine foramen Page 46 of 53

47 Fig. 19: Tumor recurrence / Remnants of a juvenile nasopharingeal angiofibroma in a male patient 32 year old, operated 16 years ago. The lesion occupies the PPF (red square in A) and widens the sphenopalatine foramen (yellow arrow in B). Page 47 of 53

48 Fig. 20: Young woman with left proptosis, which has a lesion in greater wing of the sphenoid with bone enlargement (arrow in B) and growth of intra- and extracranial mass of soft tissue. In A, growth in the masticator space and PPF, star and circle respectively shown. In B is shown intracranial growth. It was a typical meningioma WHO grade I Page 48 of 53

49 Fig. 21: Young woman with epilepsy, temporal probable origin. In MRI lesion suggestive of congenital arachnoid cyst is seen on the left side, with bone dehiscence on the floor of the middle cranial fossa, extending to the PPF. In A cystic lesion was hyperintense appearance seen in T2.En B absence of enhancement is appreciated. Page 49 of 53

50 Fig. 22: 32 man with cranial multineuritis; involvement of multiple cranial nerve, motor and sensory. An affectation of the nasopharynx (asterisk), with extension to the PPF sphenopalatines foramina bilaterally. (Yellow circles) From there, an extension to respective spaces craneal middle fossa through the foramen rotundum (arrow in A) are also appreciated. It was a necrotizing granulomatosis of Wegener. Page 50 of 53

51 Fig. 23: A - 3D craniofacial reconstruction ; where Le-Fort type II fracture is appreciated. In B can be seen a fracture of the posterior border of the maxillary sinus with secondary affectation of PPF (arrow) Page 51 of 53

52 Conclusion The PPF is a very small area at the base of the skull, which three arteries and nerves by putting the different craniofacial cavities in communication. The knowledge of its location and anatomy;boundaries as well as input-output pathways, and structures that run through it, are crucial to interpret and correlate the clinical findings, mainly by neurological involvement of cranial nerves. For this reason, it is very important to learn about their anatomy and the different pathological processes that may affect it Personal information ignacio.alba@salud.madrid.org References Curtin HD, Williams R, Johnson J. CT of perineural tumor extension: pterygopalatine fossa. AJNR Am J Neuroradiol 1984;5: Caldemeyer KS, Mathews VP, Righi PD, Smith RR. Imaging features and clinical significance of perineural spread or extension of head and neck tumors. Radiographics 1998;18: Daniels DL, Mark LP, Ulmer JL, et al. Anatomic moment: osseus anatomy of the pterygopalatine fossa. AJNR Am J Neuroradiol 1998;19: Ling-Ling Chan, June Chong, Ann M. Gillenwater, and Lawrence E. Ginsberg, The Pterygopalatine Fossa: Postoperative MR Imaging Appearance.AJNR Am J Neuroradiol, 21: , August 2000 Page 52 of 53

53 Radiology of the Pterygoid Plates and Pterygoid fossa. AJR 132: ,March 1979 Page 53 of 53