Juvenile nasopharyngeal angiofibroma

nasopharynx
pterygopalatine fossa
first brachial arc theory
ramharan sign
chopstick sign

1. Juvenile Nasopharyngeal Angiofibroma Ashish k.Gupta SMS medical college J aipur

2. Introduction Juvenile angiofibroma is an uncommon, benign and extremely vascular tumour

3. History  Juvenile nasopharyngeal angiofibroma has been documented since the time of Hippocrates (4 BC).   Infact Hippocrates goes on to describe a polyp in the nose which weeped blood.  Shaheen in 1930 reported the first female patient with juvenile nasopharyngeal angiofibroma .  Friedberg first used the term angiofibroma in 1940.  Hondousa recorded the youngest JNA patient (8 years).  Figi and Davis (1950) emphasised the role of surgery in the management of JNA. 

4. Epidemiology Frequency <0.5% of all head and neck tumors. A frequency of 1:5,000-1:60,000 in otolaryngology patients has been reported. Sex- Occurs exclusively in males. Age- Onset is most commonly in the second decade; the range is 7-19 years. Rare in patients older than 25 years.

5. Anatomy

6. Nasopharynx This area  has been considered as an antomical blind spot (a virtual no man's land) because of its relative inaccessible It is an unyielding irregular cuboidal box containing 4 x 3 x 2 cm air space at the base of middle cranial fossa . 

7. Boundaries of Nasopharynx : Anterior : Choanal orifice and posterior margin of nasal septum. Floor: Anterior the upper surface of soft palate in its Posteriorly , the floor is deficient where the nasopharynx communicates inferiorly with the oropharynx through the pharyngeal isthmus. Roof and posterior wall: continuous sloping surface of the body of the sphenoid, the basiocciput and the first two cervical vertebrae up to the level of the soft palate. 

8. Lateral wall: is dominated by the pharyngeal end of eustachian tube.  Behind the posterior margin of torus, between it and the posterior wall lies the lateral pharyngeal recess or the fossa of  Rosenmuller .  The upper portion of the posterior wall lies in front of the anterior arch of atlas with a mass of lymphoid tissue embedded in the mucous membrane (adenoid). 

9. Pterygopalatine Fossa Bony inverted tear drop space. Contains- Maxillary nerve Maxillary Artery Pterygopalatine Ganglion

10. Etiopathogenesis

11. Ringertz theory: (1938)He believed that JNA always arise from the periosteum of the skull base. Marten et al (1948): Proposed a hormonal theory suggesting that these tumors resulted from deficiency of androgens or over activity of estrogens and that the hormonal stimulation is responsible for angiomatous components seen in JNA tissue. Sternberg (1954): Proposed that JNA could be a type of haemangioma like a cutaneous haemangioma seen in children which regresses with age.

12. Osborn (1959): Considered two alternatives to explain the etiology of JNA.  They proposed that the swelling could be due to either a hamartoma or residual fetal erectile tissue which were subject to hormonal influences. Girgis & Fahmy (1973): Observed cell nests of undifferentiated epitheloid cells or "Zell ballen " at the growing edge of angiofibromas .  This appearance was more or less similar to that of paraganglioma .  They considered JNA to be a paraganglionoma .   The most accepted theory is that JNAs originate from sex steroid–stimulated hamartomatous tissue located in the turbinate cartilage.

13. 1. Sex hormone receptors As this tumor is almost exclusively found in adolescent boys, there has always been much speculation & indirect evidence that sex hormone receptors play some part in its development. Recent immunocytochemical techniques have been used to show that androgen receptors are present in at least 75% of tumors, these receptors being present in both the vascular & stromal elements. A small proportion of tumors also have some progesterone receptors . In contrast, oestrogen receptors have not been demonstrated.

14. 2. A ngiogenic growth factor Vascular endothelial growth factor has been found localized on both endothelial and stromal cells perhaps indicating that both cell types play a role in tumour development, It has no role with aggressiveness. 3. Insulin like growth factor II (IGFII) Overexpression of IGFII has also been found in a large no. of cases.(short arm of ch.11). Over-expression of IGFII might associated with a tendency to recurrence & poorer prognosis.

15. 4. Familial adenomatous polyposis JNA 25 times more common with FAP. Mutations of the adenomatous polyposis coli (APC)gene(ch.5q). APC gene regulates the beta catenin pathway which influences cell to cell adhesion. Mutation of beta catenin have been found in sporadic & recurrent JNA. 5. TGF-beta It helps to regulate the cell cycle and induces angiogenesis.

16. VEGF expressed in almost in every tumor and TGF-b in most of them, indicating the nature of this tumor with an aggressive and angiogenic character. Estrogen and Progesterone receptor expression was low to indicate a relation to angiogenesis and etiology of this disease

17. JUVENILE ANGIOFIBROMA AND FIRST BRANCHIAL ARCH ARTERY It has been proposed that the tumour origin is based on an incomplete regression of the first branchial arch artery. During embryological development, the first branchial arch artery finally recedes close to the pterygoid base and sphenopalatine foramen regions. Vascular remnants of this artery are incorporated into the sphenopalatine and maxillary arteries themselves. Both the proximity of tumour origin &its main blood supply from SPA,MA, can be explained by this theory.

18. Persistent vascular remnants of the first branchial arch artery contacting the ICA are able to account for the observation of a vascular supply from the ICA. This theory also elucidates the common finding of residual tumour at the pterygoid base and clivus and explains why it is necessary to drill the bone in this specific location in order to remove tumour remnants at the site of origin.

19. Pathology

20. Macroscopic- Grossly the tumor appears as a rounded, nodular, reddish, non capsulated, polypoidal , mass that are covered by nasopharyngeal mucosa. Their growth pattern are both expansile & infiltrative which accounts for their aggressive local behavior. Microscopic The tumour consists of proliferating, irregular vascular channels within a fibrous stroma . Vascular component more in young,as age increses,collagen content increses .

21. Tumour blood vessels typically lack smooth muscle and elastic fibres in tunica media, this is the reason for sustained bleeding. The characteristic absence of an inflammatory infiltrate in the angiofibroma helps to further distinguish it from the more common nasal polyp. (A) Irregular, delicate, thin-walled blood vessels are dispersed in a hypocellular fibrous stroma (B) The spindle cells display occasional cytoplasmic extensions and are embedded in a collagenized background.

22. Pathophysiology

23. The proposed origin of JNA is located along postero -lateral wall in the roof of nasopharynx , usually in the region of the superior margin of the sphenopalatine foramen(which is formed by the junction of the trifurcation of palatine bone, horizontal wing of vomer , and the roof of pterygoid plates). Rather than invading surrounding tissue, this tumour displaces and distorts, relying on pressure necrosis to destroy and push through its bony confines. Intracranial extension is noted in 10-20% of cases.

24. Extension

25. Sphenopalatine foramen * Pterygomaxillary fossa * Infratemporal fossa and *Inferior orbital fissure *Nasal cavity * Nasopharynx *Soft palate *Posterior wall of maxillary sinus, cheek *Extends in the sphenoid sinus & sella turcica , cavernous sinus may be involved. *Through pterygoid process may involve middle cranial fossa *Lateral and posterior walls of sphenoid sinus can be eroded.

26. It follows the lines of least resistance – It mostly arises from SPF area. It may have 2 components – one filling the nasopharynx and the other extending out into the pterygopalatine and infratemporal fossa . Central stalk joining the 2 components occupy the SPF at the upper end of the vertical plate of palatine bone. 1> hangs down in the nasopharynx and may depress the soft palate when large enough

27. 2> may grow into I/L nasal passage towards anterior nares . It can cause pressure on lateral wall and also on septum bending it to opposite side. Corresponding turbinates and ethmoidal air cells and the related antral wall may suffer pressure atrophy. Broadening of the nasal bridge, unilateral cheek prominence and displacement of the Globe of the eye commonly known as  Frog face Deformity due to the forward spread involving the ethmoidal region.

28. Lateral spread into the maxillary sinus may be responsible for the cheek swelling. 3> it can encroach into the orbit through infra orbital fissure and causes exophthalmos . 4> it can erode skull base and cause intracranial problems.

29. From its origin in the pterygo -palatine fossa the tumour usually expands- Medially into the posterior nose and nasopharynx , typically positioned submucosally and causing nasal obstruction. Superiorly into the sphenoid and the orbit. Laterally extend to the pterygomaxillary fissure and cause bowing of the posterior wall of the maxillary sinus. Further, it may involve the infratemporal fossa and middle cranial fossa . Anteriorly into the nasal cavity and sinuses.

30. Intracranial Extension It has been reported to occur in about 20%, almost always extradural , and usually to the middle cranial fossa ( peri -cavernous). 1. Tumour extension via the inferior orbital fissure into the orbit and subsequent posterior extension of orbital tumour via the superior orbital fissure into the middle cranial fossa .( tumour location antero -lateral to cavernous sinus)( most common)

31. 2. Expansion of tumour in the sphenoid sinus with erosion of its lateral wall .( tumour location medial to cavernous sinus) 3. Expansion of tumour into the pterygoid base and the cancellous diploe of the sphenoid bone, and further superior erosion of the greater wing of sphenoid with extension into the middle cranial fossa

32. Clinical Features

33. Sphenopalatine foramen *Extends in the sphenoid sinus & sella turcica , cavernous sinus may be involved. *Through pterygoid process may involve middle cranial fossa *Lateral and posterior walls of sphenoid sinus can be eroded. *Olfactory fossa . * Pterygomaxillary fossa * Infratemporal fossa and *Inferior orbital fissure to orbit *superior orbital fissure *Posterior wall of maxillary sinus, cheek * ANTRAL SIGN *2,3 rd , 4 th , 6 th CN palsy *Lateral rectus palsy * Hyposmia / Anosmia * cavernous sinus thrombosis * Nasal mass, obstruction, recurrent bleeding *Sinusitis, secretory otitis media, CHL * Rhinolalia clausa , dacrocystitis *Nasal cavity * Nasopharynx * Lacrimal duct *Eustachian tube dysfunction * Diplopia * Proptosis “frog face deformity” *Temporal swelling *blindness *Cheek sweeling *

34. Profuse and Recurrent epistaxis .(m/c) Progressive nasal obstruction (starts with unilateral). Mass in nasopharynx .

35. Blockage of ET orifice may cause conductive deafness and otitis media effusion. Chronic anaemia may be present due to repeated epistaxis . Patients may have hyposmia or anosmia .

36. Voice acquires a nasal intonation and may become plummy if swelling enlarges to force the soft palate down. Headache may be present due to chronic sinusitis history or intracranial extension. Pressure on optic chaisma due to erosion of mass into the cranial cavity may cause diplopia . Tenting of the optic nerve by tumour mass may cause failing vision ( as observed by shaheen et al).

37. On Anterior rhinoscopy – Abundant purulent nasal secretions. Accumulations of secretions anterior to mass – CHOANAL BANKING EFFECT. Bowing of nasal septum to uninvolved side. On Posterior rhinoscopy – Pink or red mass filling the nasopharynx can be seen.

38. When disease becomes extensive involving nose and infratemporal fossa , gross physical signs will be seen – Nasal bones become spayed out, Swelling in the temple and cheek occur. Impaction of bulky mass in the infratemporal fossa results in trismus and bulging of the parotid.

39. Blood supply of JNA from the 1. sphenopalatine and maxillary arteries(early) 2. branches of the external carotid artery, such as the ascending pharyngeal artery(advance) 3. Internal carotid arteries (ICAs), the vertebral arteries have to be considered as additional feeders,especially in large JAs

40. Investigations

41. X ray PNS Now-a-days, the diagnosis is based on the CT and MR appearances that are sometimes confirmed by angiography. Biopsy is contra-indicated because of brisk haemorrhage . Routine blood investigations

42. 1>X ray- X-rays of paranasal sinuses may reveal opacity in the nose and sinus areas.  Xray skull lateral view may show the mass inside the nasopharynx . Holman-Miller Sign Characteristic anterior bowing of posterior maxillary wall

43. 2> CT Scan A CT scan is considered most important to show the bony changes because of the complexity of bony structure as the skull base. Lesion enhances with contrast on CT.

44. Coronal CT: Bone Window Widening of left sphenopalatine foramen Lesion fills left choanae Extends into sphenoid sinus

45. Axial CT: Soft Tissue Window with Contrast Homogenous enhancement Widening of left sphenopalatine foramen Extension into Nasopharynx Pterygopalatine fossa

46. HOLMAN MILLER SIGN

47. HONDOUSA SIGN

48. SIGNIFICANCE OF PTERYGOID WEDGE It is defined as the anterior junction of the medial & lateral pterygoid plates. Involvement of pterygoid wedge is found in 99% cases. Pterygoid wedge is the Epicenter of tumour .

49. Most common site of residual & recurrent disease – pterygoid wedge (45%) Most important step in JNA surgery to prevent recurrence - Drilling of pterygoid wedge Average width of the involved side was about 1.8 times greater than that of uninvolved side.

50. RAM HARAN SIGN (named after the authors Dr. Janakiram and Dr. Bavaharan ).

51. CHOP STICK SIGN On postoperative CECT due to drill the cancellous bone in the pterygoid wedge resulted in the appearance of the two pterygoid plates as parallel lines, which resemble CHOPSTICKS.

52. 3> MRI Characteristic – Salt & Pepper appearance due to flow voids It aids in differentiation of tumour in – Orbit , Cavernous sinus , Middle cranial fossa , Infratemporal region. Avoidance of diagnostic radiations in young patients who require serial follow up studies. Serial substraction MRI studies are useful to show the size & extent of residual tumor.

53. Coronal MRI : T1 with Contrast Diffuse intense enhancement Multiple flow voids within hypervascular mass Extension into Nasopharynx Pterygopalatine fossa

54. Axial MRI: T1 Heterogeneous intermediate signal Flow voids represent enlarged vessels Extension into Nasopharynx Masticator space

55. Axial MRI: T2 Heterogeneous intermediate to high signal enhancement Multiple flow voids within hypervascular mass Extension into Nasopharynx Pterygopalatine fossa

56. 4> Angiography In past angiography was considered essential for the diagnosis & for assessment of extension of the tumor, which can be done efficiently by CT & MRI. Angiographic features include marked hypertrophy & increase in no. of arteries without segmental narrowing. Circulation is rapid through the tumor in arteries & a dense homogenous tumour blush seen in capillary phase. Angiography is used now a days primarily for preop embolization .

57. Commonest feeding vessel – Internal Maxillary Artery In large tumours – 1. Ascending Pharyngeal Artery 2. Contralateral ECA branches 3. ICA branches - Ophthalmic, Meningo-hypophyseal , Vidian Artery

58. STAGING

59. Janakiram staging system  Based on tumor extent as seen on preoperative contrast-enhanced CT.

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