European Course in Head and Neck Neuroradiology Disclosures 1st Cycle – Module 2 25th to 27th March 2021 No conflict of interest regarding this presentation. Oropharynx and Pathologies

Teresa Nunes Hospital Garcia de Orta, Hospital Beatriz Ângelo Portugal

Oropharynx: Anatomy and Pathologies Oropharynx: Anatomy

Objectives Nasopharynx • Review the anatomy of the oropharynx (subsites, borders, surrounding spaces) Oropharynx • Become familiar with patterns of spread of oropharyngeal infections and tumors Hypopharynx

• Highlight relevant imaging findings for accurate staging and treatment planning of oropharyngeal squamous cell carcinoma

Oropharynx: Surrounding Spaces Oropharynx: Borders

Anteriorly Oral cavity Superior Soft Laterally Anterior Circumvallate papillae Masticator space Anterior tonsillar pillars Posteriorly Posterior Posterior pharyngeal wall Lateral Anterior tonsillar pillars Posterior tonsillar pillars Inferior Vallecula Oropharynx: Borders Oropharynx: Borders

Oropharyngeal isthmus

Superior Anterior Circumvallate papillae Anterior 2/3 vs posterior 1/3 of Anterior tonsillar pillars Inferior Vallecula Anterior tonsillar pillar: most common Pre-epiglottic space Glossopiglottic fold (median) location of oropharyngeal squamous Can not be assessed clinically Pharyngoepiglottic folds (lateral) Invasion requires supraglottic laryngectomy !cell carcinoma !

Oropharynx: Borders Muscles of the Pharyngeal Wall

Posterior pharyngeal wall Fascial layers Pharyngeal constrictor muscles as barriers to spread of disease !

• Pharyngeal constrictor muscles Superior, Middle, Inferior • Paired muscles Stylopharyngeus, Palatopharyngeus, Salpingopharyngeus

Kamalian S, Avery L, Lev MH, Schaefer PW, Curtin HD, Kamalian S. Nontraumatic Head and Neck Emergencies. Radiographics. 2019 Oct;39(6):1808-1823. doi: 10.1148/rg.2019190159.

Pterygomandibular Raphe Oropharynx: 4 Subsites

Posterior Base of tongue Soft palate pharyngeal wall

• From hammulus of medial pterygoid plate to mylohyoid ridge of • Attachment of buccinator and superior pharyngeal constrictor muscle

Subjacent to retromolar trigone Route of lesion of spread ! (Alveolar ridge, buccal mucosa, masticator space, mandible, superior constrictor muscle) Oropharynx: Soft Palate Oropharynx: Tonsil

• Tonsillar pillars • Tensor veli palatine • Anterior: palatoglossus • Levator veli palatine • Soft palate J Base of tongue • Palatopharyngeus • Glossotonsillary sulcus J Base of tongue • Palatoglossus • Posterior: palatopharyngeus • Musculus uvulae • (aka Faucial tonsil) • Encapsulated lymphoid tissue • Deep crypts as reservoir for HPV

• Peritonsillar space • Potential space between tonsillar capsule and superior pharyngeal muscle

Oropharynx: Base of Tongue Waldeyer’s Ring

Ring of lymphoid tissue in the naso-oropharynx • WŽƐƚĞƌŝŽƌЫŽĨƚŚĞƚŽŶŐƵĞ • Posterior to circumvallate

papillae Tubal tonsil • Lingual tonsil

Palatine Palatine • Variable in size tonsil tonsil • Age, compensatory hypertrophy after palatine • ĞŶƐĞƚŽŶŐƵĞŵƵƐĐƵůĂƚƵƌĞї^ŵĂůůƚƵŵŽƌƐŽĨƚĞŶĚŝĨĨŝĐƵůƚƚŽĚĞƚĞĐƚŽŶŝŵĂŐŝŶŐ͊ Lingual tonsil

Fricke BL, Donnelly LF, Shott SR, Kalra M, Poe SA, Chini BA, Amin RS. Comparison of lingual tonsil size as depicted on MR imaging between children with obstructive despite previous tonsillectomy and adenoidectomy and normal controls. Pediatr Radiol. 2006 Jun;36(6):518-23. doi: 10.1007/s00247-006-0149-7. Epub 2006 Apr 5.

Extrinsic Tongue Muscles Oropharynx: TransOral Robotic Surgery

• Genioglossus muscle • Hyoglossus muscle • Styloglosus muscle • Palatoglossus muscle Oropharynx: Infections Airway Oropharynx: Infections Mediastinum Cervical vessels • Differentiate cellulitis from abscess Peritonsillar abscess J Parapharyngeal space spread (anterior compartment) ! Suppurative retropharyngeal adenitis J Parapharyngeal space spread • Cellulitis: Fat planes obliteration without contrast enhancement (post-styloid compartment) • Abscess: Rim enhancement around a non-enhancing core

• Assess the pattern of spread • Single non vertical fascial space • >2 non vertical fascial spaces • Along vertically oriented spaces (parapharyngeal, retropharyngeal, paravertebral)

“Kissing ”

Maroldi R, Farina D, Ravanelli M, Lombardi D, Nicolai P. Emergency imaging assessment of deep neck space infections. Semin Ultrasound CT MR. 2012 Oct;33(5):432- Maroldi R, Farina D, Ravanelli M, Lombardi D, Nicolai P. Emergency imaging assessment of deep neck space infections. Semin Ultrasound CT MR. 2012 Oct;33(5):432- 42. doi: 10.1053/j.sult.2012.06.008. 42. doi: 10.1053/j.sult.2012.06.008.

Oropharynx: Infections Oropharynx: Infections

Airway Retropharyngeal Suppurative Retropharyngeal edema retropharyngeal node abscess Mediastinum Fluid distribution From side to side Unilateral From side to side Cervical vessels Configuration Rounded, “bow tie” Rounded or ovoid Rounded or ovoid ! Retropharyngeal or rectangular edema Retropharyngeal edema Mass effect Mild Moderate/marked Primary infection Enhancing wall No May be present Present (otitis media, tonsillitis…) Int. jugular vein thrombosis Lemierre’s syndrome: Infectious thrombophlebitis Ca2+ anterior C1-C2

Calcific longus colli Hoang JK, Branstetter BF 4th, Eastwood JD, Glastonbury CM. Multiplanar CT and MRI of collections in the retropharyngeal space: is it an abscess? AJR Am J Roentgenol. 2011 Radiotherapy . Apr;196(4):W426-32. doi: 10.2214/AJR.10.5116. PMID: 21427307. tendinitis

Oropharynx: Neoplasms Oropharynx: Tumor Spread Patterns

• Most malignant tumors of the oropharynx are squamous cell carcinomas (SCC) • Local tumor extension occurs in a predictable pattern • HPV positive SCC are now 70% of all oropharyngeal SCC • Tumors with multiple subsite involvement have worse response to therapy

• 60% HPV positive SCC may present with asymptomatic nodal mass with very small primary (“unknown primary”)

• Lymphoma and non-squamous cell tumors of minor salivary glands can occur

• Accurate anatomic extent of disease is central to staging and prognosis and optimal treatment planning Oropharynx: Tumor Spread Patterns Oropharynx: Tumor Spread Patterns

Palatine tonsils or tonsillar pillars Palatine tonsils or tonsillar pillars

Superior Soft and (palatoglossus muscle) Nasopharynx and skull base (tensor and levator veli palatini, pterygoid muscles) Anterior Pterygomandibular raphe, retromolar trigone, oral cavity, (superior constrictor muscle) Inferior Base of tongue (palatoglossus muscle) Posterior Retropharyngeal or carotid space

Oropharynx: Tumor Spread Patterns Oropharynx: Tumor Spread Patterns

Palatine tonsils or tonsillar pillars Base of tongue Medial Crosses midline? Lateral Pharyngeal mucosa, mandible (pterygomandibular raphe) Anterior Oral tongue, floor of and Inferior Vallecula, laryngeal pre-epiglottic fat Posterior Parapharyngeal space, carotid sheath

Oropharynx: Tumor Spread Patterns Oropharynx: Lymphatic Drainage System

Base of tongue • Primarily level II and III • Retropharyngeal nodes • Soft palate • Posterior pharyngeal wall SCC

• Contralateral nodes • Higher in HPV positive SCC

• Bilateral nodes • Base of tongue • Posterior pharyngeal wall SCC Oropharynx SCC: Two Distinct Cancers… Oropharynx: SCC - Squamous Cell Carcinoma

HPV positive HPV negative AJCC Staging Manual – 8th Edition Age Younger Older Risk factors Sexual behaviour Alcohol, tobacco Incidence Increasing Decreasing Anatomic site Tonsil, base of tongue All sites Borders Well defined Poorly defined Nodes Multiple nodes Fewer nodes Lower ADC (<1 x 10-3 mm2/sec) (Pseudo)-cystic degeneration 5 year survival 90% 40%

Parvathaneni U, Lavertu P, Gibson MK, Glastonbury CM. Advances in Diagnosis and Multidisciplinary Management of Oropharyngeal Squamous Cell Carcinoma: State of the Art. Radiographics. 2019 Nov-Dec;39(7):2055-2068. doi: 10.1148/rg.2019190007. Epub 2019 Oct 11.

Oropharynx: SCC - Squamous Cell Carcinoma Oropharynx: SCC Staging

AJCC Staging MManualannuaual – 8 th EditionEdittioon size + signs advanced disease + nodes • Extrinsic muscles of tongue • Larynx* • Masticator space muscles • Jaw • Skull base • Encasement of internal carotid • Nodes: size, level, ipsi, contra or bilateral, ENE

Mucosa extension to lingual surface of epiglottis from base of tongue and vallecular tumors does not constitute invasion of the larynx Parvathaneni U, Lavertu P, Gibson MK,MK, Glastonbury CM. Advances in DiagnosisDiagnosis andanndMudMulddMult MultidisciplinaryMultMuMlMultullttiidiscidisididisciddiscidiscdisiisisciiscssciscciciplinarplinappl narnnaaary ManagementMManagement of OropharyngealOrop Squamous Cell Carcinoma: State of the Art.Art. Radiographics.Radiographics. 20192019 Nov-Dec;39(7):2055-2068.Nov-Dec;39(7):2055-2068.8 doi:ddoidooioi::1:10 10.1 10.10.1148/rg.2019190007.0100.11148/11414848/4488/rg8/8/ .2019190007. EpuEpubb 2019 Oct 11. !

Oropharynx: SCC Staging Oropharynx: Lymphoma

Extranodal extension Nodal disease • Hodgkin Lymphoma: 98% nodal disease • Non-Hodgkin Lymphoma: 30% extra-nodal • Tumor extension through the fibrous capsule of a Extranodal disease • Multiple, bilateral, non-necrotic enlarged nodes • Involvement of skin, adjacent musculature, neural structures • Lymphatic: Waldeyer’s ring • Radiologic evidence alone may be supportive but is not sufficient independently • Extralymphatic: • Orbit Radiologic ENE • Sinonasal • Indistinct nodal margins • Salivary glands • Irregular capsular enhancement • Thyroid • Surrounding fat or muscles infiltration • Bone

Weber AL, Rahemtullah A, Ferry JA. Hodgkin and non-Hodgkin lymphoma of the head and neck: clinical, pathologic, and imaging evaluation. Neuroimaging Clin N Am. 2003 Aug;13(3):371-92. doi: 10.1016/s1052-5149(03)00039-x. PMID: 14631680. Oropharynx Oropharynx: Anatomy and Pathologies

• The oropharynx comprises 4 subsites (base of tongue, palatine tonsils, soft palate Submucosal lumps and oropharyngeal wall displacement… and posterior pharyngeal wall)

• Knowledge of the anatomy of the oropharynx, fascial layers and surrounding neck DISH Madelung disease Paraganglioma Goiter spaces is essential to understand the spread patterns of oropharyngeal infections and neoplasms

• Most malignant tumors of the oropharynx are squamous cell carcinomas, which are currently classified according to HPV status

• Precise oropharyngeal tumor staging needed for treatment planning requires assessment of lesion size, extension to surrounding spaces, bone involvement, internal carotid artery encasement and nodal disease

DISH: Diffuse idiopathic skeletal hyperostosis; Madelung disease: multiple symmetric lipomatosis

European Course in Head and Neck Neuroradiology 1st Cycle – Module 2 25th to 27th March 2021 Oropharynx Anatomy and Pathologies

Teresa Nunes Hospital Garcia de Orta, Hospital Beatriz Ângelo Portugal