Transcript nasopharynx paranasal sinuses and salivary glands ppt

NASOPHARYNX, PNS & SALIVARY
GLANDS
DR. SRINIVAS RAJKUMAR THIRAVIARAJ
Why is this subdivision
necessary?
The primary tumors in each of these areas have
different routes of
• spread
• nodal dissemination
• prognosis
• Cuboidal chamber
• Begins at Posterior Choana
• Continues into Oropharynx via pharyngeal
isthmus
Boundaries:
Anterior:
• posterior nasal cavity
Posterosuperior:
• Lower clivus, upper cervical
• spine, and prevertebral
• muscles
Inferior:
• Divided from the oropharynx
• by a horizontal line drawn
• along the hard and soft
• palates
Neck Lymphatics
• Level I
• below mylohyoid muscle and above the lower
margin of the hyoid bone
• anterior to the posterior border of the
submandibular glands
• level Ia - submental nodes - between the anterior
bellies of the digastric muscles
• level Ib - submandibular nodes - posterolateral to
the anterior belly of the digastric muscles
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Level II
internal jugular (deep cervical) chain
base of skull to inferior border of hyoid bone
anterior to the posterior border of sternocleidomastoid
(SCM) muscle
posterior to the posterior border of the submandibular
glands
level IIa - anterior, lateral, or medial to the vein or posterior
to the internal jugular vein and inseparable from it
level IIb - posterior to the internal jugular vein and have a
fat plane separating the nodes and the vein
between CCAs, below superior aspect of manubrium
• Level III
• internal jugular (deep cervical) chain
• lower margin of hyoid to lower margin of
cricoid cartilage
• anterior to the posterior border of SCM
• lateral to the medial margin of the common
carotid artery (CCA)/internal carotid artery
(ICA)
• Level IV
• internal jugular (deep cervical) chain
• lower margin of cricoid cartilage to level of the
clavicle
• anterior and medial to an oblique line drawn
through the posterior edge of the
sternocleidomastoid muscle and the
posterolateral edge of the anterior scalene
muscle 4
• lateral to the medial margin of the CCA
• Level V
• posterior triangle (spinal accessory) nodes
• level Va - superior half, posterior to levels II
and III (between base of skull and inferior
border of cricoid cartilage)
• level Vb - inferior half, posterior to level IV
(between inferior border of cricoid cartilage
and the level of clavicles)
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Level VI
prelaryngeal/pretracheal/Delphian node
anterior to visceral space
from inferior margin of hyoid bone to
manubrium
• anterior to of levels III and IV
• Level VII
• superior mediastinal nodes
Foramen lacerum
• triangular hole between sphenoid, apex of
petrous temporal and basilar part of occipital.
• The artery of pterygoid canal, the nerve of
pterygoid canal and some venous drainage
pass through the foramen lacerum.
• Foramen Ovale
• Posterior part of the sphenoid bone,
Posterolateral to the foramen rotundum.
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Otic ganglion,
V3( Mandibular nerve )
Accessory meningeal artery,
Lesser petrosal nerve,
Emissary veins)
CA Nasopharynx
• Carcinoma of the nasopharynx frequently
arises from the lateral wall, with a predilection
for the fossa of Rosenmuller
LOCAL SPREAD
• Anteriorly into the nasal fossa,
• Posterolaterally beyond the pharyngobasilar
fascia to involve the parapharyngeal and the
carotid spaces
• Laterally to the pterygoid muscles,
• Posteriorly to the prevertebral muscles
• inferiorly to the oropharynx
• Superiorly, bony erosion of the skull base
involving
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The floor of the sphenoid sinus,
Clivus
Apex of petrous bone
Basal foramina.
• ? Intracranially via foramen lacerum
• High frequency of perineural spread along the
maxillary division (V2) and the mandibular
division (V3) of the trigeminal nerve with
subsequent intracranial extension through the
foramen rotundum and foramen ovale
Adjacent soft tissue
Nasal cavity
87
Parapharyngeal space,
carotid space
68
Pterygoid muscle (medial,
lateral)
48
Oropharyngeal wall, soft
palate
21
Prevertebral muscle
19
Bony erosion/paranasal sinus
Clivus
Sphenoid bone, foramina
lacerum, ovale, rotundum
41
38
Pterygoid plate(s),
pterygomaxillary fissure,
pterygopalatine fossa
27
Petrous bone, petro-occipital
fissure
19
Ethmoid sinus
Maxillary antrum
Jugular foramen, hypoglossal
canal
Pituitary fossa/gland
6
4
4
3
Extensive/intracranial extension
Cavernous sinus
16
Infratemporal fossa
9
Orbit, orbital fissure(s)
4
Cerebrum, meninges,
cisterns
Hypopharynx
4
2
Nasopharynx Imaging
• Before the era of CT - plain radiography
• The classic 5 views of NPC that Ho described
consist of lateral, submentovertical,
occipitosubmental, 25° occipitomental, and
occipitomaxillary views
• T1 Attenuation = Metastasis
PARA NASAL SINUSES
Ethmoid Sinuses
• the Ethmoid air cells
• separated from the orbital cavity by a thin,
porous bone, the lamina papyracea, and from the
anterior cranial fossa by a portion of the frontal
bone, the fovea ethmoidalis.
• They are in close proximity to the optic nerves
laterally and the optic chiasm posteriorly.
• The middle ethmoid cells open directly into
the middle meatus.
• The anterior cells may drain indirectly into the
middle meatus via the infundibulum.
• The posterior cells open directly into the
superior meatus.
• The various radiographic positions used to study paranasal
sinuses are:
• 1. Occipito-mental view (Water's view)
• 2. Occipital-frontal view (Caldwel view)
• 3. Submento-vertical position (Hirtz position)
• 4. Lateral view
• 5. Oblique view 39 Degrees oblique (Rhese position)
Maxillary Sinuses
• The maxillary sinuses are the largest of the
paranasal sinuses.
• They are pyramid-shaped cavities located in
the maxillae.
• The lateral walls of the nasal cavity form the
base and the roofs correspond to the orbital
floors, which contain the infraorbital canals.
• The floors of the maxillary sinuses are
composed of the alveolar processes.
• The apices extend toward and frequently into
the zygomatic bones.
• Secretions drain by mucociliary action into the
middle meatus via the hiatus semilunaris through
an aperture near the roof of the maxillary sinus.
• Ohngren's line is a theoretic plane dividing each
maxillary sinus into the suprastructure and
infrastructure; it is defined by connecting the
medial canthus with the angle of the mandible.
Sphenoid Sinus
• The sphenoid bone forms a midline inner
cavity that communicates with the nasal cavity
through an aperture in its anterior wall
• It is directly apposed superiorly to the
pituitary gland and optic chiasm, laterally to
the cavernous sinuses, anteriorly to the
ethmoid sinuses and nasal cavity, and
inferiorly to the nasopharynx.
FRONTAL SINUS
• The paired, typically asymmetric frontal
sinuses are located between the inner and
outer tables of the frontal bone.
• They are anterior to the anterior cranial fossa,
superior to the sphenoid and ethmoid sinuses,
and superomedial to the orbits. They usually
communicate with the middle meatus of the
nasal cavity.
NATURAL HISTORY
• Nasal vestibule carcinomas can spread by direct
invasion of the upper lip, gingivolabial sulcus,
premaxilla (early events), or nasal cavity (late event)
• Vertical invasion may result in septal (membranous or
cartilaginous) perforation or alar cartilage destruction.
• Lymphatic spread from nasal vestibule carcinomas is
usually to the ipsilateral facial (buccinator and
mandibular) and submandibular nodes.
Nasal Cavity and Ethmoid Sinuses
Ca Spread
• The pattern of contiguous spread of carcinomas
varies with the location of the primary lesion.
• Tumors arising in the upper nasal cavity and
ethmoid cells can extend to the orbit through the
thin lamina papyracea and to the anterior cranial
fossa via the cribriform plate, or they may grow
through the nasal bone to the subcutaneous
tissue and skin.
• Lateral wall primaries invade the maxillary
antrum, ethmoid cells, orbit, pterygopalatine
fossa, and nasopharynx.
• Primaries of the floor and lower septum may
invade the palate and maxillary antrum.
• Perineural extension (typically involving
branches of the trigeminal nerve) is seen most
frequently with adenoid cystic carcinomas.
• Lymphatic spread of nasal cavity primaries is
uncommon, although spread to
retropharyngeal and cervical lymph nodes is
possible
Maxillary Sinuses
• The pattern of spread of maxillary sinus
cancers varies with the site of origin.
• Suprastructure tumors extend into the nasal
cavity, ethmoid cells, orbit, pterygopalatine
fossa, infratemporal fossa, and base of skull.
• Invasion of these structures gives lesions of
the suprastructure a poorer prognosis.
• Treatment is associated with greater
morbidity as a consequence of craniofacial
resection or radiation of intracranial and
ocular structures
• . Infrastructure tumors often infiltrate the
palate, alveolar process, gingivobuccal sulcus,
soft tissue of the cheek, nasal cavity, masseter
muscle, pterygopalatine space, and pterygoid
fossa.
• The maxillary sinuses are have a limited
lymphatic supply
• Correspondingly low incidence of
lymphadenopathy at diagnosis (Ipsilateral
subdigastric and submandibular nodes are
involved most frequently.
• Hematogenous spread is uncommon.
CLINICAL PRESENTATION
Nasal Vestibule
• Asymptomatic plaques or nodules, often with
crusting and scabbing.
• Advanced lesions - pain, bleeding, or
ulceration.
Nasal Cavity
• Nasal cavity tumors present with symptoms and signs
of nasal polyps (e.g., chronic unilateral discharge, ulcer,
obstruction, anterior headache, and intermittent
epistaxis), hence delaying the diagnosis.
• Additional symptoms and signs develop as the lesion
enlarges: medial orbital mass, proptosis, expansion of
the nasal bridge, diplopia resulting from invasion of the
orbit, epiphora due to obstruction of the nasolacrimal
duct, anomaly of smell or anosmia from involvement of
the olfactory region, or frontal headache due to
extension through the cribriform plate.
Ethmoid Sinuses
• Central/facial head-aches and referred pain to
the nasal or retrobulbar region,
• a subcutaneous mass at the inner canthus,
• nasal obstruction and discharge,
• diplopia, and proptosis.
Maxillary Sinuses
• Diagnsosis mostly made in advanced stages
• facial swelling, pain, or
• paresthesia of the cheek induced by disease
extension to the premaxillary region,
• epistaxis, nasal discharge and obstruction related
to tumor spread to the nasal cavity
SALIVARY GLANDS
Parotid Gland
• The gland has four surfaces superficial or
lateral,superior, anteromedial and
posteromedial.
• The gland has three borders anterior, medial
and posterior. The Parotid gland has two ends:
superior end in the form of small superior
surface and an inferior end (apex).
• (1) Superficial or lateral relations: The gland is
related superficially to the skin. Superficial
fascia, superficial lamina of investing layer of
deep cervical fascia and Great auricular nerve
(anterior ramus of C2 and C3)
• (2) Anteromedial relations: The gland is
related anteromedially to the mandibular
ramus, masseter and medial pterygoid
muscles. A part of the gland may extend
between the ramus and medial pterygoid as
the pterygoid process. Branches of facial nerve
and parotid duct emerge through this surface.
• (3) Posteromedial relations: The gland is related
posteromedially to mastoid process of temporal
bone with its attached Sternocleidomastoid and
digastric muscles, styloid process of temporal
bone with its three attached muscles (Stylohyoid,
Stylopharyngeus and Styloglossus) and carotid
sheath with its contained neurovasculature
(Internal Carotid artery, Internal Jugular vein, 9th,
10th, 11th and 12th cranial nerves)
• .
• (4) Medial relations: The parotid gland comes
into contact with the superior pharyngyeal
constrictor muscle at the medial border where
the anteromedial and posteromedial surfaces
meet. Hence there is a need to examine the
fauces in parotitis
Parotid Gland Anatomy Summary
• Superficial to and partly behind the ramus of
the mandible and covers the masseter muscle.
• Superficially, it overlaps the posterior part of
the muscle and largely fills the space between
the ramus of the mandible and the anterior
border of the sternocleidomastoid muscle.
• One or more isthmi that wrap around the
branches of the facial nerve connect the
superficial and deep lobes of the gland.
• The nerve enters the deep surface of the
gland as a single trunk, passing posterolateral
to the styloid process.
• It usually leaves the gland as five or more
branches, emerging at the anterior, upper, and
lower borders of the gland.
• The facial nerve runs superficial to the main
blood vessels that traverse the gland but is
interwoven within the glandular tissue and its
ducts.
• The parotid gland contains an extensive
lymphatic capillary plexus, many aggregates of
lymphocytic cells, and numerous
intraglandular lymph nodes in the superficial
lobe
• Lymphatics drain from more lateral areas on
the face, including parts of the eyelids,
diagonally downward and posteriorly toward
the parotid gland, as do the lymphatics from
the frontal region of the scalp.
• Superficially and more deeply, are parotid nodes.
• Drain downward along the retromandibular vein to
empty in part into the superficial lymphatics and nodes
along the outer surface of the sternocleidomastoid
muscle and in part into upper nodes of the deep
cervical chain.
• Lymphatics from the parietal region of the scalp drain
partly to the parotid nodes in front of the ear and
partly to the retroauricular nodes in back of the ear,
which, in turn, drain into upper deep cervical nodes
Innervation
• Entirely autonomic.
• Postganglionic sympathetic fibers from superior
cervical sympathetic ganglion reach the gland as
periarterial nerve plexuses around the external
carotid artery and their function is mainly
vasoconstriction.
• The cell bodies of the preganglionic sympathetics
usually lie in the lateral horns of upper thoracic
spinal segments.
• Preganglionic parasympathetic fibers leave the brain
stem from inferior salivatory nucleus in the
glossopharyngeal nerve (cranial nerve IX) and then
through its tympanic and then the lesser petrosal
branch pass into the otic ganglion. There, they synapse
with postganglionic fibers which reach the gland by
hitch-hiking via the auriculotemporal nerve, a branch
of the mandibular nerve.
• Parotid gland salivation is ultimately caused by the
glossopharyngeal nerve
Submandibular Gland
• The paired submandibular glands or
submaxillary glands are major salivary glands
located beneath the floor of the mouth.
• They weigh about 15 grams and produce
around 60-67% of the total volume of saliva.
• Fills the triangle between the two bellies of the
digastric and the lower border of the mandible
and extends upward deep to the mandible.
• It lies partly on the lower surface of the
mylohyoid and partly behind the muscle against
the lateral surface of the muscle of the tongue,
the hypoglossus.
• The submandibular gland has a larger superficial
part, or body, and a smaller deep process.
• The inferior surface is adjacent to the
submandibular lymph nodes, and the deep
process of the submandibular gland lies
between the mylohyoid laterally and the
hyoglossus medially, and between the lingual
nerve above and the hypoglossal nerve below
.
• Rich lymphatic capillary network lies in the
interstitial spaces of the gland.
• From the lateral and superior portions of the
gland, lymph flows to the prevascular or
preglandular submandibular lymph nodes.
• The posterior portion of the gland gives rise to
one or two lymphatic trunks, which follow the
facial artery and go directly to the anterior
subdigastric nodes of the internal jugular
chain .
• Arterial Supply - facial and lingual arteries.
• Venous Drainage - lingual and facial veins.
• Lymphatics - The submandibular nodes lie in
close proximity to the gland, or within its
structure. Lymph flows from this region to the
upper deep cervical nodes (level II).
Lymphatic Spread
• Lymph will usually travel to upper deep
cervical nodes, including the jugulo-omohyoid
node.
Innervation
• The submandibular ganglion is the source of
neural supply to the submandibular gland. This
small ganglion is associated with the lingual nerve
as it passes anteriorly along the floor the mouth.
Parasympathetic fibres arrive via the chorda
tympani, a branch of the facial nerve VII.
Sympathetic fibres are derived from the facial
artery plexus.
• General sensory nerves arrive from the lingual
nerve (V3).
Sublingual Gland
• This smallest of the three major salivary
glands
• Lies between the mucous membrane of the
floor of the mouth above and the mylohyoid
muscle below, the mandible laterally, and the
genioglossus muscles of the tongue medially .
• The sublingual gland drains either to the
submandibular lymph nodes or more
posteriorly into the deep internal jugular chain
between the digastric and omohyoid muscles.
Rarely, the lymphatics of the sublingual gland
drain into a submental node or
supraomohyoid jugular node
• Arterial Supply
• The sublingual branch of the lingual artery and submental branch of
the facial artery contribute to the supply of the sublingual gland.
• Venous Drainage
• Either accompanying sublingual veins to the common facial vein or
passing laterally to the facial vein.
• Lymphatics
• The sublingual gland drains primarily to submental nodes.
Innervation
• via the submandibular
ganglion,
• Nerves passing to the
sublingual gland leave the
ganglion and region the
lingual nerve, before
departing again to supply
their target organ
• Sub lingual , Y-Mylohyoid, T - Hyoglossus
NATURAL HISTORY
• Local invasion is the initial route of spread of
malignant tumors of the salivary glands,
depending on location and histologic type. For
parotid tumors, this may result in fixation to
structures in around 20% of cases . Skin
invasion is more often seen in parotid tumors
(10%), compared with submandibular tumors
(3%) .
• Approximately 25% of patients with a
malignant parotid salivary gland tumor
present with facial palsy from cranial nerve
invasion
Clinical Presentation
• Three of four parotid masses are benign .
• Patients most often have a painless, rapidly
enlarging mass, often present for years before
a sudden change in its indolent growth
pattern prompts the patient to seek medical
attention
Duration of clinical symptoms before diagnosis
may last more than 10 years . For malignant
tumors, the median duration of clinical
symptoms generally is shorter (3 to 6 months)
compared to that of benign tumors, although for
some minor salivary gland tumors, median
periods of 2 year have been reported .
• Pain is more frequently associated with
malignant disease.
• Although as many as one third of parotid
cancers may have facial nerve involvement,
only 10% to 20% of patients complain of pain .
• Pain may appear with involvement of deeper
structures (masseter, temporal, and pterygoid
muscles).
Rarely, tumors of the parotid may involve the
base of skull and cause intractable pain and
paralysis of various cranial nerves.