Head and neck imaging Flashcards
modality of chouce when looking for obstructing salivary ductal calculi or for detection of fractures
CT
Lesions found on PET scan are characterized by a ____ which refers to the relative radioactivity of a particular lesions when standardized to the injection dose and adjusted for body weight
standardized uptake value (SUV)
an SUV of greater than 3 is
pathologic
nonmalignant conditions that may give rise to an elevated SUV
infection and postoperative changes
most common pathology involving the paranasal sinuses and nasal cavity
inflammatory disease
characterized by the presence of air-fluid levels or foamy-appearing sinus secretions and is typically caused by a viral upper respiratory tract infection
acute sinusitis
in this type of sinusitis, changes include mucoperiosteal thickening, as well as osseous thickening of the sinus walls
chronic sinusitis
sphenoid sinusitis is of great clinical concern as it may easily extend in a retrograde fashion intracranially due to
presence of valveless veins
characterized by enlargement of cavernous sinuses, with bowing/convex outer mrgins
cavernous sinus thrombosis
differential diagnostic conditions for the enlargement of the cavernous sinus would include
carotid-cavernous fistula and tolosa-hunt syndrome
used for the evaluation and tx of inflammatory sinonasal disease
endoscopic sinonasal sx
major area of mucociliary drainage
middle meatus, known as the ostiomeatal unit
obstruction to this region will result in isolated obstruction of maxillary sinus
disease limited to the infundibulum
lesion located in this area will lead to combined obstruction of the ipsilateral maxillary sinus, anterior and middle ethmoid air cells and frontal sinus
hiatus semilunaris
common complications associated with sinusitis
inflammatory polyps, mucuous retention cysts, mucoceles and cavernous sinus thrombosis
chronic inflammation leads to mucosal hyperplasia which results in mucosal redundancy and _____
polyp formation
when an antral polyp expands to the point where it prolapses through the sinus ostium, it is referred to as ____. their characteristic appearance is that of a soft tissue mass extending from the maxillary sinus to fill the ipsilateral nasal cavity and nasopharynx
antrochoanal polyp
represent obstructed mucous glands within the mucosal lining. these lesions have a characteristic rounded appearance, measuring one to several centimeters in diameter, with the maxillary sinus being most commonly involved
mucous retention cysts
results from chronic obstruction of a paranasal sinus that becomes blocked and converted into a fluid-filled cyst. over time, the lesion may expand, eroding bone and resulting in proptosis
sinus mucocele
most commonly affected paranasal sinus in mucocele
frontal sinus
if the mucocele becomes infected, it demonstrates peripheral enhancement and is referred to as a
mucopyelocele
named based in their histologic appearance. in this condition, the neoplastic nasal epithelium inverts and grows into the underlying mucosa. they are not believed to be associated with allergy or chronic infection because they are almost invariably unilateral in location
inverted papilloma
inverted papillomas occur exclusively in the
lateral nasal wall, centered on the hiatus semilunaris
tx for inverted papilloma
sx, because of their increased association with squamous cell carcinoma
typically seen in male adolescents presenting with epistaxis. tumor arises from fibrovascular stroma of the nasal wall adjacent to the sphenopalatine foramen. benign tumor that can be very locally aggressive
Juvenile nasopharyngeal angiofibroma
hallmark feature of Juvenile nasopharyngeal angiofibroma
retromaxillary pterygopalatine fossa location
this tumor characteristically fills the nasopharynx and bows the posterior wall of maxillary sinus forward. it enhances markedly with contrast administration, differentiating from the rarer lymphangioma
Juvenile nasopharyngeal angiofibroma
tx for Juvenile nasopharyngeal angiofibroma
embolization, to make them less vascular and facilitate surgical resection
tissues within the paranasal sinuses and nasal cavity that give rise to malignancies include
squamous epithelium, lymphoid tissue and minor salivary glands
most common malignancy of the aerodigestive tract
squamous cell ca
true or false: squamous cell carcinoma of the sinuses is often clinically silent until it is quite advanced. early symptoms are related to obstructive sinusitis
true
minor salivary glands are dispersed throughout the upper aerodigestive tract but are most highly concentrated in the
palate
most of the parotid gland salivary neoplasms are benign or malignant
benign
most of the minor salivary gland neoplasms are benign or malignant
malignant
most common salivary gland malignancies include
adenoid cystic carcinoma, adenocarcinoma and mucoepidermoid carcinoma
tumor that arises from the neurosensory receptor cells of the olfactory nerve and mucosa. thus, this lesion may originate anywhere from the cribriform plate to the turbinates. it is quite destructive by the time of diagnosis and is found high within the nasal vault
esthesioneuroblastoma
in assessing the size and extent of sinonasal cavity pathology, it is often difficult to differentiate the offending lesion from associated obstructed sinus secretions. in such instances, this MR sequence is of value, because in general, sinus secretions will be brighter than the malignancy, which is often isointense with respect to muscle
fat sat T2
skull base extends from the ____ anteriorly, to the _____ posteriorly, and is composed of five bones, namely
extends from the nose anteriorly to the occipital protuberance postererioly and is composed of ethmoid, sphenoid, occipital, temporal and frontal bones
most malignant lesions of the skull base are ____ in origin
metastatic
3 most common primary malignant tumors in the skull base are
chordoma, chondrosarcoma and osteogenic sarcoma
bone neoplasm that arises from remnants of the primitive notochord. classically, this lesion will present as a destructive midline mass centered in the clivus.
chordoma
chordoma may be found anywhere along the craniospinal axis, which include
35% clivus, 50% sacrum, 15% vertebral bodies
this lesion is characterized as a midline destructive bony lesion with predilection for the sphenoocipital synchondrosis
chordoma
occasionally seen as a horizontal line in the midclivus, midway between sella and basion (tip of clivus)
sphenoocipital synchondrosis
malignant tumors that develop from cartilage. because skull base is preformed in cartilage, this tumor has predilection to involve the skull base
chondrosarcoma
preferred site of origin of chondrosarcoma is
parasellar in location, at the petroclival junction
this neoplasm is typically a result of prior radiation therapy or malignant transformation of Paget disease
Osteogenic sarcoma
characteristic for chordoma
central destructive clival lesion
characteristic for chondrosarcoma
paraclival destructive bony lesion
other differential diagnosis aside from chordoma and chondrosarcoma for skull base lesions include
metastatases, myeloma, plasmacytoma, fibrous dysplasia and Paget disease
lesions of the jugular foramen are most commonly
paragangliomas
this arise from glomus cells derived from the embryonic neural crest, functioning as part of the sympathetic nervous system
paragangliomas
paraganglioma in the jugular foramen is called ___. these patients commonly present with pulsatile tinnitus and a conductive hearing loss. CT often demonstrates moth-eaten destruction of the bone surrounding the jugular fossa with MR revealing the typical heterogenous “salt and pepper” signal related to numerous flow voids
glomus jugulare
other lesions of the jugular fossa aside from glomus jugulare include ____ and _____. these lesions cause a smooth expansion of the jugular foramen with marked enhancement
schwannomas and meningiomas
schwannomas in the jugular fossa affects what CNs
IX to XI
most diseases involving the temporal bone are
inflammatory in nature and include cholesteatomas
believed to be the principal defect responsible for inflammatory disease of the middle ear and mastoid
eustachian tube dysfunction with resultant decreased intratympanic pressure
an epidermoid cyst composed of desquamating stratified squamous epithelium these cysts enlarge because of the progressive accumulation of epithelial debris within their lumen
cholesteatoma
congenital cholesteatomas originate from the
stratified squamous epithelium of the tympanic membrane
diagnosis of cholesteatoma is based on the
detection of a soft tissue mass within the middle ear cavity, typically with associated bony erosion
most common site for formation of an acquired cholesteatoma. cholesteatoma arising in this area originate within the Prussak space (superior recess of the tympanic membrane)
superior portion of the tympanic membrane (pars flaccida)
space located medial to the pars flaccida between the scutum and neck of maleus
Prussak space
subtle erosion of scutum and medial displacement of the ossicles can be seen in
cholesteatoma
also known as the giant cholesterol cyst, is a type of granulation tissue that may involve the petrous apex. these lesions represent petrous apex air cells that have become partially obstructed and are filled with cholesterol debris and hemorrhagic fluid. because of their hemorrhagic components, these lesions are characterized by high signal on both T1 and T2
cholesterol granuloma
differential diagnosis for cholesterol granuloma with corresponding MR findings
retained fluid secretions (dark T1, bright T2, nonenhancing), petrous apicitis (dark T1, bright T2 with ring enhancement), nonaerated petrous apex (bright T2, dark T2 and non enhancement)
suprahyoid malignancy in pedia
lymphoma or rhabdomyosarcoma
vast majority of suprahyoid neck mass in pedia are benign or malignant
benign
90% of suprahyoid neck mass in adults are benign or malignant
malignant
in younger adults (20 to 40), most common suprahyoid malignancy is
lymphoma
in adults over 40, most common neck mass will be
nodal metastasis
suprahyoid head and neck is traditionally divided into compartments that include
nasopharynx, oropharynx and oral cavity
lies above the oropharynx and is divided from the oropharynx by a horizontal line drawn along the hard and soft palates. posteriorly it is bounded by the pharyngfeal constrictor muscles and anteriorly it is bounded by the nasal cavity at the nasal choana
nasopharynx
these are paired funnel-shaped opening between the nasal cavity and nasopharynx
nasal choana
oral cavity and oropharynx are divided by a ring of structures that include
circumvallate papillae, tonsillar pillars and soft palate
deep anatomy of the head and neck is subdivided by layers of the deep cervical fascia into the following spaces, namely
superficial mucosal, parapahryngeal, carotid, parotid, masticator, retropharyngeal and prevertebral
contents of the mucosal space
squamous mucosa, lymphoid tissue (adenoids, lingual tonsils), minor salivary glands
pathology in the mucosal space
nasopharyngeal ca, squamous cell ca, lymphoma, minor salivary gland tumors, juvenile angiofibroma, rhabdomyosarcoma
contents of the parapharyngeal space
fat, trigeminal nerve (V3), internal maxillary artery, ascending pharyngeal artery
pathology in the parapharyngeal space
minor salivary gland tumor, lipoma, cellulitis/abscess, schwannoma
contents of the parotid space
parotid gland, intraparotid lymph nodes, facial nerve (VII), external carotid artery, retromandibular vein
pathology in parotid space
salivary gland tumors, metastatic adenopathy, lymphoma and parotid cysts
contents of the carotid space
cranial nerves (IX and XII), sympathetic nerves, jugular chain nodes, carotid artery, jugular vein
pathology in the carotid space
schwannoma, neurofibroma, paraganglioma, metastatic adenopathy, lymphoma, cellulitis/abscess, meningioma
contents of the masticator space
muscles of mastication, ramus and body of mandible, inferior alveolar nerve
patholgy in the masticator space
odontogenic abscess, osteomyelitis, direct spread of squamous cell ca, lymphoma, minor salivary tumor, sarcoma of muscle or bone
contents of the retropharyngeal space
lymph nodes (lateral and medial retropharyngeal), fat
pathology in retropharyngeal space
metastatic adenopathy, lymphoma
contents of the prevertebral space
cervical vertebrae, prevertebral muscles, paraspinal muscles, phrenic nerve
pathology in prevertebral space
abscess/cellulitis, osseous metastasis, chordoma, osteomyelitis, cellulitis, abscess
these space includes all structures on the airway side of the pharyngobasilar fascia
superficial mucosal space
represents the suprior aponeurosisof the superior pharyngeal constrictor muscle, which inserts into the skull base. this tough fascia separates the mucosal spae from the surrounding parapharyngeal space
pharyngobasilar fascia
most common benign lesions arising the mucosal space are
Tornwaldt cysts and lesions related to the minor salivary gland tissue
these are sharply marginated and are found in the mdiline with high SI on T2. they are believed to be remnants of notochordal tissue aberrantly located in the nasopharynx and have an incidence of approximately 1 to 2 % in normal patients
Tornwaldt cyst
lesions arising from the minor salivary glands include
retention cysts and benign neoplasms
these cysts represents obstructed glands similar to those found within the paranasal sinuses
retention cysts
most common bening neoplasm in the mucosal space is the
beningn mixed cell tumor (pleomorphic adenoma)
triad of radiographic findings in malignant lesion of mucosal space
superficial nasopharyngeal mucosal asymmetry, ipsilateral retropharyngeal adenopathy and mastoid opacification
important early warning sign in malignancy of mucosal space
mastoid opacification; suggests potential dysfunction of the eustachian tube, frequently the result of tumor infiltration of the tensor veli palatini muscles
this MR sequence is an invaluable tool allowing detection of infiltrating pathology as the normally bright fat is replaced. it also allows subtle detection of perineural spread of neoplasms, particularly along cranial nerves extending into the skull base
precontrast T1
this is the most common minor salivary gland malignancy which has a marked perineural spread
adenoid cystic carcinoma
true or false: altho smoking and alcohol abuse are often associated with squamous cell ca, they have no causal association with nasopharyngeal ca
true
this immunoglobulin antibodies to Epstein-Barr virus have been associated with nasopharyngeal ca
IgA
a triangular, fat-filled compartment that extends from the skull base to the submandibular gland region. it is located at the center of the surrounding spaces and is compressed or infiltrated in a charateristic fashion by masses originating from the various spaces. it serves as important landmark of mass effect in the deep face
parapharyngeal space
spaces surrounding the parapharyngeal space
carotid space posteriorly, parotid space laterally, masticator space anteriorly, superficial mucosal space medially
mass in the carotid space will displace the parapharyngeal space
anteriorly
mass in the parotid space will displace the parapharyngeal space
medially
mass in the superficial mucosal space will displace the parapharyngeal sapce
laterally
mass in the masticator space will displace the parapharyngeal space
posteriorly
carotid space lesions can displace what structures
pps anteriorly, may separate or anteriorly displace carotid and jugular vein. they sometimes displace the styloid process anteriorly, which narrows the stylomandibular notch
how does deep parotid space lesions affect the stylomandibular notch
widens the stylomandibular notch
most common variation in the vascular anatomy of neck
asymmetry of the IJV; most commonly right being larger of the two
these are vascular tumors that arise form neural crest cell derivatives
paragangliomas
when paraganglioma arise from the carotid body, it is called
carotid body tumor
paragangliomas that arise from the ganglion of vagus nerve
glomus vagale tumors
paraganglioma that arise along the jugular ganglion of the vagus nerves
glomus jugular tumors
paraganglioma that arise around the Arnold and Jacobson nerves in the middle ear
glomus tympanicum tumors
presents with a painless, slowly progressive neck mass that may be pulsatile with an associated bruit. because these lesions are located within the carotid sheath, there are often associated with slowly progressive cranial neuropathies (cranial nerves IX and XII)
paragangliomas
are paragangliomas mostly solitary or multiple
multiple
angiographically, paragangliomas are
very vascular, with a strong blush in the capillary phase
tx for paraganglioma
embolization and surgical resection
differentiating paragangliomas and neuromas in MR
paragangliomas are characterized by multiple flow void and prominent enhancement, but neuromas usually do not demonstrate flow voids and can be cystic
these are encapsulated tumors that arise from nerve sheath covering and do not infiltrate the substance of the nerve
schwannomas
schwannoma within the carotid space often arise from the ___ and present as benign neck mass
vagus nerve
in contrast to schwannomas, these are not encapsulated and usually occur as multiple lesions that permeate the substance of the nerve fibers
neurofibromas
principal malignancy of the carotid space
squamous cell nodal metastasis
serves as the final common efferent pathway of the lymphatic drainage from the head and neck
deep cervical jugular nodal chain
the only salivary gland with lymph nodes contained within its capsule. this reflects the embryogenesis of the parotid gland, the late encapsulation of which results in the presence of lymph nodes within the gland parenchyma
parotid gland
most of the benign parotid tumors are
benign mixed-cell tumors (pleomorphic adenomas)
second mass common benign salivary gland tumor is
Warthin tumor
malignant tumors of the parotid gland include
adenocystic carcinoma, adenocarcinoma, squamous cell carcinoma and mucoepidermoid carcinoma
feature predictive of malignancy in the neck is
infiltration into deep neck structures, such as the masticator or parapharyngeal space. clinical involvement of the facial nerve is another ominuous finding suggestive of malignancy
parotid cysts aka lymphoepithelial cysts has been seen in these conditions ___. they are believed to be the result of partial obstruction of the terminal ducts by surrounding lymphocytic infiltration
collagen vascular disease (Sjogren syndrome) and in patients with AIDS
this space is formed by a superficial layer of deep cervical fascia that surround the muscles of mastication and mandibile. it extends from the angle of mandible superiorly to the skull base and over the temporalis muscle
masticator space
muscles of mastication
temporalis, medial and lateral pterygoids, masseter
most masses of masticator space are of what origin
infectious
pseudotumors of the masticator space are common which include
accessory parotid glands as well as marked muscle hypertrophy resulting from bruxism
asymmetry of the muscles of mastication may result from unilateral atrophy, owing to compromise of what nerve. this is also most commonly seen in patients with head and neck neoplasms with perineural extension along this nerve
mandibular division of trigeminal nerve (V3)
complication of oropharyngeal or nasopharyngeal lesions
may spread along V3, allowing tumor to ascend through the foramen ovale into the cavernous sinus
primary malignancies of masticator space
sarcoma, chondroid or nerve elements, non-Hodgkin lymphoma
presents as a well-circumscribed parotid mass which is bright on T2 and demonstrates heterogeneous contrast enhancement. these imaging features are consistent with a
benign pleomorphic adenoma
may present as innumerable tiny parotid cysts reflecting the lymphocytic infiltration of the exocrine glands, which causes lympahtic obstruction and cyst formation
parotid cysts or benign lymphoepithelial cysts
signs of perineural spread in MRI
nerve thickening, widening of the neural foramen, loss of fat surrounding the nerve, abnormal perineural contrast enhancement
potential space that lies posterior to the superficial mucosal space and pharyngeal constrictor muscles and anterior to the prevertebral space
retropharyngeal space
a mass within this space results in characteristic posterior displacement of the prevertebral muscles
retropharyngeal space
this space serves as a potential conduit for the spread of tumor or infection from the pharynx to the mediastinum
retropharyngeal space
most lesions of the retropharyngeal space are a result of
infection or nodal malignancy
this space is most often involved with nodal malignancy because of lympho,a or metastatic head and neck squamous cell carcinoma
retropharyngeal space
these retropharyngeal nodes are normal when seen in younger patients but must be viewed with suspicion in individuals older than 30 y.o
lateral retropharyngeal nodes aka nodes of Rouviere
this is formed by the prevertebral fascia, which surrounds the prevertebral muscles. masses on this space displace the prevertebral muscles anteriorly. this allows prevertebral lesions to be easily differentiated from retropharyngeal processes.
prevertebral space
structures that give rise to most pathologies in this space are the cervical vertebral bodies. any process that involves the vertebral bodies, such as tumor (metastasis, chordoma, etc) or osteomyelitis, may extend anteriorly to involve this space
prevertebral space
transpatial diseases refers to masses that may not be localized to one of the neck spaces, but are often secondary to lesions involving anatomic structuresn that normally traverse spaces of the head and neck, examples of which are
lymphatic masses (lymphangiomas), neural masses (neurofibroma, schwannoma, perineural spread of tumor) and vascular masses (hemangioma)
these congenital neck abnormalities look quite similar on MR. both of them have increased SI on T2 and are infiltrative. They may have phleboliths and evidence of blood degradation. both entities should be considered in a patient with a history of chronic facial swelling and who shows CT or MR evidence of an infiltrative process that traverses several spaces
lymphangiomas and hemangiomas
these conditions have a particularly proclivity for perineural spread of disease, which serves as a hallmark of these diseases.
fungal infections, squamous cell carcinoma, adenoid cystic carcinoma
if a patient with a known head and neck primary neoplasm or immunocompromised status (susceptible to fungal infections) presents with facial numbness or dyesthesias, this is highly suggestive of
perineural spread of disease
contains the precricoid (Delphian), pretracheal, paratracheal, and perithyroidal nodes, including those along the recurrent laryngeal nerves, and the external branch of the superior laryngeal nerve. parathyroid glands are also normally located here
central neck (level VI)
superior margin of thyroid and lymph node basins
level of hyoid bone
inferior margin of thyroid and lymph node basins
level of brachiocephalic vessels
lateral margins of thyroid and lymph node basins
medial aspect of the common carotid arteries
serves as the final common afferent pathway for lymphatic drainage of the entire head and neck. this nodal chain folows the oblique course of the jugular vein beneath and adjacent to the anterior border of SCM
internal jugular nodal chain
highest node of the IJ chain
jugulodigastric node
this is immediately posterior to the submandibular gland and provides lymphatic drainage from the tonsil, oral cavity, pharynx and submandibular nodes
jugulodigastric node
most LN of the head and neck should be equal to or less than 1 cm in short axis except the ___ and ____ nodes which may normally measure up to 1.5 cm in diameter
jugulodigastric and submandibular nodes
several LN features that suggest malignancy are
peripheral nodal enhancement with central necrosis, extracapsular spread with infiltration of adjacent tissues and matted conglomerate mass of nodes
contains both the extraconal and intraconal spaces
retrobulbar space
extraconal and intraconal spaces are separated by the muscle cone or
“annulus of Zinn”
this muscle cone is formed by the extraocular muscles (superior, inferior, medial and lateral rectus; superior oblique and levator palpebrae superior) and a fibrous septum. together these structures form a cone with its base at the posterior of the globe and its apex at the superior orbital fissure
Annulus of Zinn
composed of the optic nerve and surrounding perioptic nerve sheath
optic nerve sheath complex
this is an extension of the brain enveloped by CSF and leptomeninges, which form the optic nerve sheath
optic nerve
CSF space that envelopes the optic nerve is continuous with the intracranial subarchnoid space. therefore, if a lesion arises from the optic nerve sheath complex, the most common lesion is either an ____ or ______
optic nerve glioma or optic sheath meningioma
most common tumor of the optic nerve and typically occurs during the first decade of life. it has high association with NF1, particularly when there is bilateral optic nerve involvement, these lesions are low-grade pilocytic astrocytomas
optic nerve glioma
characteristic imaging finding in optic nerve glioma
enlarged optic nerve sheath complex that may be tubular, fusiform or eccentric with kinking
some optic nerve gliomas have extensive associated thickening of the perioptic meninges. histologically, this reflects peritumoral-reactive meningeal changes, which has been termed ______. this finding is often seen in patients with neurofibromatosis
“arachnoidal hyperplasia” or “gliomatosis”
arise from hemangioendothelial cells of the arachnoid layer of the optic nerve sheath. these lesions assume a circular configuration and grow in a linear fashion along the optic nerve. they also demonstrate a characteristic “tram track” pattern of linear contrast enhancement, because the nerve sheath enhances, rather than the nerve itself
optic sheath meningiomas
difference between optic nerve glioma and optic sheath meningioma
meningiomas may invade and grow through the dura, resulting in an irregular and asymmetric appearance. In addition, optic sheath meningiomas may be extensively calcified, whereas optic nerve gliomas rarely have any calcification
these conditions may mimic “tram track” appearance of optic nerve sheath meningiomas
sarcoidosis, leukemia or lymphoma
important differential diagnostic consideration for enhancement of the optic nerve sheath is
optic neuritis
this condition demonstrates abnormal T2 hyperintensity and contrast enhancement as a result of inflammation of the optic nerve itself. it presents with acute visual deficit, often described as “blurring” of vision and can be the first sign of multiple sclerosis. approximately 20% of patients with MS initially presents with an episode of this condition
optic neuritis
vascular lesions that may develop in the orbit
capillary hemangioma, lymphangioma, cavernous hemangioma and varix
this vascular lesion develop in infants and are diagnosed within the first weeks of life. altho these lesions may grow rapidly in size, they typically plateau during the first year or two then regress spontaneously. on imaging studies , it appears as infiltrative soft tissue complex, often with multiple vascular flow voids
capillary hemangiomas
vascular lesion that is one of the most common orbital tumors of childhood and occur in an older group of children (3 to 15 years). they are characterized by their propensity to bleed, and they often contain blood degradation products. an acute hemorrhage may result in marked expansion of the lesion with sudden proptosis
lymphangiomas
these are one of the most common orbital masses in adults. in contrast to the other vascular lesions of the orbit, these are characterized as a sharply circumscribed, rounded mas. these lesions demonstrate diffuse enchancement, sometimes with a mottled pattern.
cavernous hemangioma
it is an enormously dilated vein that is characterized by it marked change in size with the Valsalva maneuver
venous varix
pathologies in the superior ophthalmic vein include
thrombosis and enlargement
this condition often occurs in conjunction with cavernous sinus thrombosis and presents as loss of normal flow void, with signal intensity related to the age of the thrombus
superior ophthalmic vein thrombosis
enlargement of the superior ophthalmic vein may also be seen with
cavernous carotid fistulas
this condition represent direct or indirect communication between the internal carotid artery and venous cavernous sinus. These are either spontaneous or posttraumatic, and patients amy present with pulsating exophthalmos and bruit
cavernous carotid fistulas
these are two important orbital lesions that may present with similar imaging findings.
pseudotumor and lymphoma
a poorly characterised condition that results from an inflammatory lymphocytic infiltrate. this is the most common cause of an intraorbital mass lesion in the adult population. it is often rapidly developing and presents with painful proptosis, chemosis and ophthalmoplegia
idiopathic inflammatory pseudotumor
third most common adult orbital mass lesion, following pseudotumor and cavernous hemangioma
lymphoma
this MR finding is suggestive of orbital pseudotumor
dark signal on T2
this drug may be valuable in differentiation orbital lymphoma from pseudotumor. it can eliminate pseudotumor in lasting effect while it may be short-lived response in lymphoma
steroids
when a diffusely infiltrative mass is encountered in a young child anywhere in the head and neck region, including the orbits, this should be considered
rhabdomyosarcoma
age, imaging features and morphology of orbital capillary hemangioma
<1 y.o, flow voids, infiltrative lesion
age, imaging features and morphology of orbital lymphangioma
3-15 y.o, blood products, multiloculated, lobular mass
age, imaging features and morphology of orbital cavernous hemangioma
adults, well-circumscribed mass, rounded mass
age, imaging features and morphology of orbital varix
any age, dilated vein, may enlarge with valsalva maneuver, vascular structure
most freq cause of unilateral or bilateral proptosis in adults. this condition is the result of an inflammatory infiltration of the orbital muscles and orbital connective tissues
thyroid ophthalmopathy (Grave’s disease)
imaging findings in this condition include enlargement of the EOM with sparing of the tendinous attachments of the globe
thyroid ophthalmopathy (Grave’s disease)
this condition involves the muscle attachments of the globe, in contrast to thyroid ophthalmopathy (Grave’s disease)
orbital pseudotumor
muscles involved in decreasing order of muscle involvement in thyroid ophthalmopathy (Grave’s disease)
“I’m Slow” – inferior, medial, superior and lateral rectus
extraconal space primarily contains
fat and lacrimal gland
lesions arising from the extraconal space are primarily what in origin
lacrimal in origin
lesions of the lacrimal gland are very nonspecific, but can be divided into
inflammatory and neoplastic types
neoplasms of the lacrimal gland include
epithelial and lymphoid tumors
these are any lesions that arise from the salivary glands, such as benign mixed-cell tumor or adenoid cystic carcinoma
epithelial tumors
lymphoid tumors of the lacrimal gland include
lymphoma and pseudotumor
most common primary ocular malignancy in pediatric age group and presents characteristically with leukocoria (white pupillary reflex) and a calcified ocular mass
retinoblastoma
common ocular pathology in adults includes
retinal and choroidal detachment, uveal melanoma and metastasis
other globe conditions in pediatric patients aside from the common retinoblastoms
persistent hyperplastic primary vitreous tumor, Coat’s disease, retinopathy of prematurity and endophthalmitis secondary to Toxocara canis
characteristic finding in orbital dermoid
presence of fat
in children, neck masses tend to be benign, including both congenital and inflammatory lesions. when malignancy is entertained, the most common lesion in the pediatric age group is
lymphoma, followed by rhabdomyosarcoma
this accounts for about 90% of congenital neck lesions, and usually are found in children but may be seen in adults. it represents an epithelium-lined tract along which the primordial thyroid gland migrates
thyroglossal duct cysts
thyroglossal duct originates from the ______, extends anterior to the ________ and _______, and ends at the level of ______
foramen cecum (at the tongue base), extends anterior to the thyrohyoid membrane and strap muscles, and ends at the level of thyroid isthmus
thyroglossal duct normally involutes by
8 to 10 weeks of gestation
thyroglossal duct is lined by this epithelium, that is why any portion of the duct that fails to involute may give rise to a cyst or sinus tract
secretory epithelium
75% of thyroglossal duct cysts are located where
midline, and most are located at or below the level of the hyoid bone, in the region of the thyrohyoid membrane
most common midline neck mass
thyroglossal duct cyst
tx of choice for thyroglossal duct cyst
surgery
imaging findings in thyroglossal duct cyst
cystic masses with a uniformly thin peripheral rim of capsular enhancement, with occasional septations
represents an abnormal dilatation of the appendix of the laryngeal ventricle
laryngocele
structure that separates the false and true vocal cords and anteriorly ends in a blind pouch termed the appendic
laryngeal ventricle
it develops as a consequence of chronically increased intraglotitic pressure, as may be seen in musicians (wind instruments)), glass blowers, or excessive coughers
laryngocele
laryngoceles are classified as ___ , ____ or mixed, according to their location to the thyrohyoid membrane
internal, external or mixed
laryngocele that are confined to the larynx
internal
laryngocele that protruce above the thyroid cartilage and through the thyrohyoid membrane, typically present as a lateral neck mass near the hyoid bone
external
most commonly, laryngoceles have portions that are both in and outside of the thyrohyoid membrane and are called ___
mixed
laryngoceles that develop without a known predisposing factor should raise the suspicion of an underlying
neoplasm, osbtructing the laryngeal ventricle
structures of the face and neck are derived from _____
branchial cleft apparatus, which consists of six branchial arches
may develop if there is failure of the cervical sinus or pouch remnants to regress
branchial cleft cyst, sinus or fistula
majority of the branchial anomalies are from the
second branchial cleft
course of the second branchial cleft begins at the
base of the tonsillar fossa and extends between the internal and external carotid arteries, anterior to the middle portion of the sternocleidomastoid muscle and lateral to the internal jugular vein at the level of carotid bifurcation
usual clinical presentation is that of a painless neck mass along the anterior border of the sternocleidomastoid muscle, presenting during the first to third decade
branchial cleft cyst
branchial cleft cyst may enlarge with
URTI
congenita malformation of the lymphatic channgels, these lesions are benign and nonencapsulated. histologically ther are classified as capillary, cavernous or cystic
lymphangiomas
composed of capillary-size, thin-walled lymphatic channels
capullary hemangiomas
composed of moderately dilated lymphatics with a fibrous adventitia
cavernous lymphangiomas
represent enormously dilated lymphatic channels
cystic hygromas
lymphatic system develops from
primitive embryonic lymph sacs that are in turn derived from the venous system
represent sequestrations of the primitive embryonic lymph sacs. if this defect is localized, the result is a
isolated cystic hygroma
time of greatest lymphatic development is at this age and therefore, most of the lymphangiomas present at this age
2 y.o
lymphangiomas and cystic hygromas are commonly seen in what region of the neck
posterior triangle
how to differentiate lymphangiomas and cystic hygromas from from other cystic lesions of the neck
lymphangiomas and cystic hygromas are easily compressible, they tend not to displace adjacent soft tissue structures
