Head and Neck Flashcards
Cholesterol granuloma
Smooth expansile, well marginated petrous apex lesion
High T1 and T2
Doesnt suppress fat
No diffusion restriciton
Cholesteatoma
Petrous apex lesion with smooth expansile bony changes
low T1, high T2
without central parenchymal enhancement restrict diffusions
Smooth lobulated cystic expansion of the petrous apex ?
Cephalocele
-Hernation of CNS through defect in cranium.
-In petroux apex, no brain tissue, just CSF/cystic, herniation from meckels cave into the petrous apex
Permeative bone destruction of the posterior petrous ridge. T2 Bright and intense enhancement. lesion extending into the CPA?
Endolymphatic sac tumour
**Strongly associated with VHL **
Very vascular often with flow voids.
Retrolabyrinthine: Posteromedial T-bone
Large lesions can involve the CPA cistern, middle ear/mastoid, & jugular foramen
Bone CT: Central intratumoral bone spicules & posterior rim Ca⁺⁺
MR: High-signal foci on unenhanced T1 (haemorrhage and cholesterol). Heterogenous enhancement
Other lesion cause for permeative destruction of petrous apex?
- Paraganglioma of Glomus Jugulare
Invade the occipital bone/jugular foramen first . Jugular spine eroded
Then spread superolateral to PA and middle ear.
T1
“Salt” refers to hyperintense foci within tumor related to hemorrhage or slow flow.
= Hyperintense foci (quite rare)
+
“Pepper” refers to numerous hypointense foci within tumor, representing high-velocity arterial flow voids
=Hypointense foci common
T1+ C = intense enhancment
Sharply marginated, enlarged JF on bone CT
Fusiform, enhancing mass enlarging JF on T1WI C+ MR?
Jugular Foramen Schwannoma
NO Flow voids
Cranial nerve palsy of 9,10,11 (Vernet syndrome)
Permeative-sclerotic involvement of bone around JF on CT
Enhancing JF mass spreading centrifugally along dural surfaces on enhanced MR
Jugular Foramen Meningioma
permeative** sclerotic** changes along the JF and lateral clivus
Extend into middle ear, jugular tubercle marrow space and nternal auditory canal
Progressive sensorineural hearing loss. CT shows enlarged vestibular aqueduct?
Large vestibular aqueduct syndrome - aka Pendred syndrome
Commonest cause congenital sensorineural hearing loss
Axials - The vestibular aqueduct is never larger than the adjacent posterior semicircular canal
Conductive hearling loss in an adult female?
Otosclerosis
Temporal bone CT: Lucent (otospongiotic) foci involving bony labyrinth
Usually in context of normally aerated middle ear
Features of pagets disease of the skull?
- Well defined and sharp margin of radiolucency affecting the frontal and occipital bones = OSTEOLYSIS CIRCUMSRIPTA
- Thickened and expanded sclerotic skull.
OLD person 80s
Pagets skull related complications ?
**Deafness
Cranial nerve paresis
Basilar invagination = hydrocephalus = brainstem compression
Secondary High grade osteosarcoma
Young 20-year-old with lytic skull lesion with ground glass appearance?
Fibrous dysplasia
Spares the optic capsule - no hearing issues
**McCune-Albirght syndrome = **
Multi-focal fibrous dysplasia, cafe-au-lait spots and precocious puberty
Teenage male with nose bleeds. Mass centred in the sphenopalatine foramen and extends into the pterygopalatine fossa?
Juveline nasal angiofibroma
Very vascular.
Blood supply from the ascending pharyngeal artery and or internal maxillary artery.
Not IR. 80% cured by radiation!
Adult 30-40s with nasal obstrictive symptoms. large solitary opacification extending into the nasal cavity from the maxillary sinus with widening of the maxillary antrum?
Antrochoanal polyp
effectively a large solitary sinonasal polyp
**No bone destruction, smooth enlargement of the sinus. ** ‘Dumbell shape’
Peripheral enhancement.
Water signal on CT/MRI
Sinus mass arising from the lateral wall of middle meatus, with extension into the antrum?
Inverting Papilloma
Cerebriform pattern of enhancement on MRI.
Focal hyperostosis on CT suggests tumour origin/stalk,
Destruction of the medial wall of the maxillary sinus
Trapped sectrions
10% harbour a SCC
Soft tissue mass in the maxillary antrum with destruction of the sinus walls?
SCC
Can extend into orbits, brain etc
Decreases T2 signal relative to other sinus pathologies = hypercellular
maxillary antrum is involved in 80% of cases
Note Sinonasal Adenocarcinoma - predilection for ethmoid sinus and enhances more.
Impossible to distinguish from SNUC
20 year old Dumbbell shaped mass with waist at the cribriform plate , with upper portion in the anterior cranial fossa and lower portion in the upper nasal cavity?
Esthesioneuroblastoma
Bimodal -m20s or 60s
Avid homogenous enhancement
Somatostatin positive = uptake on octeride scan
Homogeneous soft tissue mass with predilection for nasal cavity, bone destruction and low signal on T2?
Sinonasal lymphoma
Also low on T2 and bone destruction like SCC but = Nasal cavity
SCC = Maxillary antrum
Very nonspecific imaging features
can mimic variety of neoplasms & aggressive inflammatory disorders
well circumscribed midline mass in the floor of the oral cavity predominantly of flood density with intralesional fat density cysts?
Floor of mouth dermoid
‘sack of marbles’
Epidermoid will ne homogenous fluid signal
Simple well-defined thin walled cyst in the sublingual space?
Rannula
Thin-walled SMS cyst with SLS tail = Diving rannula
Crossed mylohyoid
Most common location for ectopic thyroid tissue?
Tongue base - ‘Lingual thyroid’
Will be hyperdense like thyroid.
Anterior midline suprahyoid or midline/paramidline infrahyoid cystic neck mass?
Thyroglossal cyst
wall enhancement and soft tissue stranding = infected
Nodularity or Ca2+ suggests papillary carcinoma
Pleomorphic adenoma/Parotid Benign Mixed Tumor
Sharply marginated
intraparotid ovoid mass
uniform enhancement.
Very bright T2 signal
Small < 2cm - well defined
Large > 2cm - Lobulated
90% arise in superficial lobe.
Deep lobe = ‘pear shaped’ and displaces the PPS medially
Most common benign/any major and minor salivary gland tumour.
Can occur in SM and SL glands.
but parotid 90%
differentiate from a partoid warthins
- Pleomorphic adenoma can have CALCIFICATION
Second most common benign tumour in parotid gland?
Warthin
Only occur in parotid gland.
Usually solid/cystic, male and smoker.
Bilateral or multifocal (20%)
Imaging features of jugular foramen schwannoma
Sharply marginated, enlarged JF on bone CT
Fusiform, enhancing mass enlarging JF on T1WI C+ MR
No flow voids
Can have cystic changes
Not octreotide avid
Not all that vascular on angio
Imaging features of Glomus jugulare?
Mass in JF with permeative-destructive change of adjacent bone on CT
Multiple black dots (“pepper”) in tumor indicate high-velocity flow voids from feeding arterial branches on MR
Thin-walled, fluid- or air-filled lesion communicating with laryngeal ventricle,
Laryngocele
Stenosis at the laryngeal ventricle can be an obstruction from a tumour (15%)
+/- extra laryngeal extension through the thyrohyoid membrane
Most common benign tumor of the orbit?
Dermoid
Arises superior and lateral, arissing from the frontozygomatic suture.
Young child
What are some of the key differences between a orbital lymphangioma and a venus varix?
Lymphangioma
- malformed veins and lymphatics
- Money shot = they do not increase with the valsalva
-Fluid-fluid levels
- mutlilocuted cystic components
- transpatial involvement - pre, posr septal, intra and extra conal
Varix
-Veins only, weak wall and valves
- massive dilatation of orbital veins
- Distend with provocative measures
- imaging can look normal with no Valsalva
- Most common cause of spontaneous orbital haemmorhage
What is the most common vascular orbital lesion in adults?
orbital Cavernous venous malforation/cavernous haemangioma
Weak arterial supply - so slow enhancement with delayed washout - progressive fill in
classic lateral intraconal sparing orbital apex
Low T1 signal pseudocapsule
What are orbital findings associated with NF-1?
Orbital pathway glioma
-WHO grade 1 pilocyctic astrocytoma
-Expansion nd enlargement of the entire nerve
Plexiform neurofibroma (PNF)
-Serpentine, unencapsulated, infiltrative masses
- enlarge skull base foramina
sphenoid wing dysplasia - Cause pulsatile exophthalmos
buphthalmos (visible enlargement of the globe)
lisch nodules
Main causes of Leukocoria (loss of red eye reflex) in a child ?
Retinoblastoma
Coats disease
Persistent hyperplastic primary vitreous
Coats
-Normal-sized globe, hyperdense; no Ca⁺⁺
-Subretinal exudate with retinal detachment
PHPV
-Retrolental tissue & stalk
- small eye
Retinoblastoma
-Calcification present in vast majority
Masses in mandible
Odontoma -
- Most common lucent lesion in mandible
-Over time shows calcifications that coalesce to form a dense lesion with a lucent rim.
- 2nd decade of life
**-associated with gardners syndrome **
Ameloblastoma –
-Soap appearance, Multilocular , fluid levels
-classically arise near the angle of the mandible
-locally aggressive so additional features such as tooth
resorption and cortical erosion through the bone into adjacent tissues
Dentigerous cyst -
-Benign, developmental lucent lesion surrounding the crown of unerupted tooth.
-Also know as follicular cyst
-crown of a tooth projecting in to the cystic space is pathognomonic
Periapical cyst
- any tooth
–often the result of a **dental infection **and an associated dental cavity may be seen
Odontogenic keratocysts
-destructive, unilocular lesions centered about the ramus or body of the mandible
-Unlike a dentigerous cyst, an odontogenic keratocyst can erode
through the cortex of the mandible
-multiple odontogenic keratocysts = basal cell nevus syndrome
Benign cyst of jaw with aggressive behavior and high recurrence rate
Odontogenic Keratocyst
If multiple, with midface hypoplasia, calcification of falx, frontal bossing and prognathism = GORLIN basal cell naevus syndrome
Orbital lesions
see picture
Deep spaces neck and displacement of PPS
Masitactor space - Posterior-medial
Parotid space - Antero-medial
Carotid - antero-lateral
Pharyngeal muscosa - Posterio-lateral
Boundaries of Nasopharynx, oropharynx and hypopharynx?
oropharynx divided from hypopharynx by valleculae.
