Sinus and Anterior Skull Base Flashcards
1
Q
Esthesioneuroblastoma overview
A
rare, Olfactory mucosa tumor
AKA Olfactory neuroblastoma
Typically seen in adolescent or middle aged patients w/ mild epistaxis and nasal obstruction
2
Q
Esthesioneuroblastoma imaging
A
- Best imaging: Enhanced MR with bone only CT
- Characteristics: Dumbbell-shaped mass with “waist” at cribriform plate
- Bone remodeling died with bone destruction, esp of cribriform
3
Q
Esthesioneuroblastoma staging
A
- Kadish staging system good for prognosis
- A: limited to nasal cavity
- B: Nasal cavity+ paranasal sinuses
- C: Extends to skull base, intracranially, orbit
- D: cervical mets
4
Q
Esthesioneuroblastoma general tx and recurrence/mets rate
A
- TX: Surg+ Chemo
- 5 yr survival: 75-77%
- Recurrence 30%
- Mets in 10-30%
5
Q
Sinus mass DDX
A
Esthesioneuroblastoma
SCC
Sinonasal adenocarcinoma or minor salivary tumors
Sinonasal NHL
Sinonasal Melanoma (Intense on T1 MRI)
Sinonasal undifferentiated carcinoma
JNA in young men
6
Q
Frontal Sinus normal variations
A
Absent 5%
Unilateral 15-20%
7
Q
Frontal sinus pneumatizes from ethmoid with 4 Pits
A
Lots of variation
1st –> Agger nasi cell (most consistent, 98% have it)
2nd –> Front sinus
3rd and 4th–> Supraorbital cells
8
Q
Kuhn and Bohler Classification
A
Drainage pattern of frontal sinus
1: Single frontal recess above agger nasi cell
2: tier of cells in frontal recess above agger nasi
3: Large cell pneumatizing from frontal recess into frontal sinus
4: cell totally isolated within frontal sinus
9
Q
Frontal Recess anatomy
A
Middle turbinate is medial
Lamina papyracea is lateral
Posteriorly is bulla lamella (if this doesnt reach skull base, the recess may open into suprabullar recess)
Frontal process of maxilla is anterior
10
Q
Weakest point of ethmoid bone
A
Lateral lamella of ethmoid
11
Q
Frontal sinus drainage
A
- MC medially 80%
- Directly into Agger nasi (10%)
- Posteriorly (10%)
12
Q
Maxillary Sinus Hypoplasia
A
Bolger et al
Import bc there’s an increase risk for surgical damage to orbit
3 types
I: Mild, elongated orbit, atrophic uncinate
II: Very small sinus
III: All bone, no sinus
13
Q
Anterior ethmoid arteries
A
Always behind optic nerve
“Nipple sign” on CT coronals
14
Q
Ethmoid Bulla
A
Most constant and largest anterior ethmoid cell
Projects inferomedially over hiatus semilunaris
MC drains into retrobulbar space but varies
15
Q
Basal Lamellae
A
Where middle turb attaches to orbit
Separates anterior from posterior ethmoids
16
Q
Haller cells
A
Infraorbital air cell
Can impinge on ostiomeatal complex blocking maxillary sinus drainage
17
Q
Sphenoid Sinus safety
A
Axial scans tell you about carotid protection
If sphenoid septum attaches to carotid canal
18
Q
Ostiomeatal complex 5 structures
A
- Maxillary ostium
- Infundibulum
- Ethmoidal bulla
- Uncinate process
- Hiatus semilunaris
19
Q
Infundibulum
A
Uncinate is medial
Orbital plate of ethmoid id lateral
Common channel draining the ostia of the maxillary antra and anterior ethmoid air cells to the hiatus semilunaris
Often continuous with the frontonasal recess
20
Q
Uncinate process
A
Arises from posteromedial aspect of nasolacrimal duct
Anterior boundary of hiatus semilunaris
21
Q
Hiatus semilunaris
A
final drainage passage, b/t ethmoid bulla superiorly and free edge of uncinate process
22
Q
Chordoma Imaging CT and MRI features
A
CT:
well circumscribed, destructive lytic lesion
irregular intratumoral calcifications
Moderate enhancement
Can have positive thumb sign (mass imprints on pons)
MRI
T2: Highly enhancing
T1 w/ contrast: honeycomb appearance
T1: Low intensity
23
Q
Chordoma Pathophysiology and activity
A
Embryonic remnants of the primitive notochord (earliest fetal axial skeleton, extending from the Rathke’s pouch to the coccyx)
Extradural and result in local bone destruction
Locally aggressive, but uncommonly metastasise
30-35% of them are sphenoid-occipital
The rest are vertebral or sacrocoxygeal
24
Q
Clival mass DDX
A
Chordoma chondrosarcoma of skull base plasmacytoma meningioma of skull base pituitary macroadenoma ecchordosis physaliphora
25
7 segments of the ICA
| Mnemonic and segments
* Mnemonic: C'mon Please Learn Carotid Clinical Organizing Classification. Bouthillier classification
* C: cervical segment
* P: petrous segment
* L: lacerum segment
* C: cavernous segment
* C: clinoid segment
* O: ophthalmic segment
* C: communicating segment
26
Petrous Apex DDX
* asymmetrical marrow
* petrous apex cephalocoele
* petrous apicitis
* congenital cholesteatoma
* cholesterol granuloma: most common cystic appearing lesion
* mucocoele of petrous apex
* benign tumours
* meningioma
* schwannoma
* malignant tumours
* skull base chondrosarcoma: MC solid lesion
* skull base chordoma: often midline but can involve the petrous apex
* plasmacytoma
* metastatic lesion
* Langerhans cell histiocytosis
* aneurysm of terminal internal carotid artery
27
Petrous apex cephalocoele
rare form of cephalocoele centered typically in the posterolateral part of Meckel cave with variable extension into the petrous apex. They can be unilateral or bilateral (commoner)
Usually asymptomatic, but can p/w SNHL, trigem neuralgia
28
Petrous apicitis pathophys and S/s
Infection with involvement of bone at the very apex of the petrous temporal bone.
Usually 2/2 otomastoiditis
S/S:
- deep facial pain due to inflammation of the adjacent dura and trigeminal nerve in Meckel's cave
- abducens nerve palsy (see Gradenigo syndrome) due to involvement of Dorello's canal
29
Cholesterol Granuloma Overview
Middle ear granulation tissue which is particularly prone to bleeding, and is a frequent cause of a hemotympanum
30
Gradenigo Syndrome
Triad. "classic presentation of petrous apicitis"
1. petrous apicitis
2. abducens nerve palsy, secondary to involvement of the nerve as it passes through Dorello canal
3. retro-orbital pain, or pain in the cutaneous distribution of the frontal and maxillary divisions of the trigeminal nerve, due to extension of inflammation into Meckel cave
31
Petrous Apicitis Imaging and tx
```
CT temporal bone
erosive lysis with ill-defined irregular edges
MRI:
T1: fluid signal (low to intermediate)
T2: fluid signal (hyperintense)
T1 C+ (Gd): peripheral enhancement.
```
TX:
IV Abx, surgery if drainage is required
32
Cholesterol Granuloma S/s based on location
if in the middle ear
conductive hearing loss
dizziness
cranial nerve dysfunction, e.g. CN VII
```
if at the petrous apex
asymptomatic
conductive hearing loss due to middle ear effusion
cranial nerve dysfunction (e.g. CN VI)
tinnitus
```
if in the mastoid
asymptomatic
headache
33
Cholesterol Granuloma Imaging MRI: T1/T2/T1+c/DWI
T1: overall high signal due to cholesterol component and methaemoglobin +/- low signal rim due to hemosiderin rim, and thinned adjacent bone***
```
T2
central high signal +/- peripheral low signal due to hemosiderin rim
thinned adjacent bone
does not attenuate on FLAIR
fat supression: remain high signal
```
T1 C + (Gd): no central enhancement although faint peripheral enhancement may be difficult to see due to intrinsic high T1 signal of lesion which is not saturated (not an adipose tissue)
DWI/ADC: no restricted diffusion
34
Cholesterol Granuloma Imaging CT
Expansile well marginated lesion with thinned overlying bone.
This may be dehiscent when the lesion is large. Faint peripheral enhancement post contrast may be seen
35
Cholesterol Granuloma TX
TX if symptomatic
Surgery treatment of choice
Need to excise the cyst wall
Recurrence common
36
Allergic Fungal Sinsusitis Overall and Pathophys
Represents 5-10% of chronic hypertrophic sinus disease going to surgery. It is seen in young immunocompetent patients (mean age range 23-42 years)
AFS is an allergic reaction to aerosolized environmental fungi (type 1, IgE-mediated hypersensitivity reaction). Expansion and even erosion (20%) of the sinuses are characteristic
37
Allergic Fungal Sinsusitis Imaging CT
Near complete opacification. On unenhanced, the sinuses are typically opacified by centrally (often serpiginous) hyperdense material with a peripheral rim of hypodense mucosa.
Approximately 40% of patients may have each of the following features:
- expansion of an involved sinus
- remodeling and thinning of the bone sinus walls
- erosion of the sinus wall
38
Allergic Fungal Sinusitis Imaging MRI
Hypointensity on T1WI and T2WI is the most common finding.
T1: hypointense inflamed mucosal thickness. It can have multiple T1 appearances.
T2
usually a hyperintense peripheral inflamed mucosal thickness
low T2 signal or signal void is due to high concentration of various metals such as iron, magnesium and manganese concentrated by fungal organisms as well as high protein and low free water content in allergic mucin
T1 C+ (Gd):
an inflamed mucosal lining has contrast enhancement
no enhancement in the centre or majority of the sinus contents (c.f. neoplasms)
39
Acute Invasive Fungal Sinusitis Overall
* Most aggressive form of fungal sinusitis
* Immunocompromised susceptible (diabetics included)
* Significant morbidity and mortality (50-80%)
40
Acute Invasive Fungal Sinusitis Signs and symptoms and organisms
* Varies but rapid development of fever, facial pain, nasal congestion, epistaxis common
* Extends into orbit, cavernous sinus, intracranially
* CN deficits, vision deficits common
* Can disseminate within days
* Aspergillus (often in neutropenic)
* Zygomycetes (Mucor and Rhizopus included) usually in diabetic
41
Acute Invasive Fungal Sinusitis Imaging CT
* Does NOT demonstrate hyper dense material within sinus on non-con
* unlike chronic invasive
* Bony changes
* Hypoattenuating mucosal thickening
* Opacification of sinus
* Bone destruction (varies in severity)
* Fat stranding outside of sinus perimeter
42
Acute Invasive Fungal Sinusitis Imaging MRI
* T1: intermediate low signal
* T2
* fungal mass is of intermediate to low signal
* often associated with fluid or blood elsewhere in the paranasal sinuses
* T1 C+ (Gd): absent sinus mucosal enhancement suggests necrosis; invasion outside the sinus appears as increased enhancement
43
Acute Invasive Fungal Sinusitis TX
* Aggressive surgical debridement
* Systemic antifungals (amphotericin)
* Correct DKA and neutropenia if present
44
Chronic Invasive Fungal Sinusitis Overall
* prolonged course than acute invasive fungal sinusitis, usually more than 12 weeks
* Patients are usually immunocompetent or have a milder level of immunocompromise.
45
Chronic Invasive Fungal Sinusitis Imaging CT
* relative lack of expansion of sinuses
* mottled lucencies or irregular bone destruction may be seen
* bone erosion being localised to the area of extra-sinus extension
* extra-sinus component of the disease being more than the intra-sinus component
* there may also be sclerotic changes in the bony walls of the affected sinuses representing chronicity of disease
46
Chronic Invasive Fungal Sinusitis Imaging MRI
* T1: iso- or hypointense signal
| * T2: usually markedly hypointense signal
47
Potts Puffy Tumor Pathophys
* non-neoplastic complication of acute sinusitis characterised by a primarily subgaleal collection, also subperiosteal abscess and osteomyelitis.
* infection erodes through the wall of the obstructed infected sinus to form a subperiosteal abscess
48
Potts Puffy Tumor: Associations, demographics, and MC organisms
* a/w Frontal sinus disease, also a/w trauma, cocaine/amphetamine, craniotomy
* Happens to everyone, but adolescents more common
* Micro
* Streptococcus sp
* Haemophilus influenzae
* Staphylococcus sp
* Klebsiella
49
Antrochoanal polyps Overview
Sinonasal inflammatory polyp arising from maxillary sinus antrum
3-6% of all sinanasal polyps
Usually in young males
50
Antrochoanal polyps s/s and tx
Usually unilateral, single polyp causing nasal obstruction
- Can extend to nasopharynx if large enough
R/o nasopharyngeal tumor (Usually JNA)
+ Dodd's sign or crescent sign (air b/t posterior pharyngeal wall and mass) which is negative for JNAs
TX: Complete surgical excision, may recur if incompletely excised
51
Sinus mucocele overview
Chronic, cystic lesion 2/2 obstruction of draining ostia from allergic or inflammation
Usually frontal or ethmoidal
S/S: depends on site of involvement. Facial swelling, pain, proptosis, diplopia, rhinorhea
52
Sinus mucocele: 2 types
Internal: Herniates into submucosal tissues adjacent to bony sinus wall
External: Herniates through bony wall
Expands in direction of least resistance
53
Sinus mucocele complications and TX
Pyocele
Meningitis
Brain abscess
Otherwise contents usually sterile
TX: Complete surgical excision
54
Furstenberg Test
Swelling or pulsating lesion following pressure on the ipsilateral jugular vein
--> Positive for an encephalocele
Negative for sinonasal CNS pathology like a nasal glioma
55
Rhinoscleroma: Overview and causative agent
Chronic granulomatous infectious disease of upper respiratory tract
Seen in lower socioeconomics+poor air quality in countries close to equator
Rare in US
Caused by Klebsiella rhinoscleromatis a GNR
56
Rhinoscleroma: TX
Tetracyclines, cipro
CO2 laser
Resolves well with antibiotics usually
57
Rhinosporidosis: Overview and causitive agent
Chronic upper respiratory tract infeciton causing polypoid masses
Endemic in India, Sri lanka, brazil
Thought to be zoonotic
Caused by Rhinosporidium seeberi, a fungus
58
Myospherulosis: Overview and causitive agent. TX?
Innocuous, iatrogenic
Pseudomycotic disease from petroleum based ointments interacting w/ RBCs
Usually p/w obstructive lesion
TX: Symptomatic
59
Rosai Dorfman Disease
Extradnodal Sinus Histiocytosis with massive lymphadenopathy (SHML)
Rare, idiopathic disorder
Extra-LN disease common in sinuses
TX: steroids, radiotherapy, chemo
60
Sinonasal Papillomas or Schneiderian: Overview, presentation, and 3 types
Benign neoplasm, mucosal in origin
S/S: obstruction, epistaxis, pain
Usually unilateral
HPV 6/11 have been implicated
3 histologic types
Septal
Inverted
Cylindrical
61
Sinonasal Papilloma TX and complications
Complete surgical excision with mucosal margins
Otherwise they will grow and can undergo malignant transformation (usually to SCC)
Septal papillomas rarely transform
62
Lobular Capillary Hemangioma: Overview, presentation
Benign, polypoid
Smooth, lobulated, polypoid red mass
MC p/w: Epistaxis, usually during pregnancy*
Regresses after parturition
TX: local surgical excision
63
Sinonasal hemangiopericytoma: Overview and presentation
Arises from pericytic cells (baroreceptors)
Can arise all over body (15-20% in H&N and of these 50% are in nasal cavity)
P/W: Epistaxis and nasal obstruction
Very vascular neoplasm
64
Sinonasal hemangiopericytoma: TX and prognosis
Surgical excision
Rarely metastasize (10%)
60% recur locally if inadequate excision
Radioresistant
65
Ameloblastoma: Overview
Benign, but locally invasive tumor
Originates from odontogenic epithelium
MC odontogenic tumor (but 1% of all jaw esions)
Can involve maxillary sinus but 80% involve mandible usually at unerupted 3rd molars
Usually slow growing
66
Ameloblastoma: TX
Complete surgical excision
Radio and chemo resistant
Mets are rare
Recurrences not uncommon
67
Sinonasal SCC: Overview, S/S, RFs
Malignant
MC epithelial neoplasm in sinonasal region
S/S: facial asymmetry, nasal obstrcution, epistaxis, purulent rhinorrhea
RFs: Nickel and thorotrast exposure
See H&N slides for more info
68
Sinonasal Mucosal Adenocarcinoma: Overview, S/S
Malignant epithelial neoplasm
3rd MC sinonasal malignancy
A/w wood dust exposure (900-1000x more likely)
Nonspec presentation (obstruction, epistaxis, etc)
Locally invasive w/ high recurrent rates
69
Inverted papilloma: Overview and imaging
Subtype of schneiderian papillomas
CT nonspecific but MRI very notable: ***"convoluted cerebriform pattern"
- alternating lines of high and low signal intensity
- seen in 50-100% of cases and is uncommon in other sinonasal tumours
```
T1: isointense to muscle
T2
generally hyperintense to muscle
alternating hypointense lines
T1 C+ (Gd)
heterogeneous enhancement
alternating hypointense lines
```
70
Inverted papilloma TX
Complete surgical excision via endoscopic or open approaches
Resect as they can transform malignantly or grow continuously
High recurrence rate
71
Sinonasal Mucosal Adenocarcinoma: Types and TX
Intestinal (a/w wood dust exposure)
Non-intestinal
TX:
Surgical excision, chemo rad depending on extent of disease
72
Sinonasal undifferentiated Carcinoma (SNUC): Overview, tx
Rare, highly aggressive sinonasal tumor. Relatively new pathologic distinction
Usually advanced at presentation
Usually from ethmoid sinuses
Poor survival
TX: Surgical
73
Sinonasal Mucosal melanoma: Overview
MC site for mucosal involvement of upper respiratory tract
Variable in appearance
NO correlation b/t size, location, or histology and survival
Met less frequently than SCC
74
Sinonasal Mucosal melanoma: TX and survival
TX: aggressive radial surgical excision w/ adjuvant radiotherapy
5 yr OS: 6-17%
2/3 of pts have recurrent disease w/in 1year post-surgery
