Sinus and Rhinology Flashcards
1
Q
Compare Yeast vs Mold
A
Yeast
- unicellular
- reproduce asexually by budding
- Pseudohyphae - when bud doesnt detach
Mold
- multicellular
- grow by branching - hyphae
2
Q
What is this structure?
A
Aspergillus
- Septated hyphae with branching at 45⁰
3
Q
What is this structure?
A
Mucormycosis
- Nonseptated hyphae with branching at 90⁰
4
Q
What are the types of non-invasive fungal infections?
A
Non-invasive
- Saprophytic fungal infestation
- Sinus fungal ball (mycetoma)
- Allergic fungal sinusitis
5
Q
What are the types of invasive fungal infections?
A
Invasive
- Acute fulminant invasive fungal sinusitis
- Chronic invasive fungal sinusitis
- Granulomatous invasive fungal sinusitis
6
Q
Describe a sinus fungal ball (mycetoma)
A
- Sequestration of fungal elements within a sinus without invasion or granulomatous changes
- Inhaled spores grow while evading host immune system (no invasion)
- Aspergillus most common species
- Maxillary sinus most often involved (70-80% of cases)’
- Presents similar to rhinosinusitis with congestion, facial pain, headache, rhinorrhea
7
Q
What are the CT scan findings of a fungal ball?
A
- Single sinus in 59-94% of cases (maxillary)
- Complete or subtotal opacification of sinus
- Radiodensities within the opacifications (due to increased heavy metal content)
- Bony sclerosis; destruction is rare (3.6-17% of cases)
- biopsy will show fungal elements
8
Q
What is the treatment of a fungal ball (mycetoma)?
A
- Complete surgical removal of fungal ball
- Irrigation of involved sinuses
- Antifungal therapy - only if patient is high risk for invasive disease (very rare)
- Consider topical antifungal irrigation first and then systemic therapy if no improvement
9
Q
Describe allergic fungal sinusitis
A
- Fungal colonization resulting in allergic inflammation without invasion
- IgE mediated response to fungal protein
Symptoms:
Nasal obstruction (gradual)
Rhinorrhea
Facial pressure/pain
Sneezing, watery/itchy eyes
Periorbital edema
10
Q
What are the diagnostic criteria for allergic fungal sinusitis?
A
Diagnostic Criteria
- Eosinophlic mucin - pathognemonic
- Nasal polyposis
- Radiographic findings
- Immunocompetance
- Allergy to fungi
Charcot-Leyden crystals
11
Q
What are the CT scan findings in allergic fungal sinusitis?
A
- Unilateral (78% of cases)
- Sinus expansion
- Bone destruction in 20% of cases (more often in advanced or bilateral disease)
- “Double Densities” - Heterogeneity of signal, increased heavy metal content (iron and manganese) and calcium salts
12
Q
What is the treatment of allergic fungal sinusitis?
A
Surgical
- Remove all mucin
- Provide permanent drainage and ventilation of affected sinuses
Systemic +/- topical steroids
- Systemic steroids decrease rate of recurrence
- Course can range from 2-12 months
- 0.5mg/kg Prednisone starting dose and taper over 2-3 months
Immunotherapy
- decrease recurrence
- alleviate need for steroids
13
Q
Describe acute fulminant invasive fungal sinusitis
A
Most often in immunocompromised (DM, AIDS, leukemia)
Most common fungi
- Aspergillus
- Mucormycosis (mucor, rhizopus, absidia)
Less common fungi
- Candida
- Bipolaris
- Fusarium
14
Q
Describe the pathogenesis acute fulminant invasive fungal sinusitis
A
- Spores are inhaled, fungus grows in warm and humid sinonasal cavity
- Fungi invade neural and vascular structurs with thrombosis of vessels
- Necrosis and loss of sensation leads to acidic environment, further growth
- Extrasinus extension occurs via bony destruction, PNI, PVI
15
Q
What are some clinical findings in acute fulminant invasive fungal sinusitis?
A
- Destruction of palate
- Facial anesthesia
- Proptosis
- CN deficits
- MS changes
- Fevers (most common)
- Ulceration of face
- Rhinorrhea
- Headaches
- Seizures
- Pale to black mucosa on endoscopy
- Death in hours to days!
16
Q
What are the CT scan findings in acute fulminant invasive fungal sinusitis?
A
- Bone erosion and extrasinus extension – classic finding
- Severe, unilateral mucosal thickening
- Thickening of periantral fat planes
- Can involve cavernous sinsus
17
Q
What is the treatment of acute fulminant invasive fungal sinusitis?
A
Medical
- Correct the underlying compromised state
- Reverse DKA and improve hydration
- 80% survival if done promptly
- Absolute neutrophil count (< 1000 = poor prognosis)
- WBC transfusion and granulocyte colony stimulating factor to increase ANC
- Amphotericin B (ototoxic, nephrotoxic)
- Voriconazole or itraconazole (Mucor is resistant to these)
Surgical
- Endoscopic in early course of disease
- Open in advanced disease
- Debride until bleeding margins
- Once intracranial, very high mortality
- Overall mortality 18-80%
- Mucromycosis = most fatal
18
Q
Describe chronic invasive fungal sinusitis
A
- Slower disease process than acute
- Rare
- Biggest difference - Most patients are immunocompetent
Common fungi
- Aspergillus (most common at 80% of cases)
- Bipolaris
- Candida
- Mucormycosis
19
Q
What are some clinical findings in chronic invasive fungal sinusitis?
A
- Similar to CRS
- Nasal congestion
- Rhinorrhea
- Facial pressure
- Headaches
- Polyposis
- Proptosis, visual changes, numbness, epistaxis all more concerning
- Does not respond to antibiotics
- Worsens with steroids
- CT same as AFIFS
- Few if any inflammatory cells (major diff between acute and chronic invasive disease)
20
Q
What is the treatment of chronic invasive fungal sinusitis?
A
Medical
- Similar to AFIFS
- Start with amphotericin B until r/u Mucor
- Topical ampho B sinus rinse
Surgical
- Debride until bleeding margins
- Biopsy any suspicious lesions
21
Q
Describe granulomatous invasive fungal sinusitis
A
- Appears exactly like CIFS
- Very rare
- Presence of multinucleated giant cell granulomas (Most important difference between Chronic and Granulomatous disease)
- Aspergillus flavus
- Most often seen in North Africa and Southeast Asia
- Presentation and workup are the same as CIFS
22
Q
What is the treatment of granulomatous invasive fungal sinusitis?
A
Medical
- Topical antifungal rinses
- Oral voriconazole or itraconazole
Surgical
- Debridement until bleeding margins
- Biopsy anything that is suspicious
23
Q
Features of Frontal Sinus
A
- Does not appear until 5–6 years old
- Drainage: frontal recess in anterior middle meatus either medial or lateral to the uncinate (posterior and medial to agar nasi cells), may also be lateral to agar nasi cells
- Vasculature: supraorbital and supratrochlear arteries, ophthalmic (cavernous sinus) and supraorbital (anterior facial) veins
- Innervation: supraorbital and supratrochlear nerves (V1)
- Plain Film: lateral and Caldwell view
- Foramina of Breschet: small venules that drain the sinus mucosa into the dural veins
24
Q
Features of Maxillary Sinus
A
- First to develop in utero, biphasic growth at 3 and 7–18 years old
- Drainage: ethmoid infundibulum (middle meatus, 10–30% have accessory ostium)
- Vasculature: maxillary and facial artery, maxillary vein
- Innervation: infraorbital nerve (V2)
- Plain Film: Water’s view
25
Features of Ethmoid Sinus
* 3–4 cells at birth (**most developed paranasal sinus at birth**), formed from 5 ethmoid turbinals (1. agar nasi, 2. uncinate, 3. ethmoid bulla, 4. ground lamella, 5. posterior wall of the most posterior ethmoid cell)
* Drainage: anterior cells drain into the ethmoid infundibulum, posterior cells drain into the spheno-ethmoid recess (superior meatus)
* Vasculature: anterior and posterior ethmoid arteries (from ophthalmic artery), maxillary and ethmoid veins (cavernous sinus)
* Innervation: anterior and posterior ethmoidal nerves (from nasociliary nerve, V1)
* Plain Film: lateral and Caldwell view
26
Name the 5 ethmoid turbinals
1. agar nasi/uncinate
2. middle turbinate
3. superior turbinate
4. supreme turbinate
27
What is the most developed paranasal sinus _at birth?_
**Ethmoid sinus** (maxillary is first to develop in utero)
28
What is an Agger Nasi Cell?
Most **anterior** of anterior ethmoid cells
29
What is the Ground (Basal) Lamella?
Posterior bony insertion of the middle
turbinate which separates anterior and posterior ethmoid cells; posterior extension of the middle turbinate
30
What are Onodi Cells?
ethmoid cells that pneumatize lateral or posterior to
anterior wall of the sphenoid, commonly mistaken as a sphenoid cell, optic nerve may indent into the lateral wall
31
What are Haller Cells?
ethmoid cells that extend into maxillary sinus above
the ostium, pneumatize the medial and inferior orbital walls
32
What is the Lamina Papyracea?
lateral thin bony wall of the ethmoid sinus,
separates orbit from ethmoid cells as a part of the medial orbital wall
33
What is the Fovea Ethmoidalis?
roof of the ethmoid sinus
common site of CSF leak
34
Features of Sphenoid Sinus
* Evagination of nasal mucosa into sphenoid bone
* Drainage: sphenoethmoid recess in the superior meatus
* Vasculature: sphenopalatine artery (from maxillary artery), maxillar vein (pterygoid plexus)
* Innervation: sphenopalatine nerve (parasympathetic fibers and V2)
* Plain Film: lateral and submentovertex (basal)
* Adjacent Structures: pons, pituitary (sella turcica), carotid artery (lateral wall), optic nerve (lateral wall), cavernous sinus (laterally), maxillary and abducens nerves, clivus
35
List the nasal cartilages
* Upper Lateral Cartilage
* Lower Lateral (Alar) Cartilage: paired cartilage, composed of lateral and medial crura
* Sesamoid Cartilage
* Lesser Alar Cartilage
36
Describe the septal anatomy
* **Quadrangular Cartilage**: septal cartilage
* **Perpendicular Plate of the Ethmoid:** projects from cribiform plate to septal cartilage
* **Vomer:** posterior and inferior to perpendicular plate
* **Maxillary Crest** (Palatine Bone): trough of bone that supports the septal cartilage
* **Anterior Nasal Spine:** bony projection anterior to pyriform aperture
37
What is a Tornwaldt cyst?
* A Tornwaldt cyst is a benign cyst located in the upper posterior nasopharynx.
* Forms as a result of retraction of the notochord where it contacts with the endoderm of the primitive pharynx.
* Initially is forms a small diverticula. Eventually inflammation results in obliteration of the mouth, resulting in a cyst.
* The cyst is lined by respiratory epithelium and accumulates with fluid with variable proteinaceous content.
* It was first described by Tornwaldt Gustav Ludwig.
38
What are the internal maxillary artery branches of the nose?
* descending palatine artery ➝ greater palatine and lesser palatine arteries
* sphenopalatine artery ➝ sphenopalatine foramen (posterior to the middle turbinate) ➝ medial (nasoseptal) and lateral nasal artery (middle and inferior turbinates)
39
What are the facial artery branches of the nose?
* superior labial artery ➝ nasal septum and alar branches
* lateral nasal artery
* angular artery
40
What are the internal carotid artery branches (ophthalmic artery) to the nose?
* anterior ethmoid artery (larger than the posterior ethmoid artery) ➝ lateral nasal wall and septum
* posterior ethmoidal artery ➝ superior concha and septum
* dorsal nasal artery ➝ external nose
41
What are the functions of the paranasal sinuses?
1. Resonating chambers for the voice
2. Protection of the brain in trauma
3. Moisturize and humidfy air
4. Lightening the weight of the human skeleton
42
What is the Keros Classification?
**classifying the depth of the olfactory fossa **
The ethmoid labyrinth is covered by the fovea ethmoidalis of the frontal bone and separates the ethmoidal cells from the anterior cranial fossa.
The very thin, horizontal cribriform plate (lamina cribrosa) of the ethmoid bone is bounded laterally by the vertical lateral lamella. The lateral lamella joins the cribriform plate to the fovea ethmoidalis.
The depth of the olfactory fossa is determined by the height of the lateral lamella of the cribriform plate
Type 1 : has a depth of **1 - 3 mm** (26.3% of population)
Type 2 : has a depth of **4 - 7mm ** (73.3% of population)
Type 3 : has a depth of **8 - 16mm** (0.5% of population)
43
The most common sites of erosion or defects in the skull base are?
1. cribriform plate (51%)
2. sphenoid lateral pterygoid recess (31%)
3. ethmoid roof (8%)
4. perisella
5. inferolateral or pterygoid recesses
44
What is the Keros Classification?
* Type 1 : has a depth of 1 - 3 mm (26.3% of population)
* Type 2 : has a depth of 4 - 7mm (73.3% of population)
* Type 3 : has a depth of 8 - 16mm (0.5% of population)
45
What is an antrochoanal polyp?
benign lesions that arise from the mucosa of the maxillary sinus, grow into the maxillary sinus and reach the choana, and nasal obstruction being their main symptom.
46
What is the dosage used for intrathecal flourescein when diagnosing a CSF leak?
0.1mL of 10% IV flouresceine diluted in 10ml of CSF
47
List the measurements of the anterior and posterior ethmoidal arteries
The **anterior ethmoidal foramen** is located at a distance of **_24 mm_** from the **anterior lacrimal crest**
The **posterior ethmoidal foramen** is located at a distance of **_36mm_** from the **anterior lacrimal crest**, or **_12mm_** from anterior ethmoidal foramen
