Sinonasal lesions and masses Flashcards
List a broad differential for septal perforation
INFECTIOUS
1. Tuberculosis
2. Leprosy
3. Syphillis
4. Septal abscess
INFLAMMATORY
1. GPA
2. Sarcoidosis
3. SLE
4. Drug induced vasculitis
VASCULAR
1. Poorly controlled diabetes
2. Peripheral Vascular Disease
TRAUMA/IATROGENIC
1. Nasal trauma
2. Post septoplasty
3. Septal hematoma
4. Chronic nose-picking
5. Post nasal cautery
DRUGS
1. Chronic nasal decongestant use
2. Cocaine
NEOPLASTIC
1. Lymphoma
What is the difference between a mucous retention cyst vs. a mucocele of the sinus?
What is the cause of each?
Where are each most commonly found?
Mucous Retention Cyst (Pseudocyst):
- Retained mucous within a blocked goblet cell, lined by sinus mucosa rather than true epithelium - Mucous filled sac along a mucosal lining - PSEUDOCYST
- Secondary to obstruction of a mucous gland
- Common (10% of the population) usually asymptomatic
- Maxillary sinus MOST common
- Treatment not required unless obstructive
Mucocele (True cyst) :
- A TRUE cyst - chronic, cystic lesion of the paranasal sinuses lined with pseudostratified or low columnar epithelium, containing occasional goblet cells
- EXPANDING mucous containing epithelial lined cyst
- Due to obstruction of the sinus ostium causing obstructed drainage
- Results in secretion entrapment, bone resorption, and can be locally destructive
- Mucopyocele = infected mucocele
- Frontal (65%) > Ethmoid (25%) > Maxillary (10%) > Sphenoid (1%) - FEMS
- Radiologically presents with complete sinus opacifications, with rounded thinning pushing margins; blocked sinus
- Treated with FESS
DIFFERENT THAN MUCOUS RETENTION CYST/MUCOCELE OF SALIVARY GLAND
Kevan Page 29-30
What are the CT and MRI findings for Mucocele
- Hypointense on CT
- MRI Variable pattern, depends on hydration
1. Hyperintense on T1 (when dehydrated)
2. Hyperintense secretions on T2 with hypointense central area
3. T1 + Gad: Generally does NOT enhance, but if enhancing will do so at periphery
What is the most common sinonasal tumor?
Osteoma
What is the most common sinonasal tumor requiring intervention?
- Inverted papilloma (which is the second most common sinonasal tumor overall)
Discuss the differential for benign sinonasal tumors
A. EPITHELIAL TUMORS
1. Schneiderian Papillomas:
a/ Inverted
b/ Exophytic
c/ Oncocytic
2. Salivary gland adenoma
B. SOFT TISSUE TUMORS
1. Leiomyoma
2. Hemangioma
3. Schwannoma
4. Neurofibroma
C. BONE/CARTILAGE TUMORS
1. Chondroma
2. Osteoma
3. Chondroblastoma
4. Osteochondroma
5. Osteoid Osteoma
6. Osteoblastoma
7. Chondromyxoid fibroma
8. Sinonasal ameloblastoma
9. Chondromesenchymal hamartoma
10. Desmoplastic fibroma
Differential diagnosis for midline benign lesions 7
- Squamous papilloma
- Pleomorphic adenoma
- Hemangioma
- Angiofibroma
- Fibrous dysplasia
- Chondroma
- Osteoma
What are the 4 most common benign bony lesions/fibroosseous lesions of the sinonasal cavity?
- Osteoma
- Fibrous dysplasia
- Ossifying fibroma
- Osteochondroma
What are the 4 most common benign tumors of the sinonasal tract, in order of frequency?
- Osteoma
- Hemangioma
- Inverted papilloma/Papilloma
- Angiofibroma (JNA)
You see a unilateral mass in the nasal cavity. What should you NOT do?
- DO NOT BIOPSY
- May be an encephalocele or JNA
- Always image prior to biopsy
Regarding Antrochoanal polyp, discuss:
1. What is it?
2. Pathophysiology?
3. Features?
4. Treatment
ANTROCHOANAL POLYP:
- Inflammatory polyps (non-eosinophilic) arising from the mucosa of the maxillary sinus and extending through posterior accessory os to the nasal cavity or nasopharynx
Pathophysiology:
- Unclear
- Some suggest that these results from obstruction of natural os causing the polyp to enlarge and herniate through the posterior accessory os
Features:
- Almost always unilateral
- 4-6% of all polyps in general population
- 33% of all polyps in a pediatric population
Treatment:
- Endoscopic removal
Regarding sinonasal papillomas, discuss:
1. What are the risk factors 5
2. Clinical presentation?
3. What is the classification?
3. What is the staging?
4. Investigations?
4. What are the histopathologic findings?
5. What are the radiographic findings?
6. What are the treatment options?
Sinonasal papilloma
- Previously called Schneiderian papillomas
- Proliferation of squamous epithelium through finger-like projections into underlying stroma
RISK FACTORS:
1. M > F, Caucasian
2. Usually occurs around 5th to 7th decade of life
3. Organic solvents (carbon-based substances capable of dissolving or dispersing one or more other substances)
4. Smoking increases risk of recurrence and malignant transformation
5. HPV 6 & 11
6. EBV suspected (inhibit p53)
CLINICAL PRESENTATION:
1. Nasal obstruction (87%)
2. Rhinorrhea
3. Facial pain/pressure
4. Epistaxis
5. Frontal headaches
6. Epiphora
7. Exophytic, fleshy, sessile vs. pedunculated
8. Bony destruction/erosion common
9. Tendency to recur
CLASSIFICATION
1. Inverted Papilloma
- Most common - 50%
- 10% risk of malignant transformation
- Most commonly arises from the lateral nasal wall
- Recurrence rate 27-73%
- Exophytic Papilloma (aka. Fungiform)
- Second most common - 47% frequency
- 5% risk of malignant transformation
- Associated with HPV 6,11
- Most commonly arises from the septum
- Recurrence rate 22-50% - Oncocytic Papilloma (aka. Cylindrical)
- Third most common - 3%
- 15% risk of malignant transformation
- Most commonly arises from the lateral nasal wall (like IP)
- Recurrence rate 25-35%
INVESTIGATIONS:
1. Scope
2. CT: Look for osteitis sign (likely attachment/origin point)
3. MRI
4. Biopsy
KROUSE STAGING SYSTEM
1. T1: Confined to the nasal cavity without extension to the paranasal sinuses
2. T2: Extends to the medial maxillary wall, ethmoid sinuses, or osteometal complex
3. T3: Extends to any other wall of the maxillary sinus (superior, lateral, anterior, medial, inferior wall of the maxillary sinus), frontal sinus, or sphenoid sinus
4. T4: Extension beyond the paranasal sinuses, OR if final pathology is malignant (malignant transformation)
HISTOPATHOLOGIC FINDINGS:
- Hyperplastic ribbons of basement membrane enclosed with epithelium that grows downwards into the underlying stroma
- May have squamous metaplasia
- Exophytic - exophytic fronds with fibrovascular core
RADIOGRAPHIC FINDINGS
- MRI: Convoluted cerebriform pattern (“brain like” alternating roughly parallel lines of high and low signal intensity); Iso/Hypo T1; Enhance with Gad; Hypertense on T2
- Bony hyperostosis (enlargment) at the site of attachment on CT (“osteitis sign”)
TREAMTMENT:
1. Endoscopic Sinus Surgery for Total surgical removal
- Medial Maxillectomy (endoscopic Denker’s)
- TuNa-saving technique (modified medial maxillectomy that spares the inferior TUrbinate (tu) and the NAsolacrimal duct (na)
- Open en-bloc resection (e.g. lateral rhinotomy)
Kevan Page 39
Vancouver 428
Regarding inverted papillomas, discuss in greater detail:
1. Epidemiology
2. Common locations
3. Histology
4. Rate of malignant transformation & risk factors
5. Molecular characteristics
6. Treatment
7. Prognosis
INVERTED PAPILLOMA:
1. Second most frequent benign tumor of sinonasal tract after osteoma
2. Most common type of sinonasal papilloma
Epidemiology:
- 5-6th decade of life
Locations:
1. Most common: Lateral nasal wall
2. Maxillary sinus (maxillary medial wall
3. 30% involve multiple
4. Uncommon: Frontal/sphenoid
Histology:
1. Hyperplastic ribbons of basement membrane-enclosed epithelium that grow downward into underlying stroma
Malignant Transformation: 5-15%
- Usually SCC
- Rarely SNUC, Mucoep, Verrucous carcinoma
- Risk factors: Exposure to organic solvent (dose-response relationship)
- No association with smoke/alcohol
Molecular:
1. Characterized by EGFR mutation
Treatment: Endoscopic resection (dissect subperiosteal plane and drill underlying bone), but may be contraindicated it:
1. Concomitant presence of malignancy involving critical areas
2. Site of origin on anterior wall or lateral recess frontal sinus
3. Orbital involvement
Prognosis:
1. Post-op surveillance is clinical
2. Risk for recurrence: incomplete or inadequate resection, high staging, recurrent tumor, smoking
Regarding exophytic papilloma, discuss:
1. Epidemiology
2. Risk factors
3. Location
4. Treatment
Epidemiology:
- Second most frequent sinonasal papilloma
Risk factors:
1. HPV (6 and 11 - low risk) - therefore rare malignant transformation
Location:
- Predominantly anterior, inferior nasal septum
Treatment:
1. Surgical resection with wide margin - Subperichondrial/subperiosteal dissection
Regarding oncocytic papilloma, discuss:
1. Epidemiology
2. Location
3. Histology
4. Molecular
5. Malignant transformation
6. Treatment
Epidemiology:
1. Rarest form of papilloma
Location:
1. Lateral nasal wall
2. Maxillary sinus
Histology:
1. Abundant mitochondria in cytoplasm
2. Inverted and exophytic growth
Molecular: KRAS mutation (O-K)
Malignant transformation:
1. 4-17% (similar to IP)
2. No risk factors associated
Clinical and radiologic appearance, treatment follow up - same as IP
List a complete differential for an expansile/eroding sinonasal lesion.
NON-NEOPLASTIC
1. Invasive fungal sinusitis (CIFS, AIFS)
2. Allergic fungal sinusitis
3. Mucocele
4. Sarcoidosis
5. GPA
6. Cocaine
NEOPLASTIC - BENIGN
1. Inverted papilloma
2. Exophytic papilloma
3. Oncocytic papilloma
4. Juvenile Nasal Angiofibroma
5. Hemangioma
6. Hemangiopericytoma
7. Ossifying fibroma
NEOPLASTIC - MALIGNANT
1. Squamous cell carcinoma
2. Adenocarcinoma
3. Small round blue cell tumors (MR-SLEEP)
Small round blue cell tumors (MMR-SSLEEPPI):
1. Melanoma
2. Merkel Cell Carcinoma
3. Rhabdomyosarcoma
4. SNUC
5. Small cell neuroendocrine tumor
5. Lymphoma (e.g. NK)
6. Esthesioneuroblastoma
7. Ewing’s sarcoma / PNET
8. Primitive neuroectodermal tumor
9. Plasmacytoma
10. + Immature Teratoma
Child most common: Rhabdo, esthesio, Ewing, Lymphoma
Differential diagnosis for midline destructive or midline necrotizing lesions - 10
- GPA
- Idiopathic midline destructive disease
- Polyarteritis nodosa
- Foreign body granuloma
- Lymphoma
- Midline lethal granuloma (NK T-cell lymphoma)
- Cocaine Use (may also show palate necrosis)
- Iatrogenic (nose picking, septal cautery, etc.)
- Septal abscess
- Post op status
Regarding JNA, discuss:
1. What does it stand for?
2. What is the epidemiology? 3
3. Location? 1
3. What are the proposed theories of etiology? 5
4. What are the common symptoms? 11
5. How is it usually diagnosed?
6. Besides imaging, what other investigations should be done?
6. What are the classic findings on imaging?
7. What are the classic findings on histopathology?
JNA = Juvenile Nasal Angiofibroma
EPIDEMIOLOGY:
1. Adolescent boys (males, second decade, rare beyond 25yo)
2. Caucasian
3. May be associated with FAP (Familial adenomatous polyposis, e.g. Gardner Syndrome)
LOCATION:
- Centered at the PPF (superior border of the sphenopalatine foramen-basisphenoid)
- Usually extends into nasopharynx ± pterygomaxillary fissure (PMF), infratemporal fossa (ITF), skull base, or cavernous sinus and orbit
CAUSATIVE THEORIES:
1. Hormonal
2. Embryologic remnant of the first arch artery
3. Non-chromaffin paraganglionic cells (variant of paraganglioma or infantile hemangioma)
4. Arises from embryologic fibrocartilage between the basi-occiput and basi-sphenoid; OR periosteum of skull base
5. Genetic (deltion of chromosome 17)
SYMPTOMS:
1. Unilateral nasal obstruction
2. Recurrent epistaxis
3. Serous otitis media / CHL
4. Proptosis (exophthalmos)
5. Obstructive sleep apnea
6. Dacrocystitis
7. Rhinolalia (nasal tone in speech especially when caused by excessive closure or openness of the posterior nares)
8. Hard and soft palate deformity
9. Facial swelling
10. Cranial neuropathy
11. Massive hemorrhage
DIAGNOSIS
1. Do NOT biopsy
2. FNL will show a large friable mass
3. Diagnosis is by clinical picture and imaging
IMAGING FINDINGS:
1. Arises from pterygopalatine fossa
2. Holman-Miller sign: Anterior bowing of the posterior wall of the maxillary sinus due to a space occupying lesion in the PPF
- Can also spread through openings of the PPF
3. Hyper intense on T2. Enhances on T1. Flow voids
OTHER INVESTIGATIONS:
1. Angio with embolization prior to removal
2. Female: Karyotyping to rule out androgen insensitivity/testicular feminization
PATHOLOGY FINDINGS:
1. Multiple thin walled vessels lackign smooth muscle in a fibrous connective tissue stroma with abundant mast cells
2. Benign fibrovascular lesion composed of 2 components:
a/ Fibrous component = fibrous or collagenous stroma with fibroblasts and spindle/stellate cells (arising from myofibroblasts)
b/ Vascular space = network of irregularly shaped blood vessels (no muscular layer)
2. Stains positive for Vimentin on electron microscopy
Kevan Page 40
What is the staging system(s) for Juvenile Nasal Angiofibroma?
One to memorize: UFMC (staged after pre-operative embolization)
I - nasal cavity, medial PPF
II - Paranasal sinuses, lateral PPF, no residual vascularity
III - skull base erosion, orbit, ITF, no residual vascularity
IV - skull base erosion, orbit, ITF, residual vascularity
V - intracranial extension, residual vascularity, M = medial extension, L = lateral extension
Multiple staging systems - Radkowski classification is the most commonly used
RADKOWSKI CLASSIFICATION
STAGE 1: Nasal cavity/Sinuses
- 1A: limited to nasal cavity ± nasopharynx vault
- 1B: Involvement of at least 1 paranasal sinus
STAGE 2: PPF/ITF
- 2A: Minimal lateral extension into the PPF
- 2B: Full occupation of the PPF with or without erosion of orbital bones
- 2C: Extension into the ITF laterally with or without cheek, OR extension posteriorly through the pterygoid plates
STAGE 3: Skull base/intracranial
- 3A: Erosion of base of skull ± minimal intracranial extension
- 3B: Extensive intracranial extension ± cavernous sinus involvement
CHANDLER CLASSIFICATION
1. Stage 1: Confined to nasopharynx
2. Stage 2: Extends to nasal cavity ± sphenoid
3. Stage 3: Extends to maxillary sinus, ethmoid sinus, PPF, ITF, orbit, or cheek
4. Stage 4: Intracranial extension
SESSIONS 1981 CLASSIFICATION
1. Stage IA: Tumor limited to posterior nares and/or nasopharyngeal vault
2. Stage IB: Tumor involving posterior nares and/or nasopharyngeal vault with involvement of at least 1 paranasal sinus
3. Stage IIA: Minimal lateral extension into Pterygomaxillary fossa
4. Stage IIB: Full occupation of pterygomaxillary fossa with or without superior erosion of orbital bones
5. Stage IIC: ITF with or without cheek invasion
6. Stage III: Intracranial extension
FISCH CLASSIFICATION
1. I: Limited to nose and/or nasopharyngeal vault
2. II: Extension to one or more sinuses, or the PPF
3. III: Invades the ITF, orbit, or parasellar areas
4. IV: Extends into cavernous sinus, optic chiasm, or pituitary fossa
What are 8 routes of intracranial spread for JNA?
- Direct extension through foramen rotundum, ovale, spinosum, and lacerum
- Through the pterygomaxillary fissure to the infratemporal fossa to the middle cranial fossa
- From the pterygomaxillary fissure to the inferior orbital fissure to the orbital cavity to the superior orbital fissure (to the middle cranial fossa)
- Through the cribriform plate to the anterior cranial fossa
- Through the roof of the sphenoid sinus into the sella (medial to IC and cavernous sinus)
- From the nasopharynx and nasal cavity along the vidian nerve into the floor of the sphenoid sinus
- Anteriorly: Posterior wall of the maxillary sinus is progressively pushed forward
- Through the ethmoid sinuses superiorly to the anterior cranial fossa
What are the treatment options for JNA? 4
- Pre-operative embolization (24-72h prior to excision) - significantly decreases intraoperative blood loss and facilitated resection of larger tumors
- Surgery is the mainstay of therapy - recurrence 30-50% (but can spontaneously regress in some cases)
- XRT 30-35Gy is reserved for recurrence or larger/unresectable lesions with significant risks in a developing child
- Hormonal therapy: Flutamide (testosterone receptor blocker) or estrogen - decreases size and vascularity of tumor, but due to risks and variable response not used
What is the blood supply to a JNA?
External Carotid artery branches (in the majority of cases)
- Internal maxillary artery –> sphenopalatine branches
- Ascending pharyngeal branches
Internal Carotid artery branches (usually in larger tumors)
- Ophthalmic artery
- Ethmoid arteries
- Branches of the cavernous carotid (hypophseal and meningeal branches)
MAIN BLOOD SUPPLY:
1. Internal maxillary artery
2. Others: Ascending pharyngeal, vidian artery, unnamed branches from the internal carotid artery (Rare)
List the possible surgical approaches to a JNA, from least to most invasive
A. Last Invasive: Endoscopic Endonasal
B. Open Approaches
1. Anterior Intraoral
a/ With Degloving Approach
- ± LeFort 1 osteotomy
- Transantral approach
- Modified transantral approach with medial maxillectomy
- Maxillary/zygomatic removal then reinsertion (maxillary swing)
b/ Without Degloving Approach
- Transpalatal approaches
- Anterior Facial
- Weber-Ferguson approach
- Lateral Rhinotomy
- Medial maxillectomy - Lateral
- Fisch Type D trans-temporal approach
- Pre-auricular ITF approach
- Subcranial
