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11 Cards in this Set
What is a Haller cells?
Ethmoidal air cell extending along the medial and inferior floor of the orbit. It tends to obstruct the maxillary sinus ostium or the
infundibulum, predisposing a patient to masinusitis sinusitis.
1. What is sinonasal polyposis?
2. What are the imaging findings of sinonasal polyposis?
1. Inflammatory swelling of sinonasal mucosa that buckles to form "polyps"
- Involves nasal cavity & paranasal sinuses
Aggressive sinus disease with bony destruction
INVASIVE FUNGAL SINUSITIS:
- MC in immunocmpromised pts (diabetics, chemotx)
- Fungal secretions are hyperdense on CT; calcifications are common.
- Hypointensity on MRI on both T1 and T2
- MC organisms = Mucormycosis and Asperigillosis
- Mucormycosis = spreads to the cavernous sinus and orbits
- Aspergillus = invades vasculature resulting in mycotic aneurysms and vessel spasm or thromboses.
- vascultis that affects the kidneys and respiratory tract.
- recurrent sinonasal "infections"
- Early = nasal septal erosion
- Later = formation of sinus mass with extensive bony erosion. Soft tissue mass is hypointense on both T1 and T2WI and ENHANCES.
- SCC accounts for ~90% of sinus malignancies.
- Maxillary sinus > ethmoid sinus
- Involvement of pterygopalatine fossa allows for communication with the orbit and middle cranial fossa resulting in perineural spread of tumor.
- looks like SCC of the sinus.
- look for significant LAD within neck and involvement of Waldeyer tonsillar ring (adenoids, palatine, and lingual tonsils)
- granulomaous response resulting in a soft tissue mass and cartilaginaous erosion.
- Granulomatous response + vasoconstriction results in necrosis of the nasal septum with bony and cartilaginous destruction.
1. Provide a differential diagnosis for a unilateral polypoid mass in the paranasal sinus.
2. Bilateral polypoid masses in the sinuses would include what diagnoses?
- Inverted papilloma
- antrochoanal polyp
- allergic polyposis
- allergic fungal sinusitis
- juvenile angiofibroma
- fungus ball(mycetoma)
- mucous retention cyst
- Allergic or inflammatory polyposis
- cystic fibrosis
- fungus balls
1. What is the etiology of antrochoanal polyps?
2. What are the imaging findings?
- obstruction of the ostiomeatal complex.
- less likely, response to allergens
- Bright on T2W scans with peripheral gadolinium enhancement (not central - distinguishes from malignancy)
- Well-defined dumb-bell shaped mass located in the maxillary antrum extending into the nasal choana.
- Most common in teenagers & young adults
- No malignant potential.
1. What is the etiology of papillomas?
2. What are the three different types of papillomas in the nose?
1. HPV infection
- inverted papillomas: arise from the lateral nasal wall. Associated with
- fungiform papillomas: arise from the nasal septum and are unilateral and solitary.
- cylindric cell papillomas: arise from the lateral nasal wall.
Aggressive nasal mass in an adolescent
- benign locally aggressive lesions seen in adolescent males.
- originate in the nasopharnyx adjacent to the sphenopalatine foramen and near the pterygopalatine fossa.
- from this location the mass may spread into multiple compartments including the intracranial, intraorbital, and infratemporal, and paranasal sinuses.
- Anterior bowing of the posterior maxillary sinus wall.
- Avid enhancent; flow voids are common.
- malignant neuroendocrine tumor that arises from the olfactory endothelium within the superior nasal cavity.
- intracranial extension through the cribriform plate is common.
- dumbbell-shaped mass in the nasal cavity/nasopharynx and anterior cranial fossa with a narrowed waist at the level of the cribriform plate.
- occur along the nasal septum or turbinates
- circumscribed, avidly enhancing nasal soft tissue mass.
- most common nasal sarcoma in adolescents. SCC and lymphoma are less common in children.
- benign locally aggressive neoplasms
- originate along the middle meatus and extend into the sinuses.
- heterogeneous enhancement
- may have calcifications
- T2WI demonstrate linear striations.
- Solitary polyps
- Sinonasal polyposis
- Antrochoanal polyps
- Most commonly arise from the maxillary sinus and extends into the nasal cavity and nasopharynx.
- demonstrate peripheral mucosal enhancement
1. What is the etiology of Juvenile nasopharyngeal angiofibroma?
2. What does sphenopalatine foramen connect?
3. What are the imaging findings?
1. Benign vascular tumor of the nasopharynx thought to arise from malformation of vasculature in and around the sphenopalatine foramen.
- found exclusively in males 10-20 years old.
2. The sphenopalatine foramen is a foramen in the skull that connects the nasal cavity with the pterygopalatine fossa.
- Heterogeneous mass in the nasopharynx adjacent to the pterygopalatine fossa.
- Anterior bowing, thinning, and erosion of the posterior wall of the maxillary antrum without destruction.
- May extend into the intracranial cavity via the foremen rotundum or inferior orbital fissure.
- devrives blood supply from the internal maxillary artery. When doing the embolization make sure that the ophthlamic artery does not arise from the internal maxillary artery as this may result in blindness.
- embolize both sides
If anterior = pyriform aperture stenosis
- single megaincisor
- cleavage abnormality in the brain (holoprosencephaly)
If posterior = choanal atresia
- associated with CHARGE syndrome
- typically located along the lateral nasal wall
- centered at middle meatus with extension into the maxillary antrum
- Focal hyperostosis of adjacent bone may indicate point of tumor attachment.
- Hyperintense to skeletal muscle on T2WI with curvilinear striations or "convoluted, cerebriform pattern"
- **If portion of tumor appears invasive or necrosis present → consider synchronous SCCa
- MR helpful in differentiating tumor from obstructed secretions.
- High recurrence rate & propensity for metachronous associated SCCa makes radiologic follow-up imperative
Mass in the superior nasal cavity
- Not a glioma; represents dysplastic brain tissue that is sequestered from the brain and meninges.
- **no connection to the brain or meninges and not surrounded by CSF (differentiates from cephalocele)
- may or may not enhance
- May be intranasal or extranasal (presents as a mass on the dorsum of the nose).
- Congenital herniation of meninges, CSF ± brain tissue through defect in anterior skull/skull base
- connection to intracranial brain parenchyma
DERMAL SINUS TRACT:
- extends from the anterior skull base through the nasal septum toward the nasal tip where it presents as a pit.
- Associated dermal cyst can be seen anywhere along the tract of the dermal sinus.