The bulk of the tumour is within the ethmoid sinuses extending inferiorly into the nasal cavity and superiorly into the intracranial cavity through the cribriform plates
What is the lesion like?
Enhancing soft-tissue tumor expanding the ethmoid sinuses and nasal cavity
What are the MRI signal characteristics?
Mixed signal intensity on T2, low signal on T1, and intense enhancement on post-contrast images
What is the differential diagnosis of paranasal sinus tumour?
* Olfactory neuroblastoma: involves the ethmoid sinuses and extends through the cribriform plate into the anterior cranial fossa. Usually, shows intense enhancement and may show calcifications. They are slow growing with sinus expansion
* Juvenile angiofibroma: benign locally aggressive vascular tumor that affects adolescents. It is usually lobulated and expands the sphenopalatine foramen. Intense enhancement on post-contrast images
* Sinonasal carcinoma: heterogeneously enhancing mass that erodes the bone and may extend into the orbits or intracranially
* Lymphoma: low T2 signal with intense contrast enhancement and usually expands the bone
* Extra-axial CP angle mass.
* Heterogenous low signal intensity on T2.
* Intense enhancement on post-contrast images with thickening and enhancement of the tentorium cerebelli.
* No intracanalicular extension. Differential diagnosis: Schwannoma, ependymoma, metastasis