Sinonasal Tract Tumors

Boris Hristov and Gopal K. Bajaj

Background

What is the incidence of sinonasal tract (SNT) tumors in the U.S.?

~2,000 cases/yr of SNT tumors (<1% of all tumors)

Is there a gender predilection for SNT tumors?

Yes. Males are more commonly affected than females (2:1).

SNT tumors are more common in what continents?

SNT tumors are more prevalent in Asia and Africa.

What histologies are typically seen with SNT tumors?

Squamous (most common), melanoma, adenocarcinoma, adenocystic, esthesioneuroblastoma (ENB), sarcoma (rhabdomyosarcoma), lymphoma, plasmacytoma, and mets

What nonmalignant entities present as a mass in the paranasal sinuses (PNS) or the nasal cavity?

Sinonasal polyposis, choanal polyps, and juvenile angiofibromas all present as a mass in the SNT.

What sinuses make up the PNS?

The frontal, ethmoid, sphenoid, and maxillary sinuses make up the PNS.

What structures border the maxillary sinus?

Anterolateral: facial bone
Superior: orbital floor
Inferior: hard palate
Medial: nasal cavity
Posteromedial: infratemporal fossa

What is the name for the thin bone in the medial wall of the orbit that is prone to erosion/breakthrough by ethmoid tumors?

The thin bone of the medial orbital wall is called the lamina papyracea.

What is the local invasion pattern of ethmoid tumors?

Superiorly through the cribriform plate to the ant cranial fossa or medially through the lamina papyracea into the orbit

Which is the most common sinus/site of origin for SNT tumors?

The maxillary sinus is the most commonly involved sinus/site for SNT tumors (70%–80%).

What is the most common site for ENB?

The nasal cavity is the most common site for ENB.

What environmental exposures are associated with the development of SNT tumors?

Thorotrast, nickel, chromium, hydrocarbons, nitrogen mustard, and wood dust (500 times risk for maxillary sinus tumor)

Workup/Staging

What are some presenting Sx of SNT tumors?

Facial pain, epistaxis, sinus obstruction, trismus (pterygoid involvement), ocular deficits (diplopia, blurry vision), facial pain due to trigeminal neuralgia, midfacial hypesthesia from impingement of the infraorbital branch of CN V, palatal mass/erosion, and otalgia

What is the basic workup for SNT tumors?

SNT tumor workup: H&P, labs, CT/MRI head/neck, Bx, and CT C/A/P

Describe the T staging of maxillary tumors per the latest AJCC classification.

T1: confined to sinus, no bone erosion
T2: bone erosion without involvement of post wall of maxillary sinus or pterygoid plate
T3: invasion of post wall of max sinus, pterygoid fossa, floor/wall of orbit, ethmoid sinus
T4a: invasion of ant orbital structures, skin of cheek, pterygoid plate, infratemporal fossa, cribriform plate, sphenoid or frontal sinus
T4b: invasion of orbital apex, nasopharynx, clivus, intracranial extension, CN involvement (except V2)