Chapter 32: Tumors of the Paranasal Sinuses

Paranasal and Anterior Skull Base Anatomy

• The paranasal sinuses develop from mesenchymal and ectodermal tissue.

• The sinuses define the spaces for tumor development and bony margins are barriers for spread to adjacent tissue.

• The numerous foramina in the ventral skull base host critical neurovascular structures and allow direct tumor spread.

Paranasal Sinus Neoplasm Epidemiology

• Paranasal neoplasms vary from benign congenital malformations to high-grade malignancies.

• Squamous cell cancer (SCC) is the most common malignancy occurring with a frequency of 1:200,000 per year in the United States.

• Paranasal malignancies comprise less than 1% of all cancers and 3% of cancers of the upper aerodigestive tract.

• 55% of cancers in the paranasal sinuses originate in the maxillary sinus, 35% in the nasal passage, and 10% in the ethmoids.

• Tumors of the frontal and sphenoid sinus account for less than 1% of paranasal malignancies.

History and Presentation

• Paranasal tumors are a diagnostic and therapeutic challenge because they initially mimic common inflammatory sinonasal disease leading to delayed diagnosis and higher stages at diagnosis.

• Most common symptom: nasal obstruction.

• Second most common symptom: neck lymphadenopathy.

• Nasal: discharge, congestion, epistaxis, disturbance of smell.

• Facial: infraorbital nerve hypoesthesia, pain.

• Ocular: unilateral epiphoria, diplopia, fullness of lids, pain, vision loss.

• Auditory: aural fullness, otalgia, hearing loss.

• Oral: pain involving the maxillary dentition.

• Constitutional symptoms: fever, malaise/fatigue, weight loss.

Associated Causative Factors

• Squamous cell carcinoma (SCC): nickel, aflatoxin, chromium, mustard gas, volatile hydrocarbons, and organic fibers that are found in the wood, shoe, and textile industries

• Adenocarcinoma: wood dust, woodworking, furniture making, leather work

• Human papilloma virus (HPV) may be a cofactor in some tumors; however, this finding may be an association and not a cause and effect situation.

  1. Tumor suppressor protein inhibition by viral E6 and E7 proteins has not been well studied in paranasal sinus tumors.

Physical Examination

• Head/face: midface/periorbital edema

• Eye: proptosis, visual field deficits, extraocular motion restriction, fullness of eyelids, chemosis, ptosis

• Ear: middle ear effusion (often unilateral)

• Nose: nasal cavity mass

• Oral cavity: loose dentition, palatal sensory asymmetry, trismus, malocclusion, erosion of mass into the oral cavity

• Neurologic: cranial nerve (CN) deficits, which commonly include CN I, II, III, IV, V1, V2, VI

Diagnostic Nasal Endoscopy

• Evaluate extent of tumor and attempt to determine the origin or base.

• Perform Valsalva maneuver under direct visualization—expansion implies intracranial or major venous extension.

• Evaluate for ease and safety of biopsy.

Diagnostic Biopsy