Paranasal sinus neoplasms, both benign and malignant, are relatively rare in the head and neck. Malignant neoplasms of the paranasal sinuses account for approximately 3.0% of head and neck cancers and 0.5% of all malignant tumors. In general, these tumors are identified and treated at advanced stages as their symptoms mimic benign inflammatory conditions. The most common malignant neoplasm of the nose and paranasal sinuses is squamous cell carcinoma. This tumor most commonly arises from the maxillary antrum and secondarily from the ethmoid sinus. Treatment includes surgical resection, radiation therapy, and, rarely, chemotherapy. Benign tumors present in a similar manner and typically necessitate surgical resection and close postoperative follow-up. As nasal endoscopes are used with increasing frequency clinically, both benign and malignant tumors will ideally be identified earlier in the disease progression.
The most common presenting symptoms in patients with paranasal sinus neoplasms are nasal obstruction, rhinorrhea, and sinus congestion that are similar to those of patients with benign sinonasal diseases. However, as the masses grow, paranasal sinus neoplasms lead to facial pain and epistaxis. In addition, orbital symptoms, such as diplopia, proptosis, visual loss, and epiphora, can occur with either neoplastic invasion or expansion into the orbit. Entry through the skull base into the anterior cranial fossa can lead to the symptoms of headache, cranial neuropathies, and occasional frontal lobe symptoms (such as personality alterations). Tumors can also invade the maxilla and present as a hard-palate mass.
The physical examination of a patient suspected to have a paranasal neoplasm should include a complete head and neck examination, which includes diagnostic nasal endoscopy. While small tumors grow silently without symptoms, persistent nasal symptoms should be evaluated with nasal endoscopy.
The examination of the nose and paranasal sinus cavity can reveal a nasal mass with overlying polyps or polypoid mucosa. The septum can be markedly deviated to the contralateral side because of the expansion of the neoplasm, sometimes with tumor erosion into the contralateral nasal cavity. An endoscopic evaluation is superior at evaluating the mucosa, identifying masses and drainage.
The teeth and hard palate need to be examined closely to determine if invasion into the maxilla has occurred. An expanded alveolar ridge or loose maxillary dentition indicates early bony invasion of the maxilla, and a mass on the hard palate indicates frank invasion into the maxilla.
Facial swelling and thickening of the cheek and nose skin is an indication that the neoplasm has invaded the soft tissue through the anterior bony walls. Proptosis is seen with expansion through the lamina papyracea compressing the periorbital benign disease, such as mucocele, and in malignant disease due to intraorbital invasion. Diplopia is commonly seen with proptosis, and visual loss is a sign of progressive orbital involvement; however, visual loss also can be a sign of orbital apex involvement with compression of the optic nerve.
Cranial nerve (CN) involvement is common in advanced malignant neoplasms of the paranasal sinuses. The olfactory nerve, CN I, is involved in esthesioneuroblastomas. Other CNs involved are the optic nerve (CN II), the oculomotor nerve (CN III), the trochlear nerve (CN IV), the abducens nerve (CN VI), and supraorbital and maxillary branches of the trigeminal nerve (CN V1 and CN V2).
Other findings that can be identified by the physical examination are serous otitis media due to eustachian tube involvement, and neck masses due to metastatic neoplastic spread into the regional lymph nodes. The most commonly involved lymph nodes are the upper jugulodigastric nodes.
Imaging is critical to identify the extent of both benign and malignant diseases. A computed tomography (CT) scan can delineate the mass well and can be sufficient for both bony and benign diseases. It is excellent for determining bony invasion but limited for distinguishing between edematous mucosa and tumor involvement and in identifying the intracranial extension of tumors. Magnetic resonance imaging (MRI) with both T1- and T2-weighted images with gadolinium enhancement is superior in determining the true involvement of the anterior cranial fossa, the skull base, and the orbit (Figure 17–1). MRI is also superior at soft-tissue delineation, can distinguish a tumor from obstructed secretions in the sinus, and complements the bony architecture information obtained from the CT scan. Both scans are often needed to ensure appropriate surgical planning.
Axial T2-weighted MRI scan showing a mass in the right ethmoid sinus.
A biopsy of the mass is critical both in diagnosing a malignant tumor and in determining its treatment. If the mass is easily visualized in the physician's office, then an in-office biopsy should be obtained of the mass itself and not just the overlying tissue. Considerations for this biopsy include the assurance that the lesion is not vascular or does not contain cerebrospinal fluid (CSF). These lesions are often soft, cystic, and expand with a Valsalva maneuver. A needle biopsy of these lesions can be considered if the diagnosis is still uncertain.
The differential diagnosis of a paranasal sinus mass is extensive (Table 17–1). The most common benign lesion of the paranasal sinuses is the inverted papilloma. The most common malignant neoplasm of the paranasal sinuses is squamous cell carcinoma. Additional tumors that are frequently seen are adenocarcinoma, adenoid cystic carcinoma, olfactory esthesioneuroblastoma, malignant mucosal melanoma, and sinonasal undifferentiated carcinoma.
Table 17–1. Differential Diagnosis of Nasal and Paranasal Sinus Masses. |Favorite Table|Download (.pdf)
Table 17–1. Differential Diagnosis of Nasal and Paranasal Sinus Masses.
|Benign Masses||Malignant Masses|
|Chondroma||Adenoid cystic carcinoma|
|Juvenile angiofibroma||Malignant mucosal melanoma|
|Ossifying fibroma||Sinonasal undifferentiated carcinoma|
|Osteoma||Squamous cell carcinoma|
|Schwannoma||Teratoma or teratocarcinoma|