Sinus Tumors

Abtin Tabaee, MD

introduction
Benign and malignant neoplasms of the nose and paranasal sinuses are rare lesions, accounting for less than 1% of all tumors and approximately 3-5% of tumors involving the head and neck region.  There is significant variety and complexity in these tumors largely based on the anatomic location, extent and histology of the lesion. The treatments for these lesions are individualized to each patient and may incorporate a multi-disciplinary approach including various combinations of surgery, radiation therapy and chemotherapy.

Clinical presentation and diagnosis
 The symptoms associated with nasal-sinus neoplasms are non-specific and often initially difficult to distinguish from other nasal issues including inflammatory conditions such as allergies and sinusitis. Common symptoms for both neoplasms and inflammatory conditions include nasal congestion, facial pain/pressure, runny nose, post-nasal drip. Certain patterns of symptoms may be considered more concerning for neoplasm including new symptoms at an older age, severe symptoms, symptoms localized to one side, and symptoms that are atypical for allergies/ sinusitis including bleeding from the nose, facial swelling, eye symptoms and numbness of the face. Evaluation of patients with persistent nasal symptoms is typically performed by an otolaryngologist and involves taking a complete medical history, performing an examination of the head and neck region including endoscopy of the nasal and sinus areas. If there is any concern for a neoplasm, imaging studies are performed including CT scan, MRI scan and in certain situations PET-CT scan. If a neoplasm is suspected, a biopsy is typically performed for histologic characterization of the lesion. This is important since there are a number of different types of sinus and nasal tumors, with differences in clinical behavior and treatment considerations.

Benign and malignant tumor types
A variety of types of benign and malignant tumors may occur in the nose and paranasal sinuses. The potential benign lesions include papilloma (including inverted and squamous), fibro-osseous lesions (including osteoma, fibrous dysplasia), vascular tumors (including juvenile nasopharyngeal angiofibroma), neurogenic tumors (including schwannoma, neurofibroma) and tumors of minor salivary gland origin. The World Health Organization has classified the malignancies in the nose and paranasal sinuses based on the type of tissue (epithelial, soft tissue, bone and cartilage, hematolymphoid and neuroectodermal) with more that 25 specific histologies listed. These lesions may include squamous cell carcinoma, adenocarcinoma, adenoid cystic carcinoma, mucoepidermoid carcinoma, melanoma, olfactory neuroblastoma (esthesioneuroblastoma), sarcoma, and lymphoma. Malignant lesions from other body sites may metastasize to nose and paranasal sinuses. Differentiating between these lesions is critical and typically requires a biopsy.

Treatment considerations
The treatment decisions for benign and malignant nasal and sinus lesions are highly complex and may involve evaluation by several medical specialties including otolaryngology, radiation oncology, and medical oncology. The treatment decisions are based on the overall health of the patient, the histology of the lesion and the location and extension of the lesion, not only with relation to the nose and paranasal sinuses, but also with regards to surrounding structures including the orbit, intracranial cavity, and soft tissue of the face. The presence of spread of the lesion into the associated lymph nodes or to other body sites (metastases) will also impact treatment considerations.
   
Surgery for nasal and sinus neoplasms
If surgery is contemplated, there are several different techniques currently available, largely defined by the way the tumor is visualized and removed. Historically, surgery has been done through a variety of incision on the face and scalp. This technique is associated with wide surgical exposures and may be preferred especially in patients with extensive tumors. Endoscopic surgery represents a more recent development and has been described for both benign and malignant lesions over the past two decades. Endoscopic surgery typically involves visualization of the tumor through the natural air spaces of the nostrils and nasal cavity with the use of an endoscope (See Figure: arrow points to turbinate; arrowhead points to septum; asterisk is tumor) and camera. The benefits of the endoscopic approaches include avoidance of facial incisions and in certain situations improved visualization of the lesion. Regardless of the surgical technique used, the goals of the surgery are to achieve a complete removal of the tumor with the inclusion of an additional margin of tissue clear of any tumor, to preserve the critical neurovascular structures, to maintain normal function of the nose, sinuses and any other involved structures, and to maintain a separation between the intracranial and sinonasal cavities. These surgeries are often complex and require a team approach with otolaryngology, neurosurgery and in some cases plastic-reconstructive surgery and ophthalmology. The surgical resection of sinus and nasal tumors can be conceptually divided into different phases. The first phase involves preoperative planning which involves extensive discussions amongst the patient and the different members of the surgical team, obtaining the appropriate diagnostic studies and detailed coordination of the surgical needs with the operating room team. The surgery itself commences with the approach and exposure of the tumor. This typically involves dissection of the nasal and sinus structures surrounding the tumor until adequate visualization is achieved. This may additionally involve dissection of structures related to the orbit, soft tissue of the face and intracranial cavity if the tumor extends to these areas. Following adequate exposure, the tumor and a margin of tissue free of tumor are systematically separated from the attachment points and excised. The last phase of the surgery is reconstruction of any functionally important defects. This may involve repair of the skull base, the separation of the intracranial and sinonasal cavities. The final aspect of the surgical procedure is the postoperative recovery process, a portion of which typically occurs in the hospital and a portion of which occurs as an outpatient. Additional treatment including radiation therapy and/or chemotherapy may be indicated in certain lesions. All patients require long term follow up which typically involves examinations in the office and, based on the lesion, imaging studies.