This is a rare tumor originating from the olfactory epithelium and represents 3% of all intranasal neoplasms. It was originally described by Berger and Luc.⁵ This tumor has been identified under different terms, including olfactory neuroblastoma, esthesioneurocytoma, and olfactory esthesioneuroblastoma. It arises from cells of neural crest origin and resembles childhood neuroblastoma. The tumor does contain neurosecretory granules and is linked to other neural crest tumors, such as carcinoid, chemodectoma, and pheochromocytoma. It occurs most frequently in the third decade of life and is more common in males. Unilateral nasal obstruction and epistaxis are the most common symptoms. The tumor may fill the nose and paranasal sinuses and involve the cribriform plate.

A staging system has been proposed by Kadish and colleagues that recognizes three stages ⁶:

Stage A: Tumor involves only nasal cavity

Stage B: Tumor extends also to sinuses

Stage C: Tumor extends beyond stage B

However, correlation of tumor extent with prognosis has not been as accurate as the relationship of clear surgical margins.

Esthesioneuroblastoma is known to have a slow but insidious malignant course, and death comes from local recurrence, intracranial invasion, and/or metastatic disease. Differential diagnosis must exclude lymphoma, melanoma, and metastatic neuroblastoma. The characteristic histologic picture includes a fibrillary intercytoplasmic background that on electron microscopy is identified as representing neuronal cell processes. The 5-year survival rate is approximately 50%, with a median survival of 58 months. When the cranial base is invaded, the survival rate drops to about 40%. Long-term recurrence has also been observed 10 to 20 years after the original diagnosis. This tumor is characterized by local persistence and recurrence. There is a 20% to 40% potential that this tumor will metastasize into cervical lymph nodes, lungs, and bones. The current modality of treatment includes a radical resection of the area involved that includes the cribriform plate with or without the attached dura followed by a full course of irradiation and possibly chemotherapy as well.

Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma is a rare tumor among non-Chinese patients, with an incidence of 1 in 100,000 among the North American population as compared with 2 in 100,000 among Chinese, especially those living in the Canton province of the People’s Republic of China. Several etiologic factors have been implicated in the development of nasopharyngeal carcinoma, for example, the Epstein-Barr virus and numerous external inhalation as well as dietary carcinogens. The male-to-female ratio heavily favors male patients (3:1), with an average age of onset of 45 years.

Clinically, the tumor appears to arise primarily at the superior or lateral aspect of the nasopharynx. The symptomatology often includes epistaxis, nasal and Eustachian tube obstruction, and eventual cranial nerve neuropathies (the fifth cranial nerve is most commonly involved). Histologically, these tumors are predominantly poorly differentiated carcinomas with a high propensity for metastatic regional spread, so that at the time of diagnosis, 50% of patients are expected to have regional disease. In the diagnostic evaluation, direct nasopharyngoscopy and biopsy, as well as a CT scan and MRI, provide for full assessment of the primary site. Irradiation is still considered a primary therapeutic modality for the nonkeratinizing squamous cell carcinoma of the primary site and the regional lymph node draining area.⁷ The cure rate, however, varies tremendously depending on the histologic type of the tumor, stage of the disease, and subsequent therapy. The most frequent recurrence of nasopharyngeal carcinoma is in the neck.⁸ Reirradiation of recurrent nasopharyngeal carcinoma gives a 5-year cure rate of only 14%, with a high chance of radiation-induced complications. It is important prognostically to separate patients with metastatic nasopharyngeal carcinoma in the neck on the basis of their response to the primary irradiation. If metastatic neck nodes disappeared completely following irradiation, the recurrence rate was only 13%. If nodes persisted throughout the course of irradiation, the recurrence rate was 91%.

With the advent of new approaches to the nasopharynx, surgery is becoming a therapeutic option for the treatment of resectable recurrent nasopharyngeal cancer with expected survival of over 50% (5 years). For tumors with very poor response to the primary radiotherapy (e.g., keratinizing squamous cell carcinoma, adenoid cystic carcinoma), surgery should be considered as the initial treatment.

Fibrous Dysplasia

Fibrous dysplasia is a progressive benign fibro-osseous lesion. Its natural growth is one of gradual expansion beyond its bony margins with concomitant displacement of surrounding soft tissue. It was first described by Lichtenstein in 1938.⁹ It may be placed into three categories on the basis of its clinical presentation. The monostotic form represents a localized disease to one osseous structure and is the most frequent form (up to 70%). A polyostotic form involves several bones but usually on the same side of the body. Here the frequency ranges from 30% to 50%. The third form is disseminated, in which numerous bones are involved, along with the possibility of extraskeletal developments such as skin pigmentation and precocious puberty. The incidence ranges from 3% to 30%. These individual clinical forms retain their categorization during the course of the disease and do not seem to change from, for example, the monostotic to the polyostotic form. Fibrous dysplasia is more common in females. In the head and neck region (0.5% of all head and neck tumors), it is the maxilla, frontal bone, mandible, and parietal and temporal bones that are most frequently involved. It is of interest that the progression of the disease is often limited after completion of skeletal maturation.¹⁰

The clinical symptomatology usually includes swelling at the tumor site with displacement of surrounding soft tissues. For example, diplopia, when present, is usually caused by mechanical displacement of the globe. If the cribriform plate is directly involved, alteration in olfaction can be perceived. Histologic verification can be considered in addition to the clinical and radiographic examination. In the differential histologic diagnosis, fibrous dysplasia may mimic meningioma, and sarcoma is also a possibility. Radiographically, a sclerotic form manifests itself with dense bone. The cystic and pagetoid forms are distinguished radiographically from each other by the greater amount of fibrous component in the former.

Fibrous dysplasia can be treated by surgical resection when functional or esthetic deformity warrants it.¹¹ Full preoperative evaluation should include CT scan, with and without contrast, in the axial and coronal planes with bone algorithms.

Osseous reconstruction of the surgical defect is necessary only when the tumor involves key aspects of the craniofacial skeleton. Autogenous bone graft or alloplastic materials can be used. In the orbital region, most of the fibro-osseous lesions involve the orbital roof. Prolonged ocular displacement by the tumor often produces a secondary concavity in the orbital floor. This must be taken into account, since after orbital tumor removal superiorly, the globe may not return to the expected normal level. Secondary bone grafting of the deformed orbital floor may have to be considered.