Childhood sarcomas often occur in the head and neck area and they are described in other sections. Unusual pediatric head and neck cancers include nasopharyngeal carcinoma, esthesioneuroblastoma, thyroid tumors, oral cancer, salivary gland cancer, laryngeal carcinoma, papillomatosis, and respiratory tract carcinoma involving the NUT gene on chromosome 15. The prognosis, diagnosis, classification, and treatment of these head and neck cancers are discussed below. It must be emphasized that these cancers are seen very infrequently in patients younger than 15 years, and most of the evidence is derived from case series.
Nasopharyngeal carcinoma arises in the lining of the nasal cavity and pharynx.[2,3] This tumor accounts for about one-third of all cancers of the upper airways. Nasopharyngeal carcinoma is very uncommon in children younger than 10 years but increases in incidence to 0.8 and 1.3 per 1 million per year in children aged 10 to 14 years and in children aged 15 to 19 years, respectively.[4,5] The incidence of nasopharyngeal carcinoma is characterized by racial and geographic variations, with an endemic distribution among well-defined ethnic groups, such as inhabitants of some areas in North Africa and Southeast Asia. In the United States, nasopharyngeal carcinoma is overrepresented in black children when compared with other malignancies.
Nasopharyngeal carcinoma is strongly associated with Epstein-Barr virus (EBV) infection. In addition to the serological evidence of infection, EBV DNA is present as a monoclonal episome in the nasopharyngeal carcinoma cells, and tumor cells can have EBV antigens on their cell surface. The circulating levels of EBV DNA, and serologic documentation of EBV infection, may aid in the diagnosis.
Three histologic subtypes of nasopharyngeal carcinoma are recognized by the World Health Organization (WHO). Type 1 is squamous cell carcinoma; type 2 is nonkeratinizing squamous cell carcinoma; and type 3 is undifferentiated carcinoma. Children with nasopharyngeal carcinoma are more likely to have WHO type 2 or type 3 disease.
Nasopharyngeal carcinoma commonly presents as nosebleeds, nasal congestion and obstruction, or otitis media. Given the rich lymphatic drainage of the nasopharynx, bilateral cervical lymphadenopathies are often the first sign of disease. The tumor spreads locally to adjacent areas of the oropharynx and may invade the skull base, resulting in cranial nerve palsy or difficulty with movements of the jaw (trismus). Distant metastatic sites may include the bones, lungs, and liver.
Diagnostic tests should determine the extent of the primary tumor and whether there are metastases. Visualization of the nasopharynx by an ear-nose-throat specialist using nasal endoscopy, examination by a neurologist, and magnetic resonance imaging of the head and neck can be used to determine the extent of the primary tumor. A diagnosis can be made from a biopsy of the primary tumor or of enlarged lymph nodes of the neck. Nasopharyngeal carcinomas must be distinguished from all other cancers that can present with enlarged lymph nodes and from other types of cancer in the head and neck area. Thus, diseases such as thyroid cancer, rhabdomyosarcoma, non-Hodgkin lymphoma, Hodgkin lymphoma, and Burkitt lymphoma must be considered, as should benign conditions such as nasal angiofibroma, which usually presents with epistaxis in adolescent males, and infectious lymphadenitis. Evaluation of the chest and abdomen by computed tomography and bone scan should also be performed to determine whether there is metastatic disease.