A range of sensitivities and specificities for detection of nodal disease are found in the literature, likely reflecting the highly operator dependent nature of this technique. US alone has been shown to be very sensitive (77.8%-96.8%) and specific (68.75%-97%) in detecting cervical nodal metastases [47,63-65]. One study has shown similar accuracy of US to MRI in the detection of the primary site in patients with suspected NPC, which suggests that US may have a role as a screening tool [93]. Variant 3: Suspected or diagnosed cancer of the paranasal sinuses or nasal cavity. Initial staging. Sinonasal tumors are rare neoplasms and make up only 3% of head and neck carcinomas and approximately 0.5% to 1% of all malignancies [94,95]. Despite its relatively small anatomic confine, a wide range of malignancies can arise from the sinonasal cavity. Neoplasms can be classified as either epithelial or nonepithelial. Of the epithelial tumors, squamous cell carcinoma is by far the most common malignancy and accounts for up to 80% of sinonasal cancers and, for this reason, will be the focus of the upcoming discussion. The maxillary sinus and nasal cavity Assessment of Head and Neck Cancer constitute the most common sites of origin [95,96]. The most frequent nonepithelial malignancies are malignant lymphomas, which comprise approximately 6% to 13% of extranodal lymphomas of the head and neck [95]. Additional malignancies encountered in this region include adenocarcinoma, salivary gland tumors, olfactory neuroblastoma, and melanoma, among others. Olfactory neuroblastomas are rare and constitute only around 2% of sinonasal tumors. They arise from the olfactory epithelium found at the roof of the ethmoid sinuses, cribriform plate, upper nasal septum, and superior turbinates. Because of its site of origin, olfactory neuroblastomas have a propensity to invade the anterior cranial fossa [96,97].
Staging and Post Therapy Assessment of Head and Neck Cancer. A range of sensitivities and specificities for detection of nodal disease are found in the literature, likely reflecting the highly operator dependent nature of this technique. US alone has been shown to be very sensitive (77.8%-96.8%) and specific (68.75%-97%) in detecting cervical nodal metastases [47,63-65]. One study has shown similar accuracy of US to MRI in the detection of the primary site in patients with suspected NPC, which suggests that US may have a role as a screening tool [93]. Variant 3: Suspected or diagnosed cancer of the paranasal sinuses or nasal cavity. Initial staging. Sinonasal tumors are rare neoplasms and make up only 3% of head and neck carcinomas and approximately 0.5% to 1% of all malignancies [94,95]. Despite its relatively small anatomic confine, a wide range of malignancies can arise from the sinonasal cavity. Neoplasms can be classified as either epithelial or nonepithelial. Of the epithelial tumors, squamous cell carcinoma is by far the most common malignancy and accounts for up to 80% of sinonasal cancers and, for this reason, will be the focus of the upcoming discussion. The maxillary sinus and nasal cavity Assessment of Head and Neck Cancer constitute the most common sites of origin [95,96]. The most frequent nonepithelial malignancies are malignant lymphomas, which comprise approximately 6% to 13% of extranodal lymphomas of the head and neck [95]. Additional malignancies encountered in this region include adenocarcinoma, salivary gland tumors, olfactory neuroblastoma, and melanoma, among others. Olfactory neuroblastomas are rare and constitute only around 2% of sinonasal tumors. They arise from the olfactory epithelium found at the roof of the ethmoid sinuses, cribriform plate, upper nasal septum, and superior turbinates. Because of its site of origin, olfactory neuroblastomas have a propensity to invade the anterior cranial fossa [96,97].