Neuroimaging clinics of North America
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Malignant tumors of the mandible and maxilla are grouped into primary tumors that originate within the mandible and secondary lesions, predominantly oral cancers and metastatic lesions, that involve the mandible secondarily. The most common malignant tumors of the mandible represent SCCs of the oral cavity, notably carcinoma of the floor of the mouth and gingiva that invade the mandible secondarily. Metastatic disease, most commonly from the breast and lung, are not an uncommon malignant lesion in the mandible and may be the first manifestation of a malignant lesion outside the head and neck. ⋯ CT is indicated for assessment of bone destruction in the mandible before surgery or radiation therapy. MR imaging is the optimal modality for the assessment of marrow involvement and evaluation of the extraosseous soft tissue component. Finally, conventional films, frequently a Panorex view, are the initial radiographic examinations in suspected lesions.
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Neuroimaging Clin. N. Am. · Aug 2003
ReviewMalignant tumors of the oral cavity and oropharynx: clinical, pathologic, and radiologic evaluation.
Carcinomas of the oral cavity and oropharynx constitute approximately 2% to 5% of head and neck cancers. Alcohol abuse and tobacco chewing, including chewing Shamma, predispose individuals to the development of cancer in the oral cavity. CT and MR imaging are best suited in the evaluation of cancer of the oral cavity and oropharynx. ⋯ Some malignant lesions may mimic a benign tumor, such as the adenoid cystic or mucoepidermoid carcinoma. Histopathologic diagnosis is therefore necessary for the final diagnosis before treatment by surgery or radiotherapy. PET scanning is indicated in the following instances: in search of an unknown primary tumor in patients who have a neck mass secondary to carcinoma, if a recurrent carcinoma may be present, when there are metastatic N0 lymph nodes in the neck, or where CT is inconclusive for metastatic lymph nodes in the neck.
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Neuroimaging Clin. N. Am. · Aug 2003
ReviewHodgkin and non-Hodgkin lymphoma of the head and neck: clinical, pathologic, and imaging evaluation.
Lymphomas are subdivided into HL and NHL and are more specifically classified into subtypes of HL or NHL according to the WHO classification. HLs involve the lymph nodes predominantly and only approximately 5% arise in extranodal sites, whereas 30% of NHLs present in extranodal sites. Imaging studies, including CT and MR imaging, cannot distinguish [figure: see text] HL from NHL, and cannot differentiate their various subtypes, necessitating a pathologic diagnosis. ⋯ MR imaging is preferred for the assessment of extension of lymphomas to different fascial spaces (parapharyngeal, masticator, infratemporal fossa, tongue, and nasopharynx) and for intracranial extension. Lymphomas are isodense to muscle on CT and circumscribed with distinct margins that occasionally display extranodal extension with less-well-defined margins and areas of necrosis within the tumor matrix. Lymphomas appear low in signal intensity on T1-weighted images and low to high in signal intensity on T2-weighted images, with variable, but usually low, enhancement following introduction of Gadolinium-DTPA (Gd-DTPA) contrast material.
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Neuroimaging Clin. N. Am. · Aug 2003
ReviewCysts and tumors of the oral cavity, oropharynx, and nasopharynx in children.
A wide variety of developmental and neoplastic lesions arise in the oral cavity, oropharynx, and nasopharynx in children. The clinical manifestations and cross-sectional imaging findings provide complementary information, which is used to establish a probable or definitive diagnosis. This article describes imaging techniques and findings for developmental cystic masses and solid tumors in the pediatric population.
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Neuroimaging Clin. N. Am. · Aug 2003
ReviewInfection of the facial area, oral cavity, oropharynx, and retropharynx.
Radiologists play an important role in the evaluation of upper neck infections. Although most oral cavity infections arise from diseased teeth, several other sources of infection need to be considered. The distinction between abscess and phlegmon is of particular importance. Cross-sectional imaging is frequently used to identify complications of the initial infection.