The role of computed tomography in the evaluation of neck masses

Contrast Enhancement of Pathologic Lymph Nodes Demonstrated by Computed Tomography

Enlarged mediastinal, retroperitoneal and pelvic lymph nodes are often difficult to differentiate from vascular structures. Contrast medium is therefore used to help to discriminate arteries and veins from lymph nodes. This study was undertaken to investigate the degree to which pathologic lymph nodes become enhanced after an intravenous bolus injection of contrast medium. Computed tomography was performed in 25 patients with enlargement of retroperitoneal lymph nodes due to primary lymphoproliferative disease or metastases. A dynamic sequence of a well delineated lymph node was obtained over a period of two minutes. Contrast enhancement was seen in all lymph nodes, but of varying degree. The enhancement was correlated to that observed in the inferior vena cava. Most examined lymph nodes showed slight or moderate enhancement, but in five instances strong enhancement, more than 75 per cent of that of the vena cava, was found. These nodes could possibly have been misinterpreted as blood vessels.

Imaging evaluation of lymphadenopathy and patterns of lymph node spread in head and neck cancer

Accurate and consistent characterization of metastatic cervical adenopathy is essential for the initial staging, treatment planning and surveillance of head and neck cancer patients. While enlarged superficial nodes may be clinically palpated, imaging allows identification of deeper adenopathy as well as clinically unsuspected pathology and thus imaging has become an integral part of the evaluation of most head and neck cancers patients. This review will focus on the evaluation of cervical adenopathy, summarizing the currently used nomenclature and imaging approach for determining cervical lymph node metastases in head and neck malignancies. The imaging-based classification, which has also been adopted by the American Joint Committee on Cancer, will be presented, the morphologic characteristics used to identify metastatic nodes will be reviewed and the typical nodal spread patterns of the major mucosal cancers of the head and neck will be examined.

Laryngeal schwannomas

As laryngeal schwannomas are a threat to breathing, they must be removed. CT and MR provide an accurate pre-operative work-up of these lesions. The clear delineation of the tumoral attachment to the larynx proved to be very useful in the difficult management of our second patient. Our two laryngeal schwannomas exhibited a similar appearance which differed from those of the few other laryngeal nerve sheath tumors reported in the literature The low attenuating outer part correlated with Antoni B areas. The denser enhancing inner part correlated with Antoni A areas containing large vessels. This unusual tumoral appearance, which has been observed in some other peripheral schwannomas, must bring this diagnostic possibility to mind. However, this clearly contrasting distribution of the two components of schwannomas is not the most commonly observed in other locations. More reports are needed to establish whether this special appearance is characteristic of laryngeal location.

Extracranial and extraspinal nerve sheath tumors: computed tomographic evaluation

Thirty-five patients with 37 peripheral nerve sheath tumors (NST) (16 schwannomas, 11 neurofibromas, 5 plexiform and 1 diffuse neurofibroma, and 4 malignant NST) were studied respectively. The benign NST usually appeared on CT as well-defined oval, spherical or fusiform masses, centered at the expected anatomic location of a cranial, spinal, autonomic or peripheral nerve with characteristic displacement of adjacent muscles and blood vessels. None of the schwannomas appeared homogeneously hypodense on IV enhanced CT, whereas close to half of neurofibromas and plexiform neurofibromas were so. This fact, which had not been reported in the past, may be related to differences in inherent vascularity and blood-nerve barrier (fenestrated blood vessels) between schwannomas and neurofibromas and may be a useful distinguishing CT feature. The most reliable, though not infallible criterion of malignant NST was poor definition of their margins. Ninety-two per cent of NST (34 out of 37) were diagnosed or included in a limited differential pre-operatively.

Neurogenic neoplasms in the head and neck region

Thirteen cases of neurogenic tumor in the head and neck region experienced during the past fifteen years were reported. Six of them were neurilemmomas, three neurofibromas associated with von Recklinghausen's disease, two ganglioneuromas and two paragangliomas (chemodectomas). Representative cases were reported in detail in conjunction with considerations regarding diagnosis, treatment, and histopathologic findings by reviewing pertinent papers.

Hyperdense pelvic and inguinal lymph nodes

This small series reports on the computed tomography appearance of hyperdense iliac, inguinal, and femoral lymph nodes in four cases of lymphoma and one case each of ovarian and breast carcinoma. The mean attenuation value of the lymph nodes was 93.8 Hounsfield units (HU), compared to 61 HU for adjacent muscle and 110.7 HU for blood vessels. A relatively homogeneous enhancement pattern was noted, which could not be directly related to hypervascularity, inflammation, or previous treatment with drugs or radiation.

Computed tomography of the cranio-cervical lymphatic system: anatomical and functional considerations

As an initial route of the spread of inflammatory and neoplastic pathology, the complex lymphatic system of the cervical region assumes an important part of the examination in patients with extra-axial disease of the head and neck. In addition, the often overlooked cranio-facial lymphatics must also be routinely investigated in order to forward the understanding and sensitivity of the neuroradiologic evaluation of primary sites of disease propagation from these areas.

CT of the paranasal sinuses

CT scanning has allowed the radiologist to image paranasal sinus disease with an accuracy and detail never before attainable. This information has made the imager an important member of the physician team that evaluates the operability and treatment planning of these patients. The protocol of the CT examination is discussed, the normal CT anatomy is reviewed and an approach to evaluating both inflammatory and malignant disease is presented.

High resolution computed tomography, Part 1: Soft tissues of the neck

Normal and pathologic anatomy of the soft tissues of the neck is clearly delineated with high resolution computed tomography (CT). The CT densities of soft tissues, fat, and enhanced blood vessels are strikingly different from each other and, therefore, mass lesions are clearly discernable. Often, a histologic diagnosis may be suggested with a high level of confidence based on the location and tissue characteristics.

The value of CT scanning in the diagnosis of tuberculous lymphadenitis of the neck

A case of tuberculous lymphadenitis of the neck is presented. The diagnosis was confirmed by surgery and pathologic section.

Computed tomographic evaluation of neonatal neck masses

Two cases of neonatal neck masses are presented where computed tomography was valuable in the diagnosis, as well as determining the extent of involvement.

Computed tomography of the nasopharynx and neck

Computed tomography (CT) is unparalleled for evaluation of the nasopharynx and the neck in comparison with other radiologic modalities. Its ability to demonstrate soft tissue and bone abnormalities has established its role as a primary method of radiologic diagnosis, frequently obviating the need for further radiologic elaboration. Furthermore, in many cases, CT provides distinction among inflammatory, neoplastic, and traumatic conditions.

CT evaluation of a tympanic-jugular chemodectoma: a case report

The authors describe a case of a chemodectoma involving the tympanic-jugular region, studied by means of Computed Tomography. They underline the utility of this method in spatial evaluation of such tumors.

High-dose computed tomography in the evaluation of low attenuation lesions in the neck

Recent reports have established the clinical utility of computed tomography (CT) in the evaluation of jugular vein thrombosis. Other abnormalities of the soft tissues in the neck can mimic this condition. This study reviews the pertinent normal soft tissue and vascular anatomy of the neck and describes the use of high-dose CT in the evaluation of low attenuation lesions in this area. Various abnormalities are compared and contrasted, including cystic hygroma, neoplasm, abscess, and venous thrombosis.