Orbital pseudotumor--historical origin and modern relevance.

PURPOSE: To translate the original article from German in order to understand what the author was describing when Birch-Hirschfeld first used the diagnosis of orbital pseudotumor in 1905. To study why he used that diagnosis in the context of medical care and orbital diagnosis at the beginning of the twentieth century. Then to determine whether the term still has scientific relevance today. DESIGN: Perspective. RESULTS: In 1905, orbital pseudotumor was used as a term to describe clinical situations in which modern scientific methods would have provided more accurate and specific diagnoses. The original reasons for its use were a consequence of the limitations of medical care at the juncture of the nineteenth and twentieth centuries and the nature of orbital diseases more than a century ago. CONCLUSIONS: Orbital pseudotumor should no longer be used as a diagnosis because it is not based on current scientific knowledge. It is not specific and it hinders the application of diagnoses that are more useful in patient management.

Radiologic evaluation of the ear anatomy in pediatric cholesteatoma.

The aim of the study was to describe computed tomography (CT) findings in middle ear cholesteatoma in pediatric patients. A cohort of 32 children with cholesteatoma (3-14 years old) entered the study. From them, 30 presented acquired cholesteatoma (AC), and 2 presented congenital cholesteatoma. All of the children were investigated using CT before surgery of the middle ear and mastoid. Computed tomography was performed with 1- or 2-mm axial and coronal sections of both temporal bones. Nineteen children with AC (63.3%) revealed a diffuse soft-tissue density isodense with muscle, whereas in 6 of them, the mass mimicked inflammation. The remaining revealed localized soft-tissue mass with partially lobulated contour. In AC, ossicular erosion was detected in 23 cases (76.7%), abnormal pneumatization in 19 cases (63.3%), and erosion-blunting of spur and enlargement of middle ear or mastoid in 8 cases (26.7%). The 2 congenital cholesteatomas revealed soft-tissue mass with polypoid densities, while a semicircular canal fistula was detected in one of them. High-resolution CT facilitates early diagnosis and appropriate treatment of pediatric cholesteatoma by assessing the anatomic abnormalities and the extent of disease, which are crucial in middle ear and mastoid surgery.

Digital volume tomography: radiologic examinations of the temporal bone.

OBJECTIVE: We evaluated the clinical applicability and the value of digital volume tomography for visualization of the lateral skull base using temporal bone specimens. MATERIALS AND METHODS: Twelve temporal bone specimens were used to evaluate digital volume tomography on the lateral skull base. Aside from the initial examination of the temporal bones, radiologic control examinations were performed after insertion of titanium, gold, and platinum middle-ear implants and a cochlear implant. RESULTS: With high-resolution and almost artifact-free visualization of alloplastic middle-ear implants of titanium, gold, or platinum, it was possible to define the smallest bone structures or position of the prosthesis with high precision. Furthermore, the examination proved that digital volume tomography is useful in assessing the normal position of a cochlear implant. CONCLUSION: Digital volume tomography expands the application of diagnostic possibilities in the lateral skull base. Therefore, we believe improved preoperative diagnosis can be achieved along with more accurate planning of the surgical procedure. Digital volume tomography delivers a small radiation dose and a high resolution coupled with a low purchase price for the equipment.

The optic nerve: radiologic, clinical, and pathologic evaluation.

The radiologic investigation of the optic nerve plays an integral part in the diagnostic evaluation of diverse lesions of the optic pathways including inflammatory diseases, vascular disorders and benign and malignant tumors and these radiologic modalities consist principally of CT and MR imaging and, in vascular lesions, MR angiography and conventional angiography. The selection of radiologic studies and their focus is based on the ophthalmologic examination where the ophthalmologist can often determine the suspected location of lesions in the anterior or posterior visual pathways. Furthermore, inspection of the eye, including adnexal structures and funduscopy, provides additional information in the clinical assessment of these patients. With technical advances in the last few years, CT and MR imaging can detect lesions and determine their location and extent with high sensitivity and specificity. This article discusses the radiologic, clinical, and pathologic evaluation of the optic nerve.

Hodgkin 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. Clinical parameters, however, can be helpful in differentiating the two broad categories of lymphomas, and subtypes of lymphomas have predilections for different sites within the head and neck. HL is most commonly located in the lymph nodes of the neck and mediastinum. Marginal-zone lymphoma has an affinity for the ocular adnexa, salivary glands, larynx, and the thyroid gland. Diffuse large B-cell lymphoma is commonly encountered in the paranasal sinuses, mandible, maxilla, and Waldeyer ring. Burkitt lymphoma occurs more frequently in children and young adults and frequently affects the maxilla and mandible, with a greater distribution of involvement at a lower frequency. On imaging studies, the lymph nodes of HL and NHL are homogeneous and variable in size, with an average diameter from 2 to 10 cm. They may enhance slightly to moderately, display necrosis before and after treatment, and display calcification post-treatment. NHL in extranodal sites in the head and neck (nasopharynx, Waldeyer ring, oral cavity, and larynx) manifests frequently as a submucosal mass accompanied [figure: see text] by polypoid, bulky masses with a smooth mucosal surface. Clinically aggressive lymphomas, such as Burkitt lymphoma, diffuse large B-cell lymphoma, and NK-/T-cell lymphomas are characterized by destruction of the maxilla, mandible, and bones around the paranasal sinuses, which is indistinguishable from bony destruction in other malignant tumors, such as SCC. Contrast CT is indicated for evaluation of cervical lymph nodes; the chest, including the mediastinum; the pelvic cavity; paranasal sinuses; and orbits. CT is also useful for detection of bone destruction involving the base of the skull, paranasal sinuses, and the mandible or maxilla. 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.

Lesions of the maxilla: crossroads of the head and neck.

The maxilla may be involved by a wide range of pathologic conditions. Lesions originating in the maxilla may involve the adjacent orbit, oral cavity, or retroantral spaces. Recognition of this relationship plays an important role in diagnosis, prognosis, and presurgical planning.

Malignant 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. CT in the axial and coronal planes with 3- to 5-mm sections is the primary modality and is best in the evaluation of bony erosion of the mandible and maxilla. Furthermore, lymph node metastases in the neck are optimally evaluated by contrast CT with 5-mm axial sections. MR imaging is preferred for soft tissue assessment because of the greater contrast resolution. It is therefore the first modality in the assessment of tongue carcinomas, oropharyngeal cancer, and tonsillar lesions. The MR examination should be performed with thin-section imaging, applying T1, T2, and T1-GD-DTPA in the axial and coronal planes, with sagittal sections added for paramidline lesions involving the tongue, lips, anterior floor of the mouth, subdivided according to anatomic locations. The local spread, lymph node metastases, prognosis, and therapeutic approaches vary with the location of the lesion represented by a carcinoma either squamous or undifferentiated in 90% of cases. 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.

Nasopharynx: clinical, pathologic, and radiologic assessment.

NPC represents 0.2% of malignant disease in the white population but is more common in southern China, among Chinese in East Asia and the United [figure: see text] States, and in North Africa, including Saudi Arabia. NPC in these ethnic groups tends to manifest at a younger age. Undifferentiated carcinoma is the most common histopathologic type and is associated with EBV. The tumor is optimally assessed with CT and MR imaging for staging; PET scanning provides optimal assessment of recurrent tumor or small lymph node metastases. The primary tumor in the nasopharynx may be small and infiltrating, causing no or only a small mass effect in the nasopharynx. In these cases, obliteration of fat planes and loss of muscle boundaries are important diagnostic findings, which are best evaluated with MR imaging including, Gd-DTPA with fat suppression. The size of the NPC varies from 1 to 2 cm to large tumors that extend to the oropharynx, PPS, nasal cavities, paranasal sinuses, and orbits. Skull base erosion is independent of the size of the nasopharyngeal tumor and ranges from slight erosion to extensive destruction. A concomitant finding is intracranial invasion, predominantly to the basal cisterns and cavernous sinuses associated with cranial nerve palsies. Intracranial invasion should be assessed with contrast MR imaging. Lymph node metastases in the neck are present in 90% of cases and are bilateral in 50% of cases. In a small percentage of cases, extension of lymph node metastases to the mediastinum and hilar areas are encountered. Distant metastases involve the lungs, skeleton, and liver, and occasionally the choroid. They are usually present at the initial presentation [figure: see text] and increase in frequency in advanced disease and in recurrent tumors. In addition, the metastatic lymph nodes in the neck reveal no specific imaging features that would allow differentiation from other lymph node metastases. They may be discrete, often multiple, and large and bulky displaying a variable degree of necrosis and enhancement following introduction of contrast material. Local recurrence manifests commonly within the first 2 to 3 years posttherapy and is optimally evaluated by MR imaging and PET scanning.

Cystic lesions of the mandible and maxilla.

Cystic lesions appearing in the maxilla and mandible have been shown with their typical radiographic features. In addition, this article has presented radiographic techniques used to diagnose these lesions. Cysts of the jaws are classified into two categories: odontogenic and nonodontogenic. Key features to differentiate among these cysts have been discussed. Finally, the article discussed the differentiation of jaw cysts from benign tumors that appear in the jaws.

Malignant tumors of the mandible and maxilla.

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. The osteogenic sarcoma is the most common sarcomatous lesion in the mandible and is suggested when a bone-forming matrix with sclerosis is found within the tumor on CT images. Some benign lesions may mimic a malignant tumor on imaging studies. In such cases, a biopsy is indicated to establish the diagnosis by histopathologic means. 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.