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Show J. Clin. Neuro-ophthalmol. 4: 209-212, 1984. Neuroradiological Clinical Pathological Correlations Bitemporal Hemianopsia DAVID M. LEFKOWITZ, M.D. ROBERT M. QUENCER, M.D. Case History A 55-year-old white male was found on a routine eye exam to have bitemporal hemianopsia. Additionally, partial field defects in the nasal quadrants of the right eye were detected and later determined by CT to be the result of an old right parieto-occipital infarct. Twelve years ago, the patient had the sudden onset of a severe headache and visual difficulties which resolved spontaneously. This was postulated to have been secondary to a pituitary apoplectic event. The patient has adult onset diabetes mellitus of 4 years' duration controlled by Diabenase. The patient was hospitalized for brain computed tomography (CT) (Figs. la-Id) and cerebral angiography. Discussion Based on the clinical presentation and the CT, the differential diagnosis consisted primarily of craniopharyngioma, diaphragma meningioma, pituitary macroadenoma, and aneurysm. Craniopharyngiomas are characteristically suprasellar tumors.) Most commonly, they are hypodense to the surrounding brain on noncontrast CT, although they can be iso- or even hyperdense particularly in the older age groups. Following intravenous contrast injection, rim enhancement is common although it is observed more frequently in children. 2 Calcification is also more common in children and typically is rim-like with or without an irregular central component. In our case, calcifications could not be clearly identified. Diaphragm meningiomas and pituitary adenomas that have extended into the suprasellar cistern characteristically are iso- to hyperdense before homogeneously enhancing. The punctate From the Department of Radiology, University of Miami School of Medicine, Miami, Florida. September 1984 and curvilinear peripheral enhancement noted in our patient made these choices unlikely. The types of pituitary macroadenoma most apt to be confused with a craniopharyngioma are those that are hypodense with ring enhancement. Bone erosion or destruction of the dorsum sellae or posterior clinoids is not a useful distinguishing factor, since this finding is extremely common in pituitary adenomas, but also can be seen in craniopharyngiomas and in diaphragma meningiomas. This type of erosion was not observed in our case (Fig. 2). Hyperostosis is only associated with the diaphragma meningioma; however, it can be subtle in this area, often leaving uncertainty as to its presence. Aneurysms in the suprasellar region typically are round and smoothly marginated. They are iso- to hyperdense lesions which densely enhance with contrast, although a portion may remain unenhanced if filled with thrombus. Peripheral calcifications as seen with craniopharyngiomas may be present in aneurysms present in an older age group. As with the other large suprasellar masses, bone erosion involving the dorsum may occur. A normal angiogram allowed us to rule out an aneurysm in our patient. In addition, pituitary ~acroadenomaor diaphragma meningioma, prevIOusly downgraded as possibilities from the CT appearance, were rendered even more unlikely, since a significant percentage of these tumors can have a vascular blush. Although these lesions can be avascular by conventional techniques, prolonged injection angiography (not done) may permit visualization of these tumors.3 Other suprasellar tumors were considered but judged unlikely for a variety of reasons. Optic or hypothalamic gliomas are not usually as well marginated, occur in younger age groups, and are seen commonly in association with neurofibro- 209 Bitemporal Hemianopsia Figure la. Nonenhanced coronal CT scan showing rounded slightly hyperdense suprasellar mass (arrows). The density within the sella is lower producing a plane of cleavage between the mass and the normal pituitary. Figure lb. A slightly more posterior plane shows the mass and its effect on the inferior third ventricle (arrowheads). 210 Journal of Clinical Neuro-ophthalmology t ) Figure Ie. A contrast enhanced coronal scan shows incomplete curvilinear peripheral enhancement (arrowheads) and some central irregular punctate areas of contrast enhancement. (d) Figure Id. Contrast enhanced axial scan. Same findings as in Fig. Ie. September 1984 211 'lpsia Bitemporal Figure 2. Lateral plain radiograph of the sku!: show that the sella and clinoid processes are nonnal. matosis. Subarachnoid cysts are of CSF density and have a characteristic sharp margin.4 Epidermoid and dermoid tumors share most of the CT and angiographic features of the childhood craniopharyngiomas in that they are low density (though nonenhancing), have mostly peripheral calcifications (although occasionally internal calcifications may be present), and no identifiable blush with routine angiography. Since our lesion was slightly hyperdense and contained no identifiable calcification, these possibilities were considered unlikely. At surgery, a tumor was found between the right optic nerve and the carotid artery, below and posterior to the optic chiasm. A thin transparent tumor capsule containing some calcifications was adherent to both the chiasm and basilar tip. After aspiration of thick, viscous whitish fluid from within the capsule, a subtotal resection was performed. Pathogically there were two types of cellular arrangements: 1) nests of benign squamous epithelium, and 2) cysts lined by tall columnar ciliated cells and mucin-producing cells. The typical ameloblastomatous differentiation seen in craniopharyngiomas was not observed. Two explanations were offered. The patient could have a mixed neoplasm with one component representing the stratified squamous epithelium lining of a 212 true craniopharyngioma, and the second containing the ciliated epithelial lining of Rathke's cleft tissue. Alternatively, the patient could have had a primary Rathke's cleft tumor with considerable squamous metaplasia of the ciliated epithelium. References 1. NumaguchL Y., Kishikawa, T., Ikeda, J., Fukni, M., Kitamara, K., Tsukamoto, Y., Hasno, K., and Matsaura, K.: Neuroradiological manifestations of suprasellar pituitary adenomas, meningiomas, and craniopharyngiomas. Neuroradiology 21: 67-74, 1981. 2. Fitz, CR., Wortzman, G., Harwood-Nash, D.C, Holgate, R.C, Barry J.F., and Boldt, D.W.: Computed tomography in craniopharyngiomas. Radiology 127: 687-691, 1978. 3. Namaguchi, Y., Kishikawa, 1., Ikeda, L Tsukamoto, Y., Fukui, M., Kitamara, K., and Matsaura, K.: Prolonged injection angiography for diagnosing intracranial neoplasms. Radiology 136: 387-393, 1980. 4. Banna, M., Baker, H.L., and Houser, O.W.: Pituitary and parapituitary tumors on computed tomography. Br JRadiol53: 1123-1143, 1980. Write for reprints to: Robert M. Quencer, M.D., Univers. ity of Miami School of Medicine, Department of RadIOlogy (R-130), P.O. Box 016960, Miami, Florida 33101. Journal of Clinical Neuro-ophthalmology |
