Neuroradiological manifestations of suprasellar pituitary adenomas, meningiomas and craniopharyngiomas

Imaging paediatric endocrine disorders

Disorders of growth and development, including delayed and precocious puberty may be idiopathic, constitutional or due to a disorder of one of several endocrine systems including the hypothalamic-pituitary system, the adrenal and the thyroid. Sonography is of great importance in the classification of precocious puberty in children. Skeletal maturation assessment is useful to evaluate the severity of the growth disorder and to monitor subsequent therapy. Magnetic resonance imaging and computed tomography are essential in the study of the pituitary and central nervous system. MRI has special advantages in the imaging of the hypothalamic-pituitary region. The thyroid gland and its function are still best imaged with radionuclide scintigraphy. Sonography can play a complementary though less important role. Hypoparathyroidism, pseudohypoparathyroidism and pseudopseudohypoparathyroidism although rare are more common in children than primary hyperparathyroidism. Valuable clues as to the presence of these conditions can be gained by examination of the plain radiographs. Confirmation of their diagnosis still rests with the biochemical and endocrine profile.

Infrasellar craniopharyngioma

A rare case of infrasellar craniopharyngioma mainly occupying the paranasal sinuses, the infratemporal fossa and the skull base is presented. The patient had been treated by an otolaryngologist as a case of mucocele of the sphenoid and ethmoid sinuses because the biopsy specimens obtained at endonasal surgery failed to confirm the true diagnosis. Computed tomography (CT) showed multi-lobulated low density cysts in the paranasal sinuses, infratemporal fossa and skull base, and the cyst wall was enhanced. Magnetic resonance Imaging (MRI) revealed the cysts to have high intensity in both T1- and T2-weighted images, and excellent three-dimensional visualization was obtained. Characteristic motor-oil-like fluid was aspirated during transnasal surgery and the diagnosis of craniopharyngioma was confirmed by histological examination.

Giant cystic craniopharyngiomas

Three cases of giant cystic craniopharyngiomas with large areas of extension beyond the suprasellar area are presented. The magnetic resonance (MR) appearance in one case is described. These giant tumors had large, multilobulated cysts that comprised the bulk of the tumors. In one case, there was an unusual extension of the large tumor cyst into the lateral ventricle. In two cases, the tumors extended to the level of the foramen magnum. On CT, the cyst contents of these two tumors were hyperdense and became hypodense postoperatively. All three tumors harbored calcifications in the form of clumps in the suprasellar region and rim calcifications around the cysts. None of the tumors exhibited contrast enhancement. A literature review of the radiographic features of craniopharyngiomas is discussed.

Craniopharyngioma in children and adults. Correlations between radiological and clinical manifestations

We studied the radiological and clinical manifestations of craniopharyngioma in 22 children and 29 adults. The tumours tended to be smaller in adults than in children, and non-calcified, more often solid than cystic and suprasellar than suprasellar-intrasellar. Small tumours were associated with symptoms which had long been overlooked. The size of the tumour did not influence the results of surgery in children, but in adults total removal was more often successful for small tumours. In the children total removal was achieved least often with calcified and suprasellar-intrasellar tumours. Pre-operative skull radiography was abnormal in all except one of the children but in only half of the adults. Sclerosis of the sella floor and erosion of the dorsum sellae are early signs which are easily overlooked.

Influence of transsphenoidal hypophysectomy on visual deficit due to a pituitary tumour

The effect of transsphenoidal hypophysectomy is presented in 60 patients with visual impairment due to a pituitary adenoma, derived from a total series of 194 patients. The preoperative visual acuity and visual fields were compared with those one year after operation. The visual field loss was estimated using a semi-quantitative method. Seventy-two eyes had diminished visual acuity, and this improved in 45 eyes (63%). Visual field loss was present in 102 eyes and this improved in 71 eyes (70%). Improvement of either visual acuity and/or visual field was found in 84 eyes (78%). In 16 patients (27%) vision became normal after operation. Improvement of the visual acuity was usually accompanied by an improvement in the visual fields.

Microsurgical management of tuberculum sellae meningiomas. Results in 28 consecutive cases

A series of 28 cases of meningioma of the tuberculum sellae is reviewed. This tumor was most frequent in the fifth decade, with a clear predominance in women. Neurological and endocrine deficits were minimal, whereas ophthalmologic signs were always present. Visual deficits were bilateral in cases with more than a 1-year history. Osteoma of the tuberculum sellae was rare and had no correlation with tumor size. Angiography of the internal carotid artery was found useful in demonstrating vascular displacements and tumor blush. Computed tomography was the most reliable diagnostic tool. All patients underwent a unilateral pterional craniotomy using the operating Outside of patients with total blindness, improvement of visual acuity was the rule, even in cases of long-term duration. Best results were obtained in patients operated upon within 1 year of the onset of visual symptoms.

Differentiation of large suprasellar masses by evaluation of the superior margin

Differentiation of suprasellar masses by computed tomography criteria depends on intrasellar extension, patterns of calcification and enhancement, associated bony reaction, and cystic changes. In the case of a homogeneously enhancing suprasellar mass that does not exhibit any of these differentiating findings, separating a suprasellar meningioma from a large suprasellar pituitary adenoma has been quite difficult. We reviewed the computed tomography findings of 42 such tumors. There were 19 meningiomas and 23 pituitary adenomas chosen that had few or none of the commonly applied findings used in differentiation. Evaluation of the superior contour of these masses seems a reliable sign to use in this situation. A single upward convex curve correlated with a meningioma in 15 of 19 cases (78%), whereas a multiple upward convex curve correlated with a pituitary adenoma in 19 of 23 cases (82%). Although some pitfalls were encountered when employing this sign--such as pseudolobulations caused by the adjoining cavernous sinus, dural, or vascular structures--it nonetheless led to the correct diagnosis in approximately 80% of cases.

Current approaches to hypothalamic-pituitary radiology

Currently computed tomography (CT) is the primary imaging modality for pituitary and hypothalamic lesions, although it is probable that NMR will supersede it. The range of size of the normal pituitary is considerable, with relatively larger glands occurring in adolescence and females of childbearing age. Asymptomatic microadenomas and cysts are not infrequent so that small low-density lesions in a gland on the borderline of enlargement can only be assessed in relation to clinical presentation. Patients presenting with clinical or biochemical evidence of abnormal pituitary hormone secretion or with an enlarged sella but without evidence of any neurological abnormality are likely to have either a small pituitary tumour or an empty sella and are investigated by thin section high resolution CT to produce coronal and sagittal images. Visual defects, paralysis of ocular muscles or hypothalamic disturbances, in the absence of clinical evidence of hypersecretion of pituitary hormones, may be due to a variety of pathologies. These cases are elucidated by plain plus contrast-enhanced CT, supplemented as necessary by angiography and computed cysternography after injection of non-ionic contrast media. Hypothalamic disturbances may occasionally complicate cerebral malformations which are also elucidated by cranial CT.

The superior ophthalmic vein and tumours of the sellar area

The venous drainage dynamics of the cavernous sinus were studied by means of 50 carotid angiograms and 18 orbital phlebographies performed on 47 patients with various tumours of the sellar area. Normal blood flow direction in the superior ophthalmic vein (SOV) (from the facial veins into the cavernous sinus) was seen in supra- and small intrasellar tumours, but not in parasellar tumours. In bigger intrasellar tumours and in parasellar tumours the reversed blood flow direction visible in the SOV (from the cavernous sinus into the facial veins) indicated infiltration or compression of the cavernous sinus by tumour. The sign of reversed flow together with CT findings is useful in differential diagnosis and in planning surgical treatment for tumours of the sellar area.