Patient 01: 01 - year - old boy.
Patient 02: 07 - year - old girl with seizures, mental retardation and papular forehead lesions.
Patient 03: 16 - year - old girl presenting with seizures.
Figure 01 (patient 01): nonenhanced CT scan in a patient with tuberous sclerosis reveals subependymal calcification on the right (arrow); there is also a hypodense foci in the deeper white matter of the right parietal region (arrow).
Figure 02 (patient 01): nonenhanced CT scan demonstrates multiple cortical tubers (white arrows), and hipodensity lesions in deeper white matter of both cerebral hemispheres (black arrows), which represent hamartomatous tissue.
Figure 03 (patient 02): plain film radiograph in a 07 - year - old girl with tuberous sclerosis shows two faint periventricular calcifications on both sides (arrows).
Figure 04 (patient 02): nonenhanced CT scan reveals bilateral calcified subependymal nodules at the foramina of Monro.
Figure 05 (patient 02): nonenhanced CT scan demonstrates multiple periventricular calcifications and cortical tubers (arrows) in both cerebral hemispheres.
Figure 06 (patient 03): contrast - enhanced CT scan shows bilateral calcified subependymal nodules at the foramina of Monro.
Figure 07 (patient 03): contrast - enhanced CT scan reveals calcified white matter lesion in the left cerebral hemisphere.
|Diagnosis: Tuberous sclerosis.|
Tuberous sclerosis (TS) is one of the neurocutaneous syndromes or ¨neurophakomatoses¨, along with neurofibromatosis, Sturge-Weber syndrome, Von Hippel Lindau disease and ataxia telangiectasia. The disease is an autosomal dominant disorder. Approximately 50% of cases are inherited and 50% are sporadic. No racial or sexual predilection has been detected.
Tuberous sclerosis is a systemic disease with prominent cutaneous, visceral and CNS manifestations. The vast majority of the lesions are hamartomas - indolent, slowly growing masses, composed of a disorganized arrangement of cells that are otherwise relatively normal. Other eponyms for TS include ¨cerebral sclerosis¨, ¨Pringle`s disease¨and ¨Bourneville disease¨.
The original diagnostic criteria of TS required all three elements of the classic Vogt triad: seizures, mental retardation and adenoma sebaceum, which is a papular facial nevus, more accuratelly termed facial angiofibroma. This classic appearance occurs in less than half of patients, and has now been replaced by the modern and more inclusive set of diagnostic criteria, with major and minor features.
1. Cardiac rhabdomyoma;
2. Cerebral cortical tuber;
3. Facial angiofibroma or forehead plaque;
4. Hypomelanotic macules (>3);
5. lung lynfangioleiomyomatosis;
6. Multiple retinal nodules hamartomas;
7. Nontraumatic ungual or periungual fibroma;
8. Renal angiomyolipoma;
9. Shagreen patch (nevus);
10. Subependymal giant cell astrocytoma;
11. Subependymal nodule.
1. Bone cysts;
2. Cerebral white matter lesions;
3. Confetti skin lesions;
4. Gingival fibromas;
5. Hamartomatous rectal polyps;
6. Multiple randomly distributed pit in dental enamel;
7. Multiple renal cysts;
8. Nonrenal hamartomas;
9.Retinal achromic patches.
Definite: two major features or one major feature plus two minor features;
Probable: one major feature plus one minor feature;
Possible: one major feature or two or more minor features.
Manifstations of tuberous sclerosis can become apparent in persons of any age, but most patients have clinical sumptoms before they are aged 10 years. Patients who have seizures before they are aged 5 years are more likely to have mental retardation than other patients.
Magnetic resonance (MR) is considered the modality of choice for the evaluation of the brain in patients with diagnosed or suspected tuberous sclerosis. Computed tomography (CT) is less sensitive than MR in the identification of cortical hamartomas and white matter abnormalities. MR is less sensitive than CT in the identification of calcification of the brain. Overall, CT reveals intracranial abnormalities in 85% of patients with TS. Abnormal radiological cerebral findings in this disease include cortical hamartomas, deep white matter lesions, subependymal nodules and subependymal giant cell astrocytoma.
The cortical hamartomas or tubers are the most characteristic lesion of tuberous sclerosis. Cortical tubers show age - related changes on CT scans. In infants, they appear as low - attenuation peripheral lesions within broadened cortical gyri (fig 02) and tend to become isodense in older children and adults. Calcification of these lesions also increase with age. Calcification is rare in infants. By age 10, calcified cortical tubers (fig 07) are present in up to 50% of patients with TS.
White matter abnormalities commonly present in patients with TS. On CT, these lesions appear as low - attenuation, well - defined areas within the cerebral white matter (fig 01 and fig 02) that usually do not enhance after intravenous contrast infusion. When calcifications occur it can involve part or all of the nodule.
Subependymal nodules (SENs) are found in 95% of patients with TS. Nearly two thirds are located near the caudate nucleus along the striothalamic groove (between the caudate and thalamus) of the lateral ventricles (fig 04, fig 05 and fig 06). Less commonly, the nodules may be detected along the frontal and the temporal horns. Third and fourth ventricular subependymal nodules are very infrequent. The SENs calcify progressively during the first two decades. So that by age 20 virtually 100% are hyperdense. The appearance of multiple subependymal calcifications on CT is classic for tuberous sclerosis (fig 05). Calcified SENs in this disease are often larger and fewer than the periventricular calcifications of congenital inflammatory disease. Periodic follow up imaging studies of lesions near the foramen of Monro are indicated because subependymal giant cell astrocytomas occur in this area.
In 10 - 15% of patients subependymal nodules may transform into giant cell astrocytoma (SGCA). This transformation is suggested by increasing diameter and contrast enhancement. SGCAs are classified as grade I glioma by the World Health Organization (WHO). They are frequently calcified, appear heterogeneous on CT and show intense but somewhat inhomogeneous enhancement following contrast administration. These tumors only rarely invade brain parenchyma. they tend to grow into the ventricle and because of their strategic location, near the foramen of Monro, they may cause obstructive hydrocephalus. Recurrence is rare and prognosis is good after surgical ressection.
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Case Number: 37366233Last Updated: 2013-02-03 The reader is fully responsible for confirming the accuracy of this content.
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