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Tuberous sclerosis. Part I. Clinical and central nervous system findings Karen S. Caldemeyer, MD,a and Ginat W. Mirowski, DMD, MDb,c Indianapolis, Indiana
TUBEROUS SCLEROSIS Tuberous sclerosis (TS) is an inherited disorder characterized by hamartomas that may occur in any organ system, but most often occur in the skin, brain, eye, heart, and kidney. Clinical pearls • Autosomal dominant inheritance; 66% to 86% of cases arise from spontaneous new mutations From the Department of Radiology, Division of Neuroradiology, Indiana University Medical Centera; the Department of Oral Surgery, Medicine and Pathology,b and the Department of Dermatology,c Indiana University Dental School. Reprint requests: Karen S. Caldemeyer, MD, Department of Radiology, University Hospital, 550 N University Blvd, RM 0279, Indianapolis, IN 46202-5253. E-mail:
[email protected]. J Am Acad Dermatol 2001;45:448-9. Copyright © 2001 by the American Academy of Dermatology, Inc. 0190-9622/2001/$35.00 + 0 16/1/111627 doi:10.1067/mjd.2001.111627
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• Prevalence 1/6000 • Two separate tumor suppressor genes may produce TS • TSC1 on chromosome 9q34 • TSC2 on chromosome 16p13.3 • Variable clinical spectrum—ranges from a single asymptomatic cutaneous hamartoma to involvement of multiple organ systems • Classic triad—epilepsy, mental retardation, and adenoma sebaceum, not seen in the majority of patients • Other neurologic manifestations—autism, behavioral disturbances, focal neurologic deficits, increased intracranial pressure • Hypomelanotic macules (ash leaf spots, confection macules, thumbprint macules) • One of earliest cutaneous signs • More than 90% affected persons have hypopigmented macules • May be seen in persons unaffected by TS
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Fig 1. A, Axial T1-weighted magnetic resonance (MR) image shows bilateral giant cell astrocytomas (long arrows) as well as multiple small subependymal nodules (short arrows). B, Coronal contrast-enhanced T1-weighted MR image shows bilateral enhancing giant cell astrocytomas (arrows) at the foramina of Monro. C, Axial T2-weighted MR image shows multiple cortical and white matter tubers (arrows).
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B Fig 2. A, Axial computed tomographic (CT) scan shows small calcified subependymal nodules (arrows). B, Axial T2-weighted MR image shows multiple cortical and white matter tubers (arrows), which are much less apparent on the CT scan. However, the small calcified subependymal nodules seen on the CT scan are not visualized on the MR image.
• Facial angiofibromas • One of the most common and specific cutaneous manifestations • Small, erythematous papules • Cheeks, nasolabial folds, chin, and occasionally ears and forehead • Develop in the preschool years • Enlarge and increase in number with time Central nervous system manifestations Eye • Retinal hamartomas—approximately 50% affected persons Brain • Subependymal nodules (abnormal neuronal and glial elements)—most common cerebral lesion • Cortical and white matter tubers (abnormal heterotopic giant cells) • Giant cell astrocytoma (Fig 1)—originates from subependymal nodule near foramen of Monroe, typically within the first 2 decades of life • Other findings—cerebral atrophy, cerebral infarct, cerebral aneurysm, arachnoid cyst Radiologic pearls • Calcification frequently seen in subependymal nodules and giant cell astrocytomas, less commonly seen in cortical and white matter tubers
• Calcification increases with the age of the patient • Calcification is best detected on computed tomography; however, magnetic resonance imaging is more sensitive for detecting small subependymal nodules and cortical and white matter tubers, especially when not calcified (Fig 2). BIBLIOGRAPHY Hahn JS, Bejar R, Gladson CL. Neonatal subependymal giant cell astrocytoma associated with tuberous sclerosis: MRI, CT, and ultrasound correlation. Neurology 1991;41:124-8. MacDonald IM, Bech-Hansen NT, Britton WA Jr, Green J II, Paterson M, Stone J.The phakomatoses: recent advances in genetics. Can J Ophthalmol 1997;32:4-11. Roach ES, Delgado MR. Tuberous sclerosis. Dermatol Clin 1995;13:151-61. Truhan AP, Filipek PA. Magnetic resonance imaging: its role in the neuroradiologic evaluation of neurofibromatosis, tuberous sclerosis, and Sturge-Weber syndrome. Arch Dermatol 1993; 129:219-26. Webb DW, Osborne JP. Tuberous sclerosis. Arch Dis Child 1995;72: 471-4.
