JBR–BTR, 2005, 88: 144-145. TUBEROUS SCLEROSIS AND SUBEPENDYM AL GIANT CELL ASTROCYTOM A V. Lam brecht, J.W. Van Goethem , O. Özsarlak, M . M aes, P.M . Parizel 1 Key-word: sclerosis, tuberous Background: A 6-year-old boy, presenting w ith facial adenom a sebaceum , was referred by the derm atologist for an M RI of the brain. A D B C E F 1A 1B 1C Fig. 1D 1E 1F 1. Departm ent of Radiology, University Hospital Antw erp, Edegem , Belgium TUBEROUS SCLEROSIS AND SUBEPENDYM AL GIANT CELL ASTROCYTOM A — LAM BRECHT et al. Work-up M RI of the brain (Fig. 1) show s on axial FLAIR im age (A) focal cortical hyperintensities. The right lateral ventricle is dilated. Axial T2-w eighted im age (B) dem onstrates the presence of an inhom ogeneous m ass, slightly hyperintense com pared w ith w hite m atter, in the right lateral ventricle. Shift of the septum pellucidum to the left is seen. Hypointense subependym al nodules protrude into the ventricular lum en. On coronal T2-w eighted im age (C), the m ass is located near the foram en of M onro and extends inferiorly through the foram en into the third ventricle. On the sagittal T1-w eighted im age (D), the m ass is iso- to hypointense com pared w ith the surrounding w hite m atter. On the Gadolinium -enhanced axial T1-w eighted im age (E), there is intense enhancem ent of the ventricular m ass and a slightly enhancing subependym al nodule is noted in the left lateral ventricle. Axial GRE T2* -w eighted im age (F) show s calcification in the subependym al nodules along the lateral ventricle surface. Radiological diagnosis Based on the clinical presentation of adenom a sebaceum in association w ith the im aging findings of cortical hyperintensities and subependym al nodules, the diagnosis of tuberous sclerosis was m ade. A m arkedly enhancing, intraventricular tum or near the foram en of M onro, in a patient w ith tuberous sclerosis is considered typical for subependym al giant cell astrocytom a. Discussion Tuberous sclerosis (TS), also know n as Bourneville’s disease, is a phakom atosis, m anifested by ham artom atous m alform ations in m ultiple organ system s. It is considered as a com plex autosom al dom inant inherited disorder, m ainly related to abnorm alities in chrom osom es 9 and 16. The approxim ate incidence is estim ated at about 1 in 50,000 to 1 in 10,000 live births, although a ‘form e fruste’ of the di-sease is probably m uch m ore com m on. The high num ber of sporadic cases (50-80%) can be explained by an underestim ation of patients w ith m inim al expression or penetrance. The classic clinical triad of seizures, m ental retardation and adenom a sebaceum is found in less than half the patients. Adenom a sebaceum are 145 raised, red papules on the face, m ainly around the nose. Other features are hypom elanotic m aculae on the trunk and extrem ities, shagreen patch (ovalshaped nevoid plaque, skincoloured or occasionally pigm ented, sm ooth or crinkled, appearing on the trunk or low er back), (peri)ungual fibrom a, retinal ham artom as, renal angiomyolipom a and cysts, visceral adenom a, cardiac rhabdom yom a and skeletal bone islands. The cerebral hem ispheres are the m ain site of involvem ent. About 95% of patients present w ith ham artom as in the periventricular subependym al region or anyw here else in the w hite m atter or cortical regions. The cortical ham artom as or ‘tubers’ flatten the gyri, giving them a m ore pachygyric appearance. Subependym al ham artom as or nodules m ost com m only occur at the head of the caudate nucleus. They are iso- or hypointense on T1-WI and hyperintense on T2-WI, som etim es enhancing. Calcification w ithin these ham artom as increases w ith age. Subependym al giant cell astrocytom as (SEGA) are alm ost exclusively observed in patients w ith TS and probably arise from a subependym al nodule in the ventricular wall. Am ong all patients w ith TS about 6%16% have a SEGA, w ith m ost cases occurring in the 1st and 2nd decades. Because these tum ors are nearly alw ays located at the foram en of M onro, obstructive hydrocephalus of the lateral ventricles is the m ost com m on cause of sym ptom s. SEGA enlarges slow ly and is histologically benign. Calcification is com m on. On CT- and M R-im ages, the tum or appears heterogeneous, iso- to hypoattenuated on CT, iso- to hypointense on T1-WI and hyperintense on T2-WI w ith intense enhancem ent follow ing contrast adm inistration. Periodic followup M RI in patients w ith TS is recom m ended and current neurosurgical opinion supports resection of a SEGA in case of sym ptom s or docum ented grow th. Bibliography 1. Koeller K.K., Sandberg G.D.: Cerebral Intraventricular Neoplasm s: Radiologic-Pathologic Correlation. Radiographics, 2002, 22: 1473-1505. 2. Osborn A.G.: Diagnostic neuroradiology. M osby 1994, chapter 5: Disorders of histogenesis: Neurocutaneous Syndrom es. p. 93-98. 3. Reim er P., Parizel P.M ., Stichnoth F.A.: Clinical M R-Im aging. 2nd edition, chapter 16: M agnetic Resonance Im aging of Pediatric Patients. Kam m er B.: p. 501.