Radiology_Oct04 Introduction Meningio-angiomatosis (MA) is a rare congenital hamartomatous mal- formation of the leptomeninges often also involving the adjacent cerebral cortex. Some cases are associated with neurofibromatosis (NF) whereas oth- ers develop in isolation. Case report A 6-year-old girl presented after a prolonged grand mal seizure. She had suffered from recurrent focal seizures affecting her right side since 1 year of age and also suffered from a mild right-sided hemiplegia. There were no clinical or radiological stig- mata of NF. An electro-encephalo- gram (EEG) demonstrated abnormal electrical activity over both tem- poroparietal regions. An unenhanced computed tomography (CT) scan of the brain showed multiple areas of hyperinten- sity in the left parietal lobe extending in a linear radial fashion along a num- ber of gyni and sulci over the surface of the brain (Fig. 1a). Moderate con- trast enhancement was seen adjacent to some of these hyperintensities (Fig. 1b). The hyperintense areas appeared denser than blood. As there was no suspicion of any acute subarachnoid haemorrhage this was assumed to be calcification. On unenhanced T1-weighted magnetic resonance (MR) images no direct evidence of any meningeal thickening could be seen, although slight thickening and a mild increase in signal intensity was seen within the cortex over the convexity of the pari- etal lobe (Fig. 2a). No abnormal sig- nal intensity was noted in this area on T2-weighted or proton-density images, although some prominent vessels were seen over the brain sur- face (Fig. 2b). Bright signal was, how- CASE REPORT 27 SA JOURNAL OF RADIOLOGY • October 2004 Meningio- angiomatosis — case report and subject review I C Duncan FFRad (D) F I Spiro FRCR Sunninghill Hospital Sandton Johannesburg Fig 1a. Unenhanced axial CT scan showing linear hyperintense material over the surface of the left parietal lobe with extension into the sulci in keep- ing with calcified proliferative leptomeningeal tis- sue. Fig 2a. Unenhanced coronal T1-weighted MR scan showing no meningeal thickening over the left parietal lobe but slight increase in the signal intensity of areas of the surface cortex itself. Fig 2b. No significant signal abnormality is noted on either standard T2-weighted or proton-density images (illustrated here). Some prominent surface vessels are seen. Fig 2c. Coronal FLAIR image showing bright sig- nal arising from the thickened leptomeninges. Fig 1b. Contrast-enhanced CT scan at the same level showing some areas of contrast enhance- ment within the abnormal tissue. 28 SA JOURNAL OF RADIOLOGY • October 2004 ever, noted on the post-gadolinium FLAIR (Fig. 2c) and post-gadolinium T1-weighted images (Figs 2d - f). Digital subtraction arteriography was then performed. Selective left external carotid arteriograms showed no abnormal dural supply, whereas selective left internal carotid arteri- ograms showed enlargement of the posterior parietal branch of the left middle cerebral artery with some smaller slightly dysplastic looking branches seen in the same area as the abnormalities shown on the scan (Figs 3a - d). The diagnosis of meningiomatosis was made on the basis of the clinical and radiological findings, but the child has since been lost to follow-up with the result that no histological confirmation could be obtained. Discussion MA is a rare benign hamartoma- tous lesion of the cerebral cortex and adjacent leptomeninges, first described by Bassoe and Nuzum1 in 1915 in a patient with NF. The term ‘meningio-angiomatosis’ was first used in 1937 by Worcester-Drought et al.,2 who also first suggested that MA may represent a forme fruste of NF. Many cases have been reported in NF patients, but not all are associated with NF.3-5 In sporadic cases the male/female ratio is more equal and the mean patient age tends to be somewhat younger, children and young adults being affected. Patients typically present clinically with headaches and seizures but some cases are also found incidentally at autop- sy6,7 or during cranial imaging.8 In most cases the MA affects the cerebral cortex, usually in the frontal or tem- poral regions. Some cases may show CASE REPORT Fig 2d. Contrast-enhanced coronal T1-weighted image showing the enhancing thickened lep- tomeninges over the brain surface. Fig 2e. Contrast-enhanced axial T1-weighted image at the same level as Fig 2b showing the densely-enhancing surface tissue and sulcal extension. Fig 2f. Contrast-enhanced sagittal T1-weighted image showing the anteroposterior extent of the lesion. Note the radial extension within the sulci and possibly through the perivascular spaces as well. Fig 3a. Selective left internal carotid digital sub- traction arteriogram, lateral projection, showing enlargement of the posterior parietal branch of the left middle cerebral artery corresponding to the prominent surface vessel seen in Fig. 2b. Fig 3b. Same run, later image showing a local col- lection of slightly dysplastic looking branches over the affected cortex. No abnormalities were noted during the venous phase. Fig 3c. Same vessel, right anterior oblique view, again showing the relatively prominent parietal branch. Fig 3d. Same run, later image again showing the slightly dysplastic-looking vessels over the cortex. No abnormalities of the external carotid dural sup- ply were noted. CASE REPORT 29 SA JOURNAL OF RADIOLOGY • October 2004 involvement of the third ventricle, thalamus or brainstem.6,9 The characteristic pathological findings include leptomeningeal meningovascular fibroblastic prolifer- ation and a variable degree of lep- tomeningeal calcification.3,10 There is angiomatous proliferation within the meninges, sometimes with associated arteriovenous shunting. The fibro- blastic and angiomatous proliferation can extend in a linear fashion along the Virchow-Robin perivascular spaces, thereby appearing to ‘pene- trate’ the cortical grey matter.3 The degree of calcification can vary from numerous psammona bodies histo- logically to dense calcification and even ossification.8 Changes may also be seen in the adjacent brain cortex (mengiocephalo-angioneuromato- sis). The cortical changes include the presence of neurofibrillary tangles, thought to represent degenerative changes in entrapped neurons.6 On unenhanced CT scans the cal- cifications may be seen as either linear or granular in nature,3 whereas non- calcified areas or lesions may range from isodense to moderately hypo- dense with the low-density appear- ance probably representing a loosely packed cellular matrix consisting of prominent perivascular spaces and scattered meningeal spindle (fibrous) cells.7 The degree of contrast enhance- ment is variable. On MR scans the lesions tend to be iso- to hypointense to grey matter on T1-weighted images. Non-calcified areas or lesions are typically hyperintense on T2- weighted images with areas of dense calcification producing marked T2 shortening and thus appearing as hypo-intense areas often within the center of the lesion.3,8,10 Again contrast enhancement is variable. Angiographic findings also vary from normal through the presence of an avascular ‘mass’ to the finding of abnormal vessels.4,8,10 The differential diagnosis of MA includes the Sturge-Weber syndrome, meningioma, granulomatous menin- gitis (sarcoid or tuberculosis) and cal- cified infiltrating glioma. MA can be readily differentiated from Sturge- Weber syndrome in that the calcifica- tion in the latter is parenchymal (gyral) and is associated with brain tissue atrophy on sectional ima- ging and a venous collateral (‘pseu- dophlebitic’) pattern in the affected regions at arteriography.3 Total surgical resection is the treat- ment of choice for MA, with the prog- nosis being very good with complete cure from seizures in most cases.4-6 References 1. Bassoe P, Nuzum F. Report of a case of central and peripheral neurofibromatosis. J Nerv Ment Dis 1915; 42: 785-796. 2. Worcester-Drought C, Dickson WEC, McMenemey WH. Multiple meningeal and perineural tumours with analogous changes in the glia and ependyma (neurofibroblastomato- sis). Brain 1937; 60: 85-117. 3. Aizpuru RN, Quencer RM, Norenberg M, Altman N, Smirniotopoulos J. Meningioangiomatosis: clinical, radiologic and histopathologic correlation. Radiology 1991; 179: 819-821. 4. Ogilvy CS, Chapman PH, Gray M, De la Monte SM. Meningioangiomatosis in a patient with- out von Recklinghausens’s disease J Neurosurg 1989; 70: 483-485. 5. Harada K, Inagawa T, Nagasako R. A case of meningioangiomatosis without Von Reckling- hausen’s disease. Report of a case and a review of 13 cases. Childs Nerv Syst 1994; 10: 126-130. 6. Halper J, Scheithauer BW, Okazaki H, Laws EJ. Meningio-angiomatosis: A report of six cases with special reference to the occurrence of neu- rofibrillary tangles. J Neuropathol Exp Neurol 1986; 45: 426-446. 7. Rubenstein LJ. The malformative central ner- vous system lesions in the central and peripher- al forms of neurofibromatosis. A neuropatho- logical study of 22 cases. Ann NY Acad Sci 1986; 486: 14-29. 8. Partington CR, Graves VG, Hegstrand LR. Meningioangiomatosis. Am J Neuroradiol 1991; 12: 549-552 9. Kollias SS, Crone KR, Ball WJ, Prenger EC, Ballard ET. Meningioangiomatosis of the brain stem. Case report. J Neurosurg 1994; 80: 732- 735. 10. Tien RD, Osumi A, Oakes JW, Madden JF, Burger PC. Meningioangiomatosis: CT and MR findings. J Comput Assist Tomogr 1992; 16: 361-365.