Eur. Radiol. 3,183-185 (1993)

© Springer-Verlag 1993

European Radiology

Neuroradiology Intradiploic epidermoid tumor of the occipital bone: X-RAY, CT, MR findings J. Pumar 1, E. Otero 1, A. Castifieira 1, M. Alvarez 1, L. Arrojo 1, M. Gelabert 2, J. Vidal 1 1Department of Radiology,Hospital General de Galicia, 15705 Santiago de Compostela, Spain 2 Department of Neurosurgery,Hospital General de Galicia, 15705 Santiago de Compostela, Spain

allows the precise dilineation of the anatomic boundaries of the tumor and establishes whether there is involvement of the rectus sinus, prior to surgery. Pathology confirmed the diagnosis of an epidermoid tumor.

Discussion Epidermoid tumors of the central nervous system are rare and constitute about 1% of all intracranial tumors [2]. They may affect any part of the skull: the scalp, the intra-

Case report A 13-year-old-girl had noted over the previous fortnight a tender lump in the occipital area. It had prevented her from sleeping on her back. Physical examination and laboratory data were normal. Plain skull X-rays (Fig. 1) revealed a round, doublecontoured, well-definedlytic lesion non-sclerotic margins adjacent to the occipital protruberance involving both the inner and outer tables. CT (Fig. 2 a) confirmed the presence of an occipital lesion.with an attenuation value higher than that of brain. Its origin was probably intradiploic and was expanding and eroding both the inner and outer tables. After contrast injection (Fig. 2b), a slight and uniform enhancenment was seen with no clear demarcation from the rectus sinus. M R demonstrated a moderately high-signal intensity lesion on a Tl-weighted sequence (Fig. 3 a), hyperintense on proton density (Fig. 3 b) and strongly hyperintense on T2-weighted images (Fig. 3 c). M R is very valuable as it Correspondence to: J. M. Pumar Cebreiro

Fig.1. Skull X-ray film: Towne's projection shows an osteolytic round area with well-defined non-sclerotic margins in the occipital bone

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Fig.2. a CT showing an intradiploic lesion that had eroded the outer and inner tables, b CT scan with contrast shows a slight and uniform enhancenment

cranial cavity and the diploe, involving either the inner table or outer one or both. Our case had evidence on Xray of bony destruction with a double, well-defined, nonsclerotic margin invading both the inner and outer tables. Though on CT these tumors are usually hypodense areas with no post-contrast e n h a n c e n m e n t [3] and on M R are seen as low-signal intensity tumors on T1, hyperintense on proton density and markedly hyperintense on T2 weighted sequences [4, 3], we have, in our case, as have others authors [5, 2] reported that the plain X-ray, CT and M R characteristics are variable and depend on the amount of cholesterol and keratin contained within. The X-rays findings were very suggestive of epidermoid tumor. CT and M R allowed us to define the margins, thus confirming that both tables were affected. M R established the absence of involvement of the rectus sinus. In conclusion, the diagnosis of intradiploic epidermoid cyst must be m a d e on X-ray; the differential diagnosis including histiocytosis X. M R and CT are needed when the characteristics are not specific or for presurgical evaluation.

Fig.3. a MR ha axial 500/25, TR/TE, b2000/25, TR/TE and c2000/110. Demonstrate the signal intensities of an epidermoid tumor

J. Pumar et al.: Intradiploic epidermoid tumor of the occipital bone

J. Pumar et al.: Intradiploic epidermoid tumor of the occipital bone

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1. Yanai Y, Tsuji R, Ohmori S, Tatara N, Kubota S, Nagashima C (1985). Malignant change in an intradiploic epidermoid: report of a case and review of the literature. Neurosurgery 16: 252-256. 2. Vion-Dury J, Vicentelli F, Jiddane M, Van Bunnen Y, Rumean C, Grisoli F, Salamon G (1987). MR imaging of epidermoid cyst. Neuroradiology 29: 333-338.

3. Olson J, Beck D, Cranford S, Menezes A (1987). Comparative evaluation of intracranial epidermoid tumors with computed tomography and magnetic resonance imaging. Neurosurgery 21: 357-360. 4. Demaerel Ph, Wilms G, Lammens M, Nutting BI Piers Ch, Baert AL, (1991). Extradural epidermoid tumor of the frontal bone. Neuroradiology 33: 349-351. 5. Rubin G, Scienza R, Pascualin A, Rosta L, Da Plan R. (1989) Craniocerebral epidermoids and dermoids. Acta Neurochir (Wien) 97: 1-16.

International Symposium on Chest Radiology Diagnosis and Intervention 17-19 March 1993; Lisbon, Portugal; Department of Radiology, Santa Marta Hospital

European Society for Magnetic Resonance in Medicine and Biology, ESMRMB 10th Annual Congress Rome, Italy, June 3~6, 1993

Director: Jo~o Martins Pisco, MD. Meeting place: Catholic University of Lisbon Honorary President: Jo~o Sim~es Raposo, MD. Programm Committee Chairman: Jo~o Martins Pisco, MD. Organizing Cornmittee: Isabel Nobre, MD. (General secretary), Otilia Fernandes, MD. (Treasurer), Isabel Basto, MD., Isabel Seixas, MD., Margarida Vilela, MD., Paula Petinga, MD. Information: Secretariat of International Symposium on Chest Radiology Diagnosis and Intervention (Isabel Nobre, M. D.); Servito de Radiologia, Hospital de Santa Marta Rua de Santa Marta, 1100 Lisboa, Portugal Tel. 53 28 55, Fax (3 51-1) 3 56 03 68

The Xth Congress of the European Society for Magnetic Resonance in Medicine and Biology will be held in Rome from 3-6 June 1993. The Congress will offer the participants best information on the latest developments and trends in MR imaging, spectroscopy, microscopy, and basic research. The scientificprogram will consist of four plenary sessions with internationally renowned speakers and more than 20 scientific sessions for special topics and free oral presentations. The Pre-Congress Teaching Program is divided into five contemporary courses dealing with: 1) state-of-the-art clinical MRI; 2) basic MRS; 3) fast imaging; 4) advanced concepts in MRI; 5) contrast enhancement. The four plenary sessions will concern: 1) current status of rapid imaging; 2) functional imaging; 3) MR spectroscopy; 4) MRI of cancer patients. Refresher courses are in the following subjects: 1) abdominal MRI 2) 3D MRI and image processing 3) new developments in hardware 4) musculo-skeletal MRI. Mini categorial courses will be based on MR angiography and cfinical neuro-MRI. English is the official language. Registration fees amount to £ 400.000 before 15 April 1993 and £ 500.000 thereafter (£ 300.000 and £ 400.000 for ESMRMB members). Teaching program fees amount to £ 80.000 before 15 April 1993 and £ 120.000'thereafter. A discount of 50 % is set for students and scientists from the eastern countries. Deadline for submission of abstracts for scientific sessions is 1 March (use the opposite form). The president of the congress is Prof. Roberto Passariello and the secretary is Dr. Paolo Pavone. For further information contact Organizing Office: Department of Radiology- University of Rome "La Sapienza" Policlinico Umberto 1-00161 Rome (Italy); Phone: 39-6-445 56 02 /4 46 85 87; Fax: 39-64902 43.

References

The third international congress RIPCV3: Percutaneous endovascular therapies 24-26 March 1993; Toulouse, France The honorary president will be Professor E. Zeitler. The program will include all percutaneous endovascular therapies, mainly percutaneous transluminal angioplasty (PTA) and new techniques. The selected topics are: Endoluminal therapies of aorto-iliac and femoro-popliteal artery complex lesions, Renal artery stenosis, Transjugular intra-hepatic porto-systemic shunts (TIPS), Endoluminal treatment of venous lesions, Endovascular imaging, Current concept of post-procedural intimal hyperplasia, Endoluminal treatment of acute arterial occlusions, Pulmonary embolism and venous thrombosis For further information, contact: Professeur F. Joffre, Department of Radiology, CHU RANGUEIL - Avenue J. Poulh6s, 31054 Toulouse cedex, Tel. (33) 6132 28 81, Fax: (33) 6132 24 92

Cours Cepur-Strasbourg CT of skull and spine:film reading session: 24-25 May 1993 MRI of skull and spine ERASMUS ( in english): 7-11 June 1993 Introduction to MRI of skull and spine (in french): 14-18 June 1993 Interventional CT (GRIS): 30 September-lst October 1993 Imaging of the digestive tract: 14-15 October 1993 CT of skull and spine: 13-17 September 1993 Information: Professeur Jean-Louis Dietemann, Service de Radiologie B, HSpitaux Universitaires de Strasbourg F-67091 Strasbourg cedex, France, Tel.: 88161195, Fax: 881612 80

European Society of Thoracic Imaging: Inaugural Meeting 13-15 June, 1993, Luxembourg, Hotel Intercontinental Main Topics: new developments in imaging; diffuse lung disease; immune related lung disease; thoracic vessels Council officers and programme committee: RArmstrong (GB), E Bernadac (F), L.Bonomo (I), J.Caceres (E), M.Coulomb (F), D.J.Delany (GB), R.F.Dondelinger (B), C.D.R.Flower (GB), J. Frija (F), G. R Gavelli (I),Pb. Grenier (F), D. Hahn (D), D. M. Hartsell (GB), C. J. Herold (A), B. Mayr (D), J. Remy (F), M. Remy-Jardin (F), E Schnyder (CH), J. R Senac (F), D. Tscholakoff (A), J. Verschakelen (B), R Vock (CH), G. Wegenius (S), A. G. Wilson (GB) Organizing committee: R.F. Dondelinger (B), P.A. Gevenois (B), J. Remy (F), J. Verschakelen (B) Information: Professor R.F.Dondelinger, Department of Medical Imaging, University Hospital Sart Tilman, 4000 Libge 1, Belgium, Tel. + 32 (0) 41/66 72 59, Fax + 32 (0) 41/66 7224