| OCR Text |
Show ]. Clin. Neuro-ophthalmol. 2: 197-199, 1982. Orbital Echinococcosis Report of Two Cases Studied by Computerized Tomography ZAFER KARS, M.D. TULAY KANSU, M.D. OSMAN E. OZCAN, M.D. AYKUT ERBENGI, M.D. Abstract Two cases of orbital echinococcus cysts studied by computed tomography are presented. Incidence of orbital hydatidosis in Turkey is reported. Computed tomographic findings of orbital hydatid cysts are reviewed and summarized. Medial displacement of the orbital plate of the ethmoid bone is emphasized as a frequent finding in the reported cases. Orbital echinococcus cysts are considered among rare causes of unilateral proptosis. This entity is unusual even in countries where echinococcosis is endemic. Two cases investigated and treated at the Department of Neurosurgery, Hacettepe University Faculty of Medicine, Ankara, are presented. These cases were subjected to computed tomography (CT) that revealed retrobulbar cystic tumors. Final diagnosis was made by operative and histological findings. Case Reports Case 1 A 7-year-old boy was admitted with progressive left-sided proptosis of 7-months duration. Physical examination, chest, and skull x-rays were normal. Neuro-ophthalmological examination revealed left-sided exophthalmos of 5 mm and papilledema. Vision was slightly decreased on the left (20/30) and ocular movements were intact. The eyeball was nonpulsatile and nonreducible. CT scan revealed a well-defined cystic tumor in the left orbit situated posterior and medial to the eyeball. The optic nerve was not seen. Medial wall of the orbit was displaced towards the nasal cavity by the tumor. Density of the cyst was similar to that of water or cerebrospinal fluid (CSF) (Fig. 1). From the Departments of Neurosurgery and Neurology (Neuroophthalmology Unit), Hacettepe University Faculty of Medi· cine, Ankara, Turkey. September 1982 Figure 1. Left intraorbital hydatid cyst. Rupture of orbital plate of ethmoid bone (colse I), The left orbit was explored through a transcranial approach on August 31, 1977. An echinococcus cyst containing approximately 8 ml of hydatidic fluid, located at the posteromedial aspect of the orbit was removed. Histological findings confirmed the operative diagnosis. The patient was readmitted 2 years later because of recurrent left-sided proptosis. Neuro-ophthalmological findings suggested an expanding lesion of the left orbit. A repeat CT scan again showed a cystic tumor in the left orbit located posterior to the eyeball (Fig. 2). A left-sided transcranial orbitotomy was performed on November 12, 1979, and it recurrent echinococcus cyst was removed totally. 197 Orbit,ll Echinococcosis Figure 2. Orbital sections showing recurrence of hydatid cyst in posteromedial location of the left orbit (case 1). Control examination performed a 2 years after the second operation was completely normal. Case 2 An ll-year-old girl was admitted because of progressive right-sided proptosis of 14-months duration. Physical examination, chest, and skull x-rays were normal. Neuro-ophthalmological examination revealed right-sided proptosis of 12 mm and papilledema. Vision was slightly disturbed on the right (20/30). Upward, medial, and lateral ocular movements were limited on the right. The eyeball was non pulsatile and nonreducible. CT scan showed a well-defined round cystic tumor in the right orbit located posteromedial to the eyeball. The optic nerve was not visible. The medial wall of the orbit was displaced towards the nasal cavity by the tumor. Densimetric evaluation of the cyst led to values similar to those of water or CSF (Fig. 3). The right orbit was explored through a transcranial approach on August 28, 1980. An echinococcus cyst containing approximately 12 ml of hydatidic fluid, situated medial to the muscular cone was removed totally. Histological findings were in accordance with the operative di<1gnosis. Control ex< 1mination performed 6 months ,lfter the operation rl'w,lled slight ptosis and an exophthalmos of .\ 111111 "n IllI' nght. Vision was intact. Figure 3. Right intraorbital hydatid cyst located posteromedially and extending to the nasal cavity with erosion of the medial orbital wall (case 2). Discussion Orbital echinococcus cyst is considered to be an unusual cause of unilateral proptosis. Incidences of 13.6%, 6.0%, and 19.8% (of all orbital tumors) are reported from Spain, I lebanon/ and Iraq,S respectively. In a review of 335 cases of echinococcosis from Turkey;' orbital echinococcosis was not encountered. Two cases of orbital echinococcus cysts presented above constitute 6.6% of 30 orbital tumors operated in our institution in the last 10 years. It is accepted that cr has offered a definite solution to the diagnostic problems met in the investigation of intracranial and orbital echinococcus cysts.~ The first case of an orbital hydatid cyst studied by cr was reported by Ozgen et al.7 Subsequent cases subjected to cr were reported by Amaya et aI., I Danziger and Price,3 Hamza et ,ll.,~ liegl et al.,° and Toledo and Szelagowski.9 Our findings and previously reported cases define the CT image of an orbital echinococcus cyst as a well-defined round cystic mass of which central densimetric value is similar to that of water or CSF. At the periphery this value may reach to that of normal cerebral tissue or slightly higher. Increase in the peripheral density after the injection or contrast medium is also reported. I. 4 Displacement and/or rupture of the medial wall of the orbit into the nasal cavity is a frequent feature that deserves special mention.3. 4 Journal of Clinical Neuro-ophthalmology The authors conclude that echinococcus cysts must be considered in the differential diagnosis of cystic and encapsulated orbital tumors disclosed by CT, especially in countries where the disease is endemic. References 1. Amaya, C, Yillarejo, F., Izquierdo, ).M., Pen,z-Higueras, A., and Blazquez, M.G.: Hyd,ltid cyst: Unusual cause of unilateral exophth.llmos. Surg. Neuw/. 14: 351-354, 1980. Z. Baghsassarian, S.A., and Zakh.ui.l, H.: Report of three cases of hydatid cyst of the orbit. Am. f. Ophthalmol. 71: 1081-1084, 1971. 3. Danziger, A., and Price, H.: Computed tomographic findings in orbital echinococciasis. ]. Compo Assist. Tomogr. 4: 128-129, 1980. 4. Hamza, R., Touibi, 5., Jamoussi, M., Bardi-Bellagha, I.. and Chtioui, R.: Intracranial and orbital hydatid September 1982 Kars, Kansu, Ozcan, Erbengi cysts. Neuroradiology 22: 211-214, 1982. 5. Kaya, U., Ozden, B., Ti.irker, K., and Tarcan, B.: Intracranial hydatid cysts. Study of 17 cases. ]. Neurosurg. 42: 580-584, 1975. 6. Liegl, 0., Werner, K., and )anitschke, K.: Echinokokkus- Zyste in der Orbita. Klin. Monatsbl. Augenhei/ kd. 177: 80-84, 1980. 7. Ozgen, T., Erbengi, A., Bertan, Y., Saglam, 5., Gi.ir\, ay, 0., and Pirnar, T.: The use of computerized tomography in the diagnosis of cerebral hydatid cysts. f. Neurosurg. 50: 339-342, 1979. 8. Talib, H.: Orbital hydatid disease in Iraq. Br. f. Surg. 59: 391-394, 1972. 9. Toledo, E.CG., and Szelagowski, J.C: Unilateral exophthalmos in orbital echinococciasis. f. Camp. Assist. Tomogr. 4: 127, 1980. Write for reprints to: Aykut Erbengi, M.D., Hacettepe University Faculty of Medicine, Department of Neurosurgery, Ankara, Turkey. 199 [CLorbitalinfections] |
