J.Neurol.Sci.[Turk] 1 Journal of Neurological Sciences [Turkish] 24:(2)# 11;75-79, 2007 http://www.jns.dergisi.org/text.php3?id=156 Case Report The Tip Of The Iceberg: Mediastinal Schwannoma Presenting As Horner’s Syndrome Afsun ŞAHİN 1 , Tulay KANSU 2 , E. Cumhur ŞENER 3 1 Eskisehir Osmangazi University Medical Faculty, Department of Ophthalmology, Eskisehir, Türkiye 2 Hacettepe University Medical School, Department of Neurology, Ankara, Türkiye 3 Hacettepe University Medical School, Department of Ophthalmology, Ankara, Türkiye Abstract A 43-year-old woman presented with a right-sided ptosis, miosis and facial anhidrosis. She was aware of her ptosis for the past year but did not seek for medical attention. Cocaine test was positive for Horner’s syndrome. A mass lesion was detected in the upper part of the posterior mediastinum. Surgical resection was performed and the histopathologic examination was compatible with a schwannoma. The most common tumors associated with Horner’s syndrome are lung (Pancoast) and breast cancers. Horner’s syndrome is not an early sign of these tumors. Mediastinal schwannoma has been reported in rare cases presented with Horner’s syndrome. Keywords: Horner's syndrome, schwannoma, mediastinum, magnetic resonance imaging Özet 43 yaşında bayan hasta sağ gözde pitozis, miyozis ve sağ yüz yarısında terlememe şikayeti ile başvurdu. Yaklaşık bir yıldır pitozisi mevcut olan hastanın hiç bir sağlık kurumuna başvurmadığı öğrenildi. Horner sendromu için yapılan kokain testi pozitif idi. Direkt akciğer grafisinde arka mediastinumun üst kısmında bir kitle lezyonu saptandı. Cerrahi olarak çıkarılan kitlenin hsitopatolojik incelemesi schwannoma ile uyumlu bulundu. Horner sendromu ile en sık birliktelik gösteren tümörler akciğer (pancoast) ve meme kanserleridir. Ancak Horner sendromu bu tümörlerin erken bir bulgusu değildir. Horner sendromlu olgularda mediastinal schwannoma ise nadir rapor edilmiştir. Anahtar Kelimeler: Horner sendromu, schwannoma, mediasten, manyetik rezonans inceleme INTRODUCTION Horner’s syndrome results from disruption of the sympathetic innervations to the eye and ocular adnexae. It occurs in anywhere along its three-neuron course. Classically the clinical triad includes ipsilateral ptosis, miosis and anhydrosis. Schwannomas, also known as neurilemmomas, are benign uncommon tumors arising from peripheral nerves in spinal root, acoustic nerve, the extremities, the body, trunk and neck. (1,2) They occur in any somatic or sympathetic nerve and characterized by solitary occurence, slow growth rate and smooth surface. Up to 45% of schwannomas occur in the head and neck region. (3) They have been associated with Horner’s syndrome in limited number of cases in the literature. (4- 6) To our knowledge mediastinal schwannoma has been reported in rare cases presented with Horner’s syndrome. (2,3) CASE PRESENTATION A 43-year-old woman presented with a right-sided ptosis, miosis and facial anhydrosis (Fig.1) She has been aware of her ptosis for the past year but did not seek for a medical attention. Her past history was unremarkable. On examination, her visual acuity was 20/20 in either eye. Ocular ductions and vergences were normal. She had anisocoria with the right