624 A rare cause of proptosis—Kukreja et al. Neuroblastoma-like schwannoma as a rare cause of proptosis: a case report Manu Kukreja, MD; Ritesh Gupta, MD; Anurag Julka, MD; M.C. Sharma, MD ABSTRACT • RÉSUMÉ Case report: We report a rare case of a unique variant of schwannoma (neuroblastoma-like schwannoma) in the orbit in a 16-year-old male who presented with proptosis and decreased vision. Comment: Schwannoma with giant rosettes and hyperchromatic small cells was previously designated a neuroblastoma-like schwannoma by Goldblum et al. (Am J Surg Pathol 1994;18[3]:266–73). In the past, 9 cases of this variant of schwannoma have been reported as a painless subcutaneous nodule in various parts of the body, but none has been reported in the orbit so far. This entity must be distinguished from neuroblastoma, neuroectodermal tumor, and malignant change in schwannoma. Observations : Présentation d’un rare cas de variante unique de schwannome, le schwannome semblable au neuroblastome, dans l’orbite d’un garçon de 16 ans qui s’était présenté avec une proptose et une vision affaiblie. Commentaires : Le schwannome, avec rosettes géantes et petites cellules hyperchromatiques, s’appelait auparavant schwannome semblable au neuroblastome, vocable que lui avaient donné Goldblum et al. (Am J Surg Pathol 1994;18[3]:266–73). Dans le passé, on avait signalé 9 cas de cette variante du schwannome décrite comme étant un nodule sous-cutané et indolore dans diverses parties du corps, mais on n’en avait mentionné aucun dans l’orbite de l’œil jusqu’ici. Il faut distinguer cette entité d’avec le neuroblastome, la tumeur neuroectodermique et la forme maligne du schwannome. O rbital schwannomas are rare and account for 1%–6% of all orbital tumors. A number of variants of schwannoma have been described, including “ancient” schwannoma, plexiform schwannoma, 1 schwannoma with glandular elements, 2,3 epitheloid schwannoma, 4 and neuroblastoma-like schwannoma. 5–8 Neuroblastoma-like schwannoma may mimic neuroblastoma or neuroectoder- mal tumors. To the best of our knowledge, we are reporting a rare case of neuroblastoma-like schwannoma in the orbit for the first time along with a review of the literature empha- sizing the differential diagnosis. CASE REPORT A 16-year-old male presented with painless, progressive axial proptosis associated with loss of vision of the left eye for the previous 6 months. Local examination revealed noncompressible and nonreducible proptosis (5 mm) of the left eye. Visual acuity was 20/20 in the right eye and 20/400 in the left eye. There was relative afferent pupillary defect in the left eye. There was mild global restriction of movements. Computed tomography scan revealed an intraconal, well-circumscribed, homogenous, elongated ovoid mass measuring 22 × 20 mm in size, displacing the optic nerve temporally and the medial rectus muscle medially (Fig. 1). The presumptive diagnosis of orbital hemangioma, meningioma, or schwannoma was made, and orbitotomy with tumor excision was performed. Biopsy revealed the diagnosis of neuroblastoma-like schwannoma. After surgery the proptosis was reduced, and 4 weeks later the patient’s vision had improved to 20/200 in the left eye; it remained stable after that. He was doing well without any recurrence or metastasis at 1 year follow-up. From the All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India Originally received May 11, 2006. Revised Feb. 22, 2007 Accepted for publication May 4, 2007 Published online July 17, 2007 Correspondence to: M.C. Sharma, MD, Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India; sharmamehar@yahoo.co.in This article has been peer-reviewed. Cet article a été évalué par les pairs. Can J Ophthalmol 2007;42:624–5 doi: 10.3129/can j ophthalmol.i07-106 Fig. 1—Computed tomography scan of the orbit axial section showing an intraconal, well-circum- scribed, homogenous, elongated ovoid mass meas- uring 22 × 20 mm in size, displacing the optic nerve temporally and the medial rectus muscle medially. ..