Fall 2017 Newsletter

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Fall 2017 Newsletter
7th Residency Announcement

Exciting Residency Announcement!

ACGME approves seventh resident complement; first increase in over 30 years!

Grand Rounds

Grand Rounds and Case Studies

Check out our weekly presentations



USC Ophthalmology Researchers Find More
Effective Treatments For Blinding Eye Diseases


Case Study: Hide and Seek

Danesh Kim
Presenter: Jennifer Danesh, MD Discussant: Jonathan Kim, MD


  • 54-year-old female with no significant past medical or ocular history presents with a nine month history of painless, worsening “foggy cloud” OS. Patient denied any history of trauma.

Exam Findings

  • Ocular Vitals
    • VA 20/20 OD, 20/80 PH 20/50 OS
    • IOP 14 OD, 13 OS
    • Pupils: 3→2mm OD, 8mm and nonreactive OS. 2+ rAPD OS
  • Slit lamp exam OU
    • Notable for relative proptosis and resistance to retropulsion OS
    • Hertel 13mm OD, 17mm OS
  • Dilated Fundus Exam OU
    • Optic nerve with mild temporal pallor OS, otherwise unremarkable
  • CT Scan
  • Figure 1
    Figure 1: Axial CT remarkable for a large, well defined, ovoid space occupying mass in the left retrobulbar area, extending anteriorly towards the globe and posteriorly towards the apex. Lesion is homogeneous in composition and isodense to adjacent muscle bellies.
    Figure 2
    Figure 2: Coronal CT illustrating the marked compressive effect on surrounding orbital structures.

    Differential Diagnosis of Acquired Unilateral Orbital Mass

    • Vascular
      • Cavernous hemangioma (most common benign orbital neoplasm)/li>
      • Hemangiopericytoma/li>
      • Lymphangioma aka Lymphatic Malformation/li>
      • Venous Malformation (i.e. orbital varices)
      • AVM
      • AV Fistula
    • Neural Tumors
      • Neurofibroma, Meningioma, Schwannoma, Glioma
    • Mesenchymal
      • Fibrous histiocytoma, solitary fibrous tumor, fibrous dysplasia, osteoma, dermoid cyst, dermolipoma
      • Malignant(rare): Rhabdomyosarcoma, Liposarcoma, Fibrosarcoma, Chondrosarcoma, Osteosarcoma
    • Malignancy
      • Lymphoma, Invasive sinus (SCC, AdenoCa) or intracranial process, other metastatic disease (most commonly breast and lung)

    Additional Investigations

    • Patient underwent lateral orbitotomy with bone flap and excision of lesion
    Figure 3
    Figure 3: H&E tissue stain remarkable for dense cellular areas with compact spindle cells and palisading nuclei surrounding acellular pink areas. Pattern consistent with verocay bodies in an Antoni A pattern.
    Figure 4
    Figure 4: Antoni A and Antoni B patterns with markedly positive S100 staining.


    • Orbital Schwannoma


    • Rare, slow growing, encapsulated (by perineurium) tumor arising from the nerve sheath fascicle of either motor or sensory nerves
      • Very rare, accounting for 1% of all tumors in the orbit
    • Arises from hyperplasia of myelin producing schwann cellst
      • Occurs in isolation, or as part of syndromes such as NF-2, Schwannomatosis, and less commonly NF-1
    • Most originate from branches of CN 3,4,5,6, parasympathetics, or sympathetics
      • Theoretically cannot occur in CN 1 or 2 because these lack sheaths composed of schwann cells


    • Surgical excision
      • Prevent compression of optic nerve and surrounding or involved cranial nerves
      • Incomplete removal can lead to recurrence or intracranial extension
    • Decompression
      • If resection not possible (i.e. apical tumors)
    • Radiation Therapy
      • Risk of optic neuropathy, secondary malignancy


    • Typically good prognosis with improved VA
    • Must monitor for recurrence, malignant transformation
    • Recurrence has been noted from days to many years after excision
      • Residual or de novo

    Deep orbitotomy: Surgical incisions

    • Hidden approaches
      • Upper lid crease incision
      • Caruncular approach
      • Conjunctival fornix approach
      • Conjunctival peritomy approach
      • Lateral canthotomy
    • Others:
      • Upper lid split
      • Lynch incision
      • Brow incision
      • Kronlein incision

    Deep orbitotomy: preferred techniques

    • Subperiosteal approach*
      • Periosteal release at the lateral canthus
    • Bone contouring at the orbital rim (near lacrimal fossa)
    • Bone flaps
    • Bone flap + bone contouring*
    • Retractors (e.g lonestar)*
    • Neurosurgical cottonoids*
    • Finger palpation*
    • Suture traction on orbital mases*
    • Cryotherapy probe*
    • Medial/lateral combined approach
    • Combined neurosurgical approach
    • Navigation systems

    Deep orbitotomy tips:

    • Prepare for the worst: obtain as wide an approach as possible
    • Study the anatomy then visualize the relationships
    • No cautery in the deep orbit
    • Keep fat out of your field as long as possible (subperiosteal approach)
    • Have an experienced assistant
    • Visualization requires patience


    • Daras M, Koppel BS, Heise CW, Mazzeo MJ, Poon TP, Duffy KR. Multiple spinal intradural schwannomas in the absence of von Recklinghausen’s disease. Spine (Phila Pa 1976)
    • Koktekir BE, Kim HJ, Geske M, Bloomer M, Vagefi R, Kersten RC. Orbital schwannomatosis in the absence of neurofibromatosis. J Craniofac Surg. 2014;25(6):2109-11.
    • Delfini R, Missori P, Tarantino R, Ciapetta P, Cantore Surg Neurol. 1996 Feb; 45(2):147-53; discussion 153-4.
    • Nagashima H, Yamamoto K, Kawamura A, Nagashima T, Nomura K, Yoshida M. Pediatric orbital schwannoma originating from the oculomotor nerve. J Neurosurg Pediatr. 2012;9(2):165-8.
    • Kim MS, Park K, Kim JH, Kim YD, Lee JI. Gamma knife radiosurgery for orbital tumors. Clin Neurol Neurosurg. 2008;110(10):1003-7
    • Delfini R, Missori P, Tarantino R, Ciapetta P, Cantore G. Primary benign tumors of the orbital cavity: comparative data in a series of patients with optic nerve glioma, sheath meningioma, or neurinoma. Surg Neurol. 1996;45(2):147-53.
    • Brucoli M, Giarda M, Arcuri F, Benech A. A benign isolated schwannoma of the orbit. J Craniofac Surg. 2011;22(6):2372-4.
    • Konrad EA, Thiel HJ. Schwannoma of the Orbit. Ophthalmolgica, Basel; 1988. p. 118-27
    • Goh AS, Kim YD, Woo KI, Lee JI. Benign orbital apex tumors treated with multisession gamma knife radiosurgery. Ophthalmology. 2013;120(3):635-41.
    • Kron M, Bohnsack BL, Archer SM, Mchugh JB, Kahana A. Recurrent orbital schwannomas: clinical course and histopathologic correlation. BMC Ophthalmol. 2012;12:44.
    • Khan SN, Sepahdari AR. Orbital masses: CT and MRI of common vascular lesions, benign tumors, and malignancies. Saudi J Ophthalmol. 2012;26(4):373-83.
    • Shields JA, Bakewell B, Augsburger JJ, Flanagan JC. Classification and incidence of space-occupying lesions of the orbit. A survey of 645 biopsies. Arch Ophthalmol. 1984;102(11):1606-11.
    • Kauser H, Rashid O, Anwar W, Khan S. Orbital oculomotor nerve schwannoma extending to the cavernous sinus: a rare cause of proptosis. J Ophthalmic Vis Res. 2014;9(4):514-6.
    • Kim KS, Jung JW, Yoon KC, Kwon YJ, Hwang JH, Lee SY. Schwannoma of the Orbit. Arch Craniofac Surg. 2015;16(2):67-72.
    • Yulek F, Demer JL. Isolated schwannoma involving extraocular muscles. J AAPOS. 2016;20(4):343-7.Tezer MS, Ozcan M, Han O, Unal A, Ozlugedik S. Schwannoma originating from the infraorbital nerve: a case report. Auris Nasus Larynx. 2006;33:343–345.
    • Konrad EA, Thiel HJ. Schwannoma of the orbit. Ophthalmologica. 1984;188:118–127
    • Ribeiro SFT, Queirós T, Amorim JM, Ferreira AM, Sales-sanz M. An Unusual Differential Diagnosis of Orbital Cavernous Hemangioma: Ancient Schwannoma. Case Rep Ophthalmol. 2017;8(2):294-300.


    Section Editors


    Produced by: Monica Chavez, John Daniel, Dr. Vivek Patel and Mellissa Linton
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