Orbital Pseudotumors by MikeJenny

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									           Orbital Pseudotumor:
Idiopathic Orbital Inflammation
                           Shiva Kambhampati
MS4,George Washington University School of Medicine/
           University of North Carolina at Chapel Hill
Outline


 What is Orbital Pseudotumor?
 Differential Diagnosis
 Case Presentation
 Radiological Findings and Analysis
 Orbital Pseudotumor Subtypes
 Treatment
 Conclusions
What is Orbital Pseudotumor?
   First described in the 1900s
   AKA “Idiopathic Orbital Inflammation”, or
    “nonspecific Orbital Inflammatory Disease”
   Nonmalignant space occupying lesion involves orbital
    tissue and simulates a neoplasm
   Diagnosis of exclusion, based on patient history,
    clinical picture, response to steroids, and occasionally
    by biopsy
   Etiology unknown
   3rd most common cause of orbital inflammation
Differential Diagnosis of Orbital
Inflammation
    Inflammatory
        Thyroid Opthalmopathy
        Sarcoidosis
        Wegener’s
        Orbital Cellulitis
        Abscess
        Vasculitis
    Neoplastic
        Lymphoma
        Metastases
Clinical Presentation
  •Typically acute – but can be insidious
  •Painful
  •Usually unilateral
  •No real pattern of muscle involvement
  •Ocular findings include:
     •Diplopia
     •Decreased Visual Acuity
     •Proptosis
     •Edema
  •Absent systemic symptoms
Imaging Findings of Orbital Pseudotumor

   Imaging findings are characterized by inflammatory changes
    in orbital structures such as globe, lacrimal glands,
    extraocular muscles, orbital fat, and the optic nerve.

   MR findings:
       Isointense on T1
       Hypointense compared to normal muscle on T2
       Enhancement on post-contrast T1 images
Case Presentation
   62 y-o male dull ache in left eye and limited EOM
       PMH: uveitis


   Other Classical Clinical Presentations include:
       Eye pain
       Edema
       Proptosis
       Motility Restriction
       Ophthalmoplegia
       Lid Erythema
Case: Axial T1 Pre-Contrast




    Axial T1 image shows isointense infiltrative process in left eye involving
               the retro-ocular fat and external rectus muscle.
Case: Axial T2




     Axial T2 image shows the process to be mostly hypointense. Note
                                proptosis.
Case: Axial T1 Post-Contrast




     Post contrast T1 image shows the process to enhance and extend to
     ipsilateral cavernous sinus and along dura of left middle cranial fossa.
Orbital Pseudotumor Forms

    Dacryoadenitis
    Myositis
    Sclerosis
    Optic Nerve involvement
    Tolosa-Hunt Syndrome
    Intracranial extension
Differential Diagnosis of Orbital
Inflammation
   Inflammatory
       Thyroid Opthalmopathy
       Sarcoidosis
       Wegener’s
       Orbital Cellulitis
       Abscess
       Vasculitis


   Neoplastic
       Lymphoma
       Metastases
    Histology of Idiopathic Orbital Inflammation


   Fibrous connective tissue and scant perivascular
    patchy polyclonal lymphocytic infiltrates
Treatment
   Systemic Corticosteroids
       Usually rapid clinical response and resolution of pain


   Radiotherapy
       2nd line therapy
       Adjuvant treatment when incomplete response
       1st line therapy if steroids contraindicated

   Immunomodulators/Immunosuppresants
Conclusions
   Fairly common cause of orbital inflammation (3rd)
   Diagnosis of Exclusion, other causes must be ruled
    out
   Occasionally diagnosis by biopsy is performed
   Systemic Corticosteroids is primary treatment
   Rapid response to steroid treatment supports
    diagnosis of Orbital Pseudotumor
   MRI better imaging modality for characterizing
    intracranial extension
   Orbital Pseudotumor is not a lymphoid tumor
Etiology
   Etiology of Idiopathic Orbital Pseudotumor is unknown,
    but there are some theories in the literature
   Originally it was thought to be infectious in origin, with
    historical reports occurring after viral illnesses.
   Autoimmune pathogenesis was theorized because of a
    strong association with and rheumatologic diseases.
       Reports of circulating antibodies against extraocular muscle proteins
   IgG4 Related Systemic Disease
       Theory that links different inflammatory disorders that were
        previously thought to be unrelated
IgG4 Related Systemic Disease (IgG4-RSD)
   Systemic disease that is characterized by extensive IgG4-
    positive plasma cells and T-lymphocyte infiltration of
    various organs
   Pancreatitis, sclerosing cholangitis, cholecystitis,
    sialadenitis, retroperitoneal fibrosis, tubulointerstitial
    nephritis, interstitial pneumonia, prostatitis, inflammatory
    pseudotumor and lymphadenopathy, are all thought to be
    IgG4-related
       The prototype is IgG4-related sclerosing pancreatitis (also
        known as autoimmune pancreatitis)
   Disease usually responds well to steroid therapy
References
   Yuen SJ, Rubin PA. Idiopathic orbital inflammation: distribution,
    clinical features, and treatment outcome. Arch Ophthalmol
    2003;121:491-9.
   Lee et al. MR Imaging of Orbital Inflammatory Pseudotumors with
    Extraorbital Extension.
    Korean J Radiol. 2005 Apr-Jun; 6(2): 82–88.
   Bencherif B, Zouaoui A, Chedid G, Kujas M, Van Effenterre R,
    Marsault C. Intracranial extension of an idiopathic orbital
    inflammatory pseudotumor. AJNR Am J Neuroradiol. 1993;14:181–
    184.[PubMed]
   Weber AL, Romo LV, Sabates NR. Pseudotumor of the orbit. Clinical,
    pathologic, and radiologic evaluation. Radiol Clin North
    Am. 1999;37:151–168. [PubMed]
   Maksimovic O, Bethge WA, Pintoffl JP et-al. Marginal zone B-cell
    non-Hodgkin's lymphoma of mucosa-associated lymphoid tissue
    type: imaging findings. AJR Am J Roentgenol. 2008;191 (3): 921-30.
    doi:10.2214/AJR.07.2629
   Cheuk W. IgG4-related sclerosing disease: a critical appraisal of an
    evolving clinicopathologic entity. Advances in Anatomic Pathology.
    2010 Sep;17(5):303-32.

								
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