Orbit and optic nerve
Inflammatory pseudotumor of orbit

Author: Nat Pernick, M.D. (see Authors page)

Revised: 15 May 2018, last major update February 2014

Copyright: (c) 2004-2018, PathologyOutlines.com, Inc.

PubMed Search: Inflammatory pseudotumor [title] orbit

Cite this page: Pernick, N. Orbit and optic nerve: inflammatory pseudotumor of orbit. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/eyeorbitinflammatorypseudo.html. Accessed December 17th, 2018.
Definition / general
  • May not be a specific disease process, but due to various causes (paranasal sinus tumors, Rosai-Dorfman disease, inflammatory fibrosclerosis, dysthyroid ophthalmopathy, cholesterol or keratin granulomas, traumatic fat necrosis, prior hemorrhage or abscess)
  • More common than infectious granulomas
  • Usually ages 20 - 49 years with good health and sudden onset of exophthalmos with variable lid or conjunctival edema
Case reports
  • Steroids (alleviate signs and symptoms)
  • Excision
Gross description
  • Indurated orbital mass, often surrounding optic nerve and enveloping extraocular muscles
Gross images

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Fibrotic mass surrounds the eye

Microscopic (histologic) description
  • General:
    • Edematous tissue with excessive production of ground substance, chronic inflammatory cells, vascular proliferation and hyperplastic connective tissue
    • May have periphlebitis with tissue eosinophilia
  • Inflammatory myofibroblastic tumor:
    • Combinations of fibroblasts and myofibroblasts in background of plasma cells and other inflammatory cells
  • Rosai-Dorfman related:
    • Large histiocytes, some with lymphocytophagocytosis, lymphocytes and plasma cells, often with prominent fibrosis
Whole mount images

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Dense fibrotic tissue
with focal lymphocytes
surrounds the eye

Microscopic (histologic) images

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Inflammation and
fibrosis involve the
orbital adipose tissue

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Chronic inflammatory
cells infiltrate an
extraocular muscle

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Vitreous tumor
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Tumor essentially
replacing vitreous cavity

Positive stains