Orbital Tumors - Lymphoma

General

• almost exclusively in adults
• continuum including benign reactive lymphoid hyperplasia (pseudolymphoma) to atypical lymphoid hyperplasia to low-grade then high grade malignant lymphoma;
• also Orbital inflammatory syndrome pseudotumorplasmacytoma (including myeloma)
• bimodal peak 30’s and 60’s
• unilateral or bilateral
• palpable rubbery mass fixed to orbital rim
• maligant lymphoma & reactive lymphoid hyperplasia cause gradual (over a year or more) progressive, painless proptosis (vs. Obital inflammatory syndrome), lacrimal enlargement
• usually on conjunctiva, anterior orbit so palpable or visible
• eyelid or bilateral orbital involvement suggests systemic disease
• putty-like molding to undisplaced tissues so little Visual Acuity (VA) or EOM loss; usually no bone erosion or infiltration unless high-grade lymphoma
• lymphoma in retrobubar fat is infiltrative

Imaging

• all patients w/ orbital lymphoid lesions need exam for systemic lymphoma (by oncology) with orbital, abdominal, chest CT;
  • CBC
  • bone marrow biopsy
  • chest x-ray (CXR)
  • bone/liver/spleen scan

Pathology

• cytologic factors are more prognostic than mono/polyclonal; but
  • most benign lesions (reactive hyperplasia) are usually mostly T cells with polyclonal Bs;
  • malignant lymphoma usually more monoclonal B cells
• both polyclonal and monoclonal varieties can develop systemic disease
• open biopsy for path to give fresh tissue for touch preps; immunohistochemistry; flow cytometry; and gene rearrangement studies; in formalin for micro; gluteraldehyde for electron microscopy

Treatment & Course

• X-Ray Therapy (XRT) for most orbital lymphoid lesions that are confined to orbit (50% of lymphomas)
• Chemotherapy for systemic, therapy can be controversial
• Course
  • up to 25% of patients have systemic lymphoma later on with benign reactive hyperplasia:
  • 40% of patients get systemic involvlement within 5 years with atypical lymphoid hyperplasia: