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

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

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

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: