title: Orbital lymphoma masquerading as thyroid ophthalmopathy.
abstract: BACKGROUND
  Lymphoid tumors are known to originate within the lacrimal gland and orbital fat. Ocular findings commonly seen are a palpable mass with proptosis and downward displacement of the globe. Graves' ophthalmopathy is the most common orbital pathology occurring in the general population. Signs and symptoms of Graves' ophthalmopathy, such as unilateral or bilateral proptosis, double vision, limitation of movement of the extraocular muscles, are not specific for this condition.
  
  
  METHODS
  A 57-year-old man came to us with a chief symptom of "eye swelling" for the last 3 years. He had been diagnosed with hyperthyroidism and had received three surgical procedures for orbital decompression. Clinical findings included limitation of upward and downward gaze, exophthalmometry readings of 30 1/2 mm O.D. and 31 mm O.S. (with a base of 112), and profound proptosis with fatty tissue prolapse. Subsequent thyroid testing revealed euthyroid status and computed tomography scan revealed orbital lymphoma. Orbital involvement from a malignant nodular histiocytic lymphoma resulted in a proptosis similar to that observed in Graves' ophthalmopathy.
  
  
  CONCLUSIONS
  This very unusual presentation of orbital lymphoma mimicked Graves' disease so closely that the true cause was overlooked. This case emphasizes the need to include space-occupying lesions in the differential diagnosis of proptosis and gaze restrictions. The disease process and controversial management strategies are discussed.
authors.affiliation: Illinois Eye Institute, Illinois College of Optometry, Chicago, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Boyce
mesh_terms: D003131:Combined Modality Therapy; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D017809:Fatal Outcome; D006111:Graves Disease / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy; D009918:Orbital Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D014057:Tomography, X-Ray Computed