Wk 1, Case 4 - Review

Patient History
Blurred vision.

Findings
There are bilateral enhancing lesions involving both orbits. There is a large enhancing left retrobulbar mass that abuts the posterior aspect of the sclera. This diffusely enhancing mass surrounds the left optic nerve and peripherally displaces the medial and inferior rectus muscles. The mass extends inferiorly and encases the left inferior rectus muscle. There does appear to be some thickening involving the left eyelid.

There is also a diffuse enhancing lesion involving the right orbit. This diffusely enhancing masses involves the retrobulbar region and extends medially to involve the medial rectus muscle. The mass extends superiorly and encases the superior rectus and superior oblique muscles. There is retrobulbar extension of the mass. The lesion abuts the superior aspect of the right optic nerve but does not have the degree of encasement of the left optic nerve as seen on the contralateral side.

The above abnormality has increased DWI signal associated with reduced ADC suggestive of a densely cellular and possibly malignant process.

No abnormal sellar or juxtasellar enhancing lesions are seen. No evidence of compressive lesions are identified involving the optic chiasm. No abnormal lesions are identified involving the anterior skull base or olfactory sulcus. The bilateral gyrus rectus are normal. No evidence of aggressive skull base lesions are seen. No abnormal enhancing lesions are identified in the region of the perimesencephalic cistern. The fat in the bilateral pterygopalatine fossa is symmetric and within normal limits. No definite evidence of aggressive lesions are identified within either cavernous sinus or Meckel's cave.

Conclusions
1. Diffuse bilateral enhancing orbital masses associated with increased DWI signal and reduced ADC. These findings are most consistent with lymphoma. Another differential consideration is IgG4 associated disease. This patient does not have the clinical symptoms that would suggest orbital pseudotumor. There is no history of malignancy which makes metastasis unlikely.
2. No evidence of abnormal enhancing lesions involving either Meckel's cave.