Chronic lymphocytic leukemia presenting as unilateral extraocular muscle enlargement and proptosis.

Orbital involvement in chronic lymphocytic leukemia (CLL) is rare with very few published cases. We describe a case of unilateral isolated extraocular muscle enlargement in a patient with CLL. An incisional biopsy was performed from the left medial rectus muscle and histology revealed a lymphocytic infiltrate suggestive of CLL.