Bilateral enlargement of all extraocular muscles: a presenting ophthalmic sign of hematologic malignancy.

Hematologic malignancies such as leukemia and lymphoma can frequently present in the orbit; however, involvement of the extraocular muscles is rare. The authors report two cases of systemic hematologic malignancy presenting with bilateral extraocular muscle enlargement and associated compressive optic neuropathy (CON). Both patients experienced clinical and radiographic improvement of ocular and systemic manifestations of disease with prompt initiation of targeted chemotherapy. These cases highlight the importance of including hematologic malignancy in the differential diagnosis of atypical bilateral extraocular muscle enlargement.