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A 71-year-old man presented to the emergency room (ER) with an acute, less than 24-hour, history of right periorbital edema, chemosis, and mild pain. His past medical history was significant for recurrent chronic myelogenous leukemia being treated with systemic chemotherapy. He recently had chemotherapy-related gastrointestinal bleeding for which he was given aminocaproic acid, which he was still taking at the time of presentation. One week prior the patient had a chemotherapy-induced acute increase in his platelet count from 9,000 to 618,000. A brain MRI ordered the day prior for headache was negative. In the ER, the patient was afebrile, and his white blood cell count was 34,000 with 10% blasts, a finding thought to be secondary to his leukemia. The patient denied history of trauma, infection, thyroid abnormality, or auditory bruit. On exam he was mildly somnolent. His visual acuity from the right eye was 20/200, and 20/25 from the left. He had a relative afferent pupillary defect on the right. His intraocular pressure was 35mmHg in the right eye. Ocular adnexal exam confirmed periorbital edema, chemosis, resistance to retropulsion, and ophthalmoplegia. There was no tenderness or warmth, and V1 and V2 sensory innervation were intact. Retinal exam was within normal limits. Orbital CT with contrast was obtained.

1.	The differential diagnosis includes all of the following, except:
	e -- pleomorphic adenoma of the lacrimal gland A through D can all cause an acute orbital presentation as in this patient. A pleomorphic adenoma typically causes a chronic, progressive inferonasal globe dystopia over the course of months to years. The constellation of clinical findings in this case including decreased vision to 20/200 and relative afferent pupillary defect would be unusual for a pleomorphic adenoma.
2.	The CT findings are consistent with which diagnosis?
	a -- superior ophthalmic vein thrombosis The CT shows a dilated right superior ophthalmic vein (SOV) that does not fill with contrast. The left SOV is of normal caliber and does fill with contrast. These imaging findings are consistent with either a SOV or cavernous sinus thrombosis.
3.	Likely etiologies for this patient's presentation include:
	c -- history of cancer, aminocaproic acid, and thrombocytosis This patient had a right SOV thrombosis. His hypercoagulability risk factors included cancer history, recent thrombocytosis, and taking aminocaproic acid.