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Bruce Lindquist,* a 79-year-old retired engineer, was having difficulty with double vision. He enjoyed building model airplanes but was finding it increasingly difficult to work with the small components. The diplopia had been bothering him for about two months, and his wife noted that his left eye had been “sticking out” for about the same period of time. As for other symptoms, Mr. Lindquist noted occasional moderate periocular pain when he looked up and to the left. In addition, he felt some numbness when he touched the top of his head.
We Get a Look
Mr. Lindquist consulted us when he was visiting his daughter, who lived in our area. When he described his symptoms, he denied experiencing any vision loss or having a history of trauma, and he reported no recent illnesses and no history of smoking. He also reported no previous ocular conditions other than the use of glasses.
Mr. Lindquist’s general medical history included an appendectomy and bilateral hernia repair. In addition, he had undergone treatment for prostate cancer, which was diagnosed 12 years earlier. The cancer treatment included drug therapy with leuprolide and flutamide; he also received external beam radiation therapy, which was administered in nine fractions.
Mr. Lindquist told us that he believed his disease was stable. He denied a family history of cancer but did note a history of glaucoma and retinal detachment in his mother.
Later, with encouragement, he disclosed that he had experienced a “tumor flare” of prostate cancer 15 months earlier. At that time, the results of a PET scan suggested metastatic disease in his lymph nodes.
Mr. Lindquist’s best-corrected vision was 20/40 in his right eye and 20/30 in his left. His IOP by applanation was 14 mmHg in both eyes. His pupils reacted 3+ with no afferent pupillary defect, and his visual fields were full by confrontation.
Extraocular movements were full in the right eye and showed significant restriction in the left: Mr. Lindquist had 10 percent motility on upgaze, 60 percent on downgaze, 25 percent on right gaze, and 50 percent on left gaze. Measurements by Hertel exophthalmometry were 22 mm in the right eye and 31 mm in the left with a base of 98 mm (Fig. 1).
The periocular examination demonstrated proptosis and eyelid retraction on the left, and it was notable for the absence of any eyelid swelling or conjunctival chemosis. Although the slit-lamp exam of the right eye was normal, that of the left eye revealed scattered punctate staining of the inferior one-third of the cornea as well as tortuous bulbar conjunctival vessels. There were 2+ nuclear sclerotic cataracts bilaterally. The dilated fundus exam showed a small epiretinal membrane in the right eye as well as mild venous tortuosity of the left eye with otherwise unremarkable fundi. Optic discs demonstrated 0.2 cupping in both eyes with mild hyperemia on the left. There was decreased sensation noted in the distribution of the supraorbital nerve on the left.
We ordered a hematologic workup that included a complete blood count, tests for thyroid function, and measurement of angiotensin-converting enzyme (ACE) and prostate-specific antigen (PSA) levels. In addition, orbital imaging was performed.
|(1) The patient’s diplopia, pain, and proptosis began two months before we first saw him. He also reported that he was experiencing some numbness when he touched the top of his head.
The Leading Suspects
Given the rapid onset of Mr. Lindquist’s symptoms, his description of his pain, and his history of prostate cancer, our leading suspect was an orbital metastasis.
Orbital metastases are rare in cancer patients, affecting 2 to 4 percent of cancer patients overall. Thus, other rapidly growing masses must be considered during the differential diagnosis and ruled out. These include orbital abscess, orbital varix, hemangiopericytoma, malignant fibrous histiocytoma, primary ocular melanoma, sarcoma, and orbital pseudotumor.
It should be noted that cavernous hemangioma, lymphangioma, and neural tumors—although they are more common orbital lesions—have a slower growth rate in general and didn’t fit our patient.
Results and Outcome
Although the results of the thyroid function and ACE tests were normal, Mr. Lindquist’s PSA level was markedly elevated. The orbital imaging found a large, superior, nonuniform retrobulbar mass (Figs. 2, 3), and an MRI of the chest and abdomen revealed diffuse nodal involvement.
Orbital metastases account for 1 to 13 percent of all reported orbital masses and generally present with proptosis or diplopia.1 Although most orbital metastases occur in patients with an established diagnosis of cancer, there may be no history of cancer in up to 25 percent of patients.1
|(2, 3) CONFIRMATION. A large, superior, nonuniform retrobulbar mass was evident on orbital imaging.
The leading causes of orbital metastatic disease are breast cancer, lung cancer, prostate cancer, and melanoma.1 Prostate cancer accounts for 3 to 10 percent of all orbital metastases and has a propensity to metastasize to bone tissue. For that reason, patients may complain of pain upon presentation.1 In contrast, women with breast cancer metastasis typically present with proptosis, motility defects, or enophthalmos, due to infiltration of extraocular muscles or orbital fat. (It should be noted that breast cancer accounts for most instances of orbital metastasis in women, with an incidence ranging from 28.5 to 58.8 percent of cases in several large studies.1)
Treatment of metastatic lesions in the orbit and ocular adnexa may include systemic chemotherapy, surgery, radiation, or hormonal therapy, singly or in combination.1
An orbital biopsy was considered for Mr. Lindquist. Ultimately, however, a biopsy was not pursued, given the inherent morbidity and high likelihood that the retrobulbar mass represented a metastasis of his recurrent prostate cancer.
Mr. Lindquist was restarted on leuprolide and flutamide and given emergent orbital radiation therapy, with close follow-up. Unfortunately, he died a few weeks later.
* Patient’s name is fictitious.
1 Ahmad SM, Esmaeli B. Curr Opin Ophthalmol. 2007;18(5):405-413.
Dr. Lowinger is an ophthalmology resident and Dr. Silkiss is chief of ophthalmic plastic, reconstructive, and orbital surgery; both are at California Pacific Medical Center in San Francisco. The authors report no financial interests.
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