Oculomotor Paresis: An Early Manifestation of Prostate Cancer.

A 57-year-old man with a benign medical history developed diplopia with left gaze for over a month prior to presentation. A neurological examination revealed signs of right oculomotor paresis, including ptosis; exotropia; anisocoria (the right pupillary size was fixed at 3.5 mm, while the left one was 2 mm in light and 4 mm in dark); and impaired adduction, elevation, and depression of the right eye (Picture A). No trigeminal nerve disorders were observed. Brain magnetic resonance imaging (MRI) showed a parasellar tumor extending into the right cavernous sinus (Picture B). Blood tests revealed elevated prostate-specific antigen (129 ng/mL, normal <4 ng/mL) and alkaline phosphatase (1,207 IU/L, normal <338 IU/L) levels. Bone scintigraphy showed multiple osteoblastic lesions in the skull base, thoracolumbar spine and pelvis (Picture C). Prostate needle biopsy revealed prostate adenocarcinoma (Picture D). The findings suggested right oculomotor paresis secondary to metastatic prostate cancer. Monthly injections of a gonadotropin-releasing-hormone antagonist, degarelix, were administered (240 mg initially, 80 mg/month thereafter). His symptoms resolved two days after the first injection, with no evidence of relapse 7 months later. Follow-up MRI revealed the near-absence of the parasellar tumor. Clinicians should consider ophthalmoplegia as a rare initial presentation of cavernous sinus lesions in patients with metastatic prostate adenocarcinoma (1,2).

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The authors state that they have no Conflict of Interest (COI).