A Rare Case of Prostate Carcinoma Metastasis in the Orbital Apex

Prostate cancer (PC) is prone to bone metastases, but very rarely it can spread to soft tissues. In the head and neck region, PC can metastasize to the orbital soft tissue, causing various symptoms such as vision loss. In this report, we describe the case of a 79-year-old man with PC metastasis in the orbital apex. He presented to an ophthalmologist at our hospital with progressively worsening vision in his left eye over 3 to 4 months. He complained of a drooping eyelid in the same eye; thus, intracranial disease was suspected. Closer inspection with head computed tomography revealed a space-occupying lesion from the orbit to the posterior ethmoid sinus, and he was referred to our department. He had a history of PC, and we performed endoscopic sinus surgery for the diagnosis of malignancy, including metastasis of PC. As a result, the mass was diagnosed as PC metastasis by pathological examination. The patient began androgen blockade therapy and 3 months postoperatively, magnetic resonance imaging revealed that the extraconal orbital mass had decreased significantly. It is important to determine the metastases of PC in the paranasal region when the patient has a preexisting medical history.