Metastasis of occult prostatic carcinoma to the sphenoid sinus: report of a rare case and a review of the literature.

We present a case (55-year-old) with a metastasis to the sphenoid sinus from an occult prostatic adenocarcinoma as the first evidence of disease. The patient's symptoms were progressive left-sided headache of a few months duration and a 2-week history of blurred vision with diplopia. Clinical examination revealed a left cranial nerve III palsy and ptosis. A computed tomography scan showed a 2 cm large, well delineated soft tissue lesion involving the left sphenoid sinus and extending to the left cavernous sinus with sclerosis of the adjacent sphenoid bone. Histological and immunohistochemical examinations revealed a poorly differentiated adenocarcinoma that was positive for prostate specific antigen (PSA) and broad-spectrum cytokeratins (Cam 5.2). Subsequent urological examination confirmed a locally advanced prostatic carcinoma with significantly increased serum-PSA (4,561 μg/l) and bone scintigraphy showed widespread metastasis.