Renal-Type Clear Cell Carcinoma of the Prostate: A Rare Case Report

Occurrence of clear cell carcinoma of the prostate is exceedingly rare and presents a diagnostic dilemma. We describe a case of a 47-year-old male nonsmoker, who presented with a history of frequency, dribbling urination, and dysuria for 6 months. In a digital rectal exam, enlarged prostate with a hard consistency was identified. All results for hematological and biochemical tests were normal. Also, the serum prostate-specific antigen (PSA) level was 2.7 ng/mL (within normal range). Open prostatectomy was done and the result showed a 300 g specimen, and a histopathological examination revealed clear cell carcinoma. A computerized tomography scan and ultrasound did not show any mass in the kidneys, but three nodules in both lungs in favor of metastasis were identified. Three months after surgery, a PET scan revealed hyperactivity in the abdominal wall, pelvic lymph nodes, and lung fields in favor of metastasis; thereafter, systemic therapy with tyrosine kinase inhibitor was prescribed. To the best of our knowledge, clear cell carcinoma of the prostate has been reported very rarely.