Squamous cell carcinoma transformed from the prostatic adenocarcinoma with endocrine therapy: a case report and literature review

Background: Squamous cell carcinoma (SCC) of the prostate is a very rare and highly aggressive tumor, which is insensitive to multiple treatments, prone to metastasis, and has a worse prognosis than adenocarcinoma of the prostate. However, a transformation of prostatic adenocarcinoma into squamous cell carcinoma is rarer and may occur after endocrine or radiotherapy. By now, there are few cases in the world about the transformation from adenocarcinoma into squamous cell carcinoma after treatment. To our knowledge, our case is the first reported in China.Case presentationA 67-year-old man with metastatic adenocarcinoma of the prostate for 2 years, was not suitable for radical prostatectomy due to the disease classified T4N1M1. Endocrine therapy using Luteinizing Hormone-Releasing Hormone (LHRH) analog (leuprorelin) and antiandrogen agent (bicalutamide) was started, and serum prostate-specific antigen (PSA) level gradually decreased to a nadir of 0.04ng/ml. 2 years after treatment, he complained of worsening of lower urinary tract symptoms, and then he underwent transurethral resection of the prostate (TURP). Histopathological examination confirmed most of the tissue areas were accompanied by poorly differentiated keratinizing squamous cell carcinoma. Now, the patient started docetaxel treatment. He has received 2 times of systemic chemotherapy. The patient's current general condition is fair.ConclusionsProstatic adenocarcinoma transformed into squamous cell carcinoma after endocrine therapy is very rare. However, the serum PSA of this tumor is probably normal, PSA and the Gleason grading system are of limited value in the diagnosis of SCC, histopathological can help its diagnosis. The transformation is silent and we cannot know it. The question of whether prostatic adenocarcinoma or SCC of the prostate requires more definitive research to answer.