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

Abstract Background: Squamous cell carcinoma (SCC) of the prostate is a very rare and highly aggressive tumor, which is ineffective to multiple treatments and 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 hormonotherapy or radiotherapy. Hitherto, 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 presentation: A 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. Hormonotherapy 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. After treatment of 2 years, he complained of worsening of lower urinary tract symptoms(LUTS), and then he underwent transurethral resection of the prostate (TURP). Histological analysis revealed there were poorly differentiated keratinizing squamous cell carcinoma in the most of cancer tissue. As of now, the patient has undergone docetaxel treatment, containing 2 times of systemic chemotherapy. The patient's general condition is currently good.Conclusions: Prostatic adenocarcinoma transformed into squamous cell carcinoma after hormonotherapy 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, keratinization of histopathological examination enables its diagnosis. The transformation is subclinical. Hence, how to identify prostatic adenocarcinoma or SCC in prostate tissue needs a further investigation.