Therapy‐associated effects in the prostate gland

Abstract

Diverse therapies are used to treat both benign prostatic hyperplasia and adenocarcinoma. Transurethral resection, a common surgical procedure, may give rise to characteristic necrobiotic granulomas that manifest in subsequent pathology samples. Radiation and hormone therapy have traditionally been used in prostatic adenocarcinoma. Morphological effects are often identified in needle biopsy specimens, transurethral resectates, and radical prostatectomy specimens. A range of histological changes are noted in the non-neoplastic prostate tissue, as well as in the pre-neoplastic and carcinomatous areas. Other ablative therapies, such as cryotherapy, and emerging focal therapies, including high-intensity focused ultrasound, photodynamic therapy, and interstitial laser thermotherapy, may have morphological effects on prostate tissue. It is important for the pathologist to be aware of the spectrum of histological changes affecting the prostate gland post-therapy. The treatment effects may obscure residual carcinoma, and make measurements of tumour extent and stage difficult. Furthermore, some therapies can profoundly alter the neoplastic glands to such an extent that Gleason scoring is no longer valid. As new therapies are developed for prostate cancer, it is important to document their effects on benign and malignant prostate tissue and to understand possible implications for traditional prognostic factors, especially Gleason grade.