Prostatic sarcoma after conservative treatment with brachytherapy for low-risk prostate cancer

The oncological history of the patient, a 71-year-old man, started 10 years before when he was diagnosed with organ-confi ned Gleason 6 prostate cancer. Serum prostate specifi c antigen (PSA) was 10 ng/ml. The patient was treated with interstitial permanent brachytherapy using I125 with a total dose planned of 145 Gy. PSA nadir of 0.1 ng/ml was achieved 38 months after treatment, and no urinary or digestive toxicity were observed. Urinary symptoms characterized by dysuria, nocturia, tenesmus and perineal pain started to appear nine years after brachytherapy treatment. Obstructive symptomatology rapidly evolved despite treatment with alpha-blockers for six months with substantial increase in nocturia and stranguria, as well as pelvic and lumbar pain, constipation and toxic syndrome. Digital rectal examination showed a large and heterogeneous prostate mass. Acute renal failure (creatinine of 393 μ mol/l) was detected in the blood test and PSA levels continued to be below the levels of detection. Abdominal computed tomography (CT) scan revealed bilateral grade III ureteral ectasia due to a large prostate with irregular contours. Thorax CT-scan did not fi nd lung dissemination. Transrectal ultrasound-guided biopsies and prostatic transurethral resection were performed. Prostate high-grade sarcoma with bladder extension was suspected and the patient underwent radical cystoprostatectomy with urinary derivation and extended pelvic lymphadenectomy. Gross pathological examination of the surgical specimen showed the prostate to be entirely replaced by grayish tumor tissue, which extended into the bladder wall (Figure 1A and B), surrounded the seminal vesicles and invaded the perivesical fat and both terminal ureters. Metastatic peritoneal nodules and bilateral pelvic lymph nodes were found as well. On histological examination, the tumor tissue ranged from bland myxoid areas with a heavy infl ammatory component to frankly malignant ones, made up of bundles of ovoid to spindle large atypical cells admixed with occasional lymphocytes and plasma cells (Figure 2). Mitoses and vascular invasion were easily found, and there were multiple foci of necrosis. On immunohistochemistry, the tumor cells were positive for vimentin and, focally, for cytokeratin AE1/AE3, CD68, and CD31, and negative for a number of other cytokeratins, EMA, muscle markers, CD21, CD23, CD30, CD34, CD117, S-100 protein, PSA and ALK-1. On the basis of these results, the tumor was classifi ed as a high-grade spindle cell sarcoma with features of infl ammatory myofi broblastic tumor. The patient had a torpid postsurgical evolution and died three months after surgery due to surgical complications and disease progression. Acta Oncologica, 2012; Early Online: 1–3