Adult prostate sarcoma: radiological-clinical correlation.

AIM: To describe the imaging features and the correlation with clinical findings of adult prostate sarcoma. MATERIALS AND METHODS: Radiological data of seven adult male patients with prostate sarcoma, documented by pathological examination of specimens, were analysed retrospectively. Radiological features were correlated with clinical and pathological findings. RESULTS: The mean age of the study population was 45.8 years (range 21-76 years). The mean value of the serum prostate specific antigen (PSA) in seven patients was 1.59 ng/ml (range 0.735-3.72 ng/ml). Five patients had leiomyosarcomas and two had rhabdomyosarcomas. The most common symptom was urinary obstruction (n=7) and the most common sign was the markedly enlarged prostate as revealed by digital rectal examination (n=7). The mean size of the tumours was 8.7 x 7.2 x 7 cm (range 6.5 x 5x 6.5 to 12.1 x 10.2 x 8.9 cm). Tumours were round (n=4), lobular (n=2), or irregular (n=1). Two tumours occupied the majority of the prostate and five occupied the entire prostate. One tumour appeared as a homogeneous mass, and six tumours contained cystic areas on computed tomography (CT) and magnetic resonance imaging (MRI). Tumours enhanced avidly on contrast-enhanced CT (n=5) and MRI (n=2). Magnetic resonance spectroscopy (MRS; n=2) showed the ratio of choline:citrate to be 1.6 and 10.75. Tumour invasion was present in the bladder (n=3) and rectum (n=1). CONCLUSIONS: Adult prostate sarcoma was characteristically shown to be a large and heterogeneous mass with rapid, hypervascular and heterogeneous enhancement on CT and MRI. The main MRS feature was a marked increase in the choline:citrate ratio. The clinical manifestations corresponded mainly to local mass effects and tumour invasion.