Adult prostate sarcoma: radiological-clinical correlation

To describe the imaging features and the correlation with clinical findings of adult prostate sarcoma.

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.

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).

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.