Clinical value of transrectal ultrasound in the diagnosis of suspected neoplasia in the small pelvis

PURPOSE: In daily clinical practice, it is challenging to accurately diagnose suspected neoplasias in the small pelvis by minimal invasive means, and CT-guided biopsy is often limited in its feasibility. The aim of our study was to evaluate whether transrectal ultrasound (TRUS)-guided biopsy can verify suspected neoplasias in the small pelvis histologically. MATERIAL AND METHODS: The study population consisted of 12 patients who underwent biopsy of suspected malignancy in the pelvis by TRUS. All patients had clinical signs of an advanced tumour stage and in all cases, biopsy utilising computerised tomography (CT scan) had been unsuccessful despite of a documented lesion on CT scan or magnetic resonance imaging. For the TRUS guided biopsy, a commercially available 3-dimensional 7.5-MHz-probe was used (Combison 530 D, GENERAL ELECTRIC, Milwaukee, USA). The probe was armed with an 18 G biopsy gun. RESULTS: In all patients, the suspected lesion was easily detectable by TRUS, and tissue for verification of the malignant origin of the lesions could be collected under real-time TRUS with only 2 patients needing anaesthesia. The biopsy cores were of excellent quality and adequate for conclusive pathological diagnosis. 6 cases of lymph node metastases of a transitional cell carcinoma were detected. 1 case of extended node metastasis in prostate cancer, 1 paravesical manifestation of recurrent cervical cancer, 1 metastasis of a paravesically infiltrating colon cancer and 2 cases of paravesical metastases of a gastric cancer were also diagnosed. In one case, extragenital endometriosis could be diagnosed. CONCLUSION: Based on our experience it can be stated that TRUS-guided biopsy is a reliable diagnostic tool for verification of the neoplastic origin of suspected masses in the small pelvis. In all cases with a history of unsuccessful CT guided biopsy, sufficient tissue cores for conclusive histology could be collected with our technique, and surgical exploration could be avoided. This technique is minimally invasive, without radiation exposure, well tolerated under analgesia, time efficient and cheap.