Intraluminal ultrasound of rectal tumours: a prerequisite in decision making.

The use of intraluminal ultrasound (IUS) as a staging technique was evaluated in 58 patients with a rectal tumour. Thirty-four patients had a rectal carcinoma, four had a local recurrence after a previous anterior resection and 20 other patients had a villous adenoma. IUS assessment of rectal wall invasion, infiltration into adjacent organs, and the presence of perirectal lymph node involvement was compared with the definitive histological findings. In 90% of all patients the pre-operative local tumour staging was predicted correctly. In 38 patients with a rectal carcinoma the overall accuracy for the T grade was 84%. The sensitivity for the detection of perirectal fat infiltration was 91%, with a specificity of 70% and a negative predictive value of 78%. The accuracy in predicting direct infiltration into adjacent organs was 100% (n = 5). In the four patients with a local recurrence, the diagnosis was suspected by means of IUS and confirmed by biopsies. Extraluminal tumour growth was predicted correctly in all cases, with extension into the coccygeal bone in one patient. IUS identified lymph nodes in 29 of 38 cases, with a sensitivity of 57% and a specificity of 76%. All 20 villous adenomas were correctly staged as non-infiltrative tumours. After transmural excision, three adenomas proved to contain a completely removed T1 carcinoma. IUS is the most accurate tool in predicting the depth of local tumour invasion and needs a place in the preoperative screening programme in patients with a rectal tumour, as well as in the postoperative follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)