Limitations of computed tomography following excisional biopsy of soft tissue sarcomas.

Twenty-one patients were evaluated by computed tomography (CT) following complete or incomplete excisional biopsy of soft tissue sarcomas. Since the surgical margins were inadequate, additional treatment was required, and CT was intended to identify and delineate any residual tumor. Thirteen patients had no palpable mass in the operative area. In these, eleven CTs showed no tumor, but microscopic tumor was found in seven. The other two CTs showed masses, but both proved to be hematomas. Eight patients had palpable masses and seven proved to be residual tumor. Of these, two CTs failed to show the residual tumor. Five CTs correctly identified residual tumor, but two of them failed to show the entire tumor extent. Computed tomography did not correctly predict the presence or absence of microscopic residual tumor when there was no palpable mass, and was at least partly inaccurate in delineating residual tumor in four of eight patients with palpable masses.