Is it necessary to biopsy the obvious?

OBJECTIVE. The radiologist and oncologist are often confident that biopsy w ill confirm their suspicion of recurrent disease, but a biopsy is performed to confirm the histologic diagnosis before beginning or altering therapy. We have examined data to determine how often the biopsied lesion represents recurrent disease from the primary tumor or is an instance of new cancer, and whether recurrent disease can he predicted. MATERIALS AND METHODS. We reviewed the medical and imaging records of 253 p atients who underwent CT-guided biopsy of an abdominal or pelvic lesion bet ween 1993 and 1996. Sixty-nine of the 253 patients had a previously diagnos ed primary tumor and were being examined for possible tumor recurrence or m etastasis, The images of these 69 patients were analyzed to determine if th e pattern of disease was typical of recurrence or metastasis. RESULTS. In 55 of the 69 patients, the pattern was judged to be typical of metastatic or recurrent disease. Biopsy confirmed this suspicion in all 55 patients. In 14 of the 69 patients, the pattern of spread was judged not to be typical of recurrence or metastasis. These 14 patients were found to ha ve a new primary tumor (n = 4), benign processes (n = 2), and recurrences ( n = 8). CONCLUSION. Of the patients for whom radiographic findings suggested recurr ence, we found no patients in whom a new primary tumor would have been miss ed if biopsy had been avoided. Data should now be acquired prospectively to determine whether it may be prudent to make treatment decisions on the bas is of imaging findings alone, without histologic confirmation.