TUESDAY, Feb. 28 (HealthDay News) —— Breast lesions often deemed benign following a needle biopsy can still harbor adjacent cancers and should be removed anyway, U.S. researchers conclude.

　　"Our study shows that all papillary lesions of the breast should be surgically excised to avoid missing a cancer," study lead author Dr. Cecilia L. Mercado, an assistant professor of radiology at New York University Medical Center, said in a prepared statement.

　　Papillary lesions, which account for 1 percent to 3 percent of all lesions sampled by core needle biopsies, are benign growths in the duct of the breast. Current treatment for these lesions includes radiographic follow-up and surgical removal, depending on a doctor's recommendation.

　　While these lesions may be diagnosed as benign, they can harbor adjacent atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS) —— cancerous cells confined to the lining of the milk ducts. Left untreated, both these conditions put a woman at increased risk for future cancer.

　　For this study, the researchers analyzed the imaging and histologic outcomes of 42 patients diagnosed with benign papillary lesions after core needle biopsy. Doctors performed 43 biopsies on the 42 patients. Of the 43 biopsies, 36 (84 percent) of the lesions were surgically removed and seven (16 percent) received long-term imaging follow-up.

　　As a result of surgical removal of the lesion and laboratory follow-up, the diagnoses of nine of the 42 patients (21.4 percent) were upgraded to ADH or DCIS. That percentage is much higher than reported in previous research.

　　"This is one of the largest series and shows statistically significant findings. The results of our study revealed a considerable upgrade to either ADH or DCIS at core needle biopsy," Mercado said. "Therefore, all benign papillary lesions of the breast should be surgically excised, since a considerable number of atypical lesions and malignant lesions could be missed."