Risk of carcinoma after subsequent excision of benign papilloma initially diagnosed with an ultrasound (US)-guided 14-gauge core needle biopsy: a prospective observational study

To prospectively determine the upgrade rate following surgery in benign papilloma initially diagnosed at ultrasound (US)-guided 14-gauge gun biopsy. A total of 128 benign papillomas were diagnosed in 114 patients after a US-guided biopsy. Surgical excision was recommended where the biopsy indicated benign papilloma, regardless of imaging findings. The upgrade rate to 'atypical' and 'malignancy' was measured on a per-lesion basis. We analysed potential associations between clinical presentation, lesion variables and the results of surgical excision (using logistic regression). Of the 114 patients, 87 eventually underwent surgery: among the 100 supposed benign papillomas, surgical excision revealed fibrocystic change or no residual lesion in nine cases, intraductal papilloma in 74, atypical papilloma in 13, papillary ductal carcinoma in situ (DCIS) in three and one invasive papillary carcinoma. The upgrade rate for an atypical papilloma or papilloma with adjacent foci of atypical ductal hyperplasia (ADH) and malignancy was 13% (95% CI = 7.1-21.2%) and 4% (95% CI = 1.1-9.9%), respectively. The mean lesion size (P = 0.041) was significantly larger when lesions were upgraded to malignancy. Other features were not significantly associated with pathological underestimation (P > 0.05). Surgical excision should be considered for benign intraductal papillomas above 1.5 cm in size.