Atypical papillary lesions after core needle biopsy and subsequent breast carcinoma

Background: Papillary lesions of the breast cause diagnostic problem because papillary structures are found in benign and malignant processes. Core needle biopsy is important to make an initial diagnosis, but it still has potential pitfalls. Comparison between core needle biopsy and excisional biopsy can predict the possibility of malignant change in atypical papillary lesions.

Objective: Evaluate the concordance between core needle biopsy and excisional results in atypical papillary lesions of the breast.

Materials and methods: The pathology database of University of Texas Medical Branch at Galveston, USA was searched for patients with atypical papillary lesions at core needle biopsy who subsequently underwent surgical excision. Pathology reports from the excisional biopsies was also examined to assign each case to one of three categories, downgrade to benign papilloma, no change (remained atypical papillary lesion), and upgrade to carcinoma. The mammograms and ultrasounds were reviewed for each case. They characterized the lesions according to multiple imaging criteria.

Results: Twenty-four patients with atypical papillomas at core biopsy subsequently underwent surgical excision. The lesions were downgraded to benign papilloma in 25%, remained atypical papillary lesion in 33%, and upgraded to carcinoma in 42%. On mammographic presentations (n = 23), masses were in 61%, architectural distortion in 4.3%, mass with calcifications in 9%, mass with architectural distortion and calcifications in 4.3%, calcifications alone in 17.4%, and architectural distortion and calcifications in 4.3%. On ultrasound findings (n = 21), solid masses were in 90%, intracystic masses in 10%, peripheral in locations in 81%, and subareolar in location in 19%.

Conclusion: Due to the high upgrade rate of atypical papillary lesions to carcinoma (42%), excision of all atypical papillary lesions with wide excision margin is recommended for cases with pathologic diagnosis of atypical papillary lesion on core-needle biopsy.