Risk factors associated with conversion from nonmalignant to malignant diagnosis after surgical excision of breast papillary lesions.

Purpose: Management of papillary lesions of the breast identified during preoperative tissue diagnosis remains controversial. This study was designed to analyze the clinical factors associated with under-diagnosis of malignancy in breast papillary lesions.

Methods: Patients with a preoperative tissue diagnosis of benign or atypical papillary lesions, who received surgical excision between 1991 and 2005, were identified. Age of diagnosis, family history of breast cancer, presentation of nipple discharge, palpable mass, mammogram grading, size of lesion, and final pathological diagnosis were analyzed. Tissue sections were reviewed to confirm the diagnosis of malignancy and reasons of discrepancy.

Results: A total of 205 women with 228 papillary lesions were studied. The median age was 42 (range, 12-83) years. Malignancies were diagnosed after surgery in 21 cases (9.2%). Patients aged 45 years or older and atypical lesions according to fine needle aspiration cytology (FNAC) or core needle biopsy (CNB) were associated with higher risk for postoperative malignant diagnosis with P values of 0.0008 and < 0.0001, respectively. Pathology review of 19 lesions with malignancy revealed that reasons for preoperative nonmalignant diagnosis were borderline lesions in nine (47.3%), sampling problem in six (31.5%), interpretation error in three (15.7%) and uninterpretable sample in one (5.2%).

Conclusions: In this cohort, 9.21% of preoperative nonmalignant papillary lesions were converted to malignant diagnosis after surgery. Atypical lesions and patients aged 45 years or older were significant factors associated with such conversion. Surgical excision should be considered for papillary lesions of breast, especially for patients with the identified risk factors.