Clinical predictors of malignancy in patients diagnosed with atypical ductal hyperplasia on vacuum-assisted core needle biopsy

Introduction: Atypical ductal hyperplasia (ADH) is a benign lesion, which due to the risk of coexisting cancer is classified as a lesion of uncertain malignant potential. Aim: To identify clinical predictors of cancer underestimation in patients with ADH diagnosed after vacuum-assisted breast biopsy (VABB). Material and methods: Between 2001 and 2016, a total of 3804 vacuum-assisted core needle biopsies were performed at the First Chair of General Surgery of the Jagiellonian University Medical College in Krakow, including 2907 ultrasound (US)-guided biopsies and 897 digital stereotactic procedures. Seventy-six women were diagnosed with ADH and 72 of them underwent subsequent surgical excision. Demographic factors, medical history, family history, clinical symptoms, type and size of lesion determined in imaging scans, size of biopsy needle, and presence of coexisting lesions in VABB specimens were analysed as potential predictors of malignancy underestimation. Results: Underestimation of breast carcinoma occurred in 21 (29.2%) patients. The upgrade rate was significantly higher only in patients with a lesion visible both in mammography (MMG) and US examinations and combined BIRADS-5. Conclusions: Vacuum-assisted core needle biopsy is a minimally invasive technique used in diagnosing ADH. As the risk of breast malignancy underestimation is relatively high, open surgical biopsy remains the recommended procedure, especially in patients with lesions detected both in mammography and US examination. As we could not identify the factors that preclude cancer underestimation, all the women diagnosed with ADH should be informed about the risk of cancer underestimation.