Columnar alteration with prominent snouts and secretions (CAPSS) is routinely described on breast core needle biopsies (CNBs); however, its significance and appropriate treatment is unknown. This study evaluated the incidence of cancer (in situ/invasive) in core biopsies and in subsequent surgical biopsy specimens after an initial core biopsy identifying CAPSS.

Using our medical center's pathology database, we retrospectively identified lesions described as CAPSS on breast core needle biopsies performed between January 1998 and August 2003. The specimens were subdivided into CAPSS lesions with and without atypical features. We also identified lesions described as atypical ductal hyperplasia.

Overall, 10 cancers were associated with 135 (7.4%) CAPSS lesions without atypia, and 11 (18.3%) were associated with 60 CAPSS lesions with atypia (P = 0.023). CAPSS lesions with atypical features had a slightly higher rate of coexisting cancer on initial biopsy than CAPSS without atypical features (7% vs 12%, P = 0.320). Specimens showing atypical ductal hyperplasia on initial biopsy had a greater rate of coexisting cancer than CAPSS with or without atypical features (P <0.0001).

We support the existing recommendation that a patient with a CNB showing CAPSS with atypical features undergo surgical biopsy.