Occult breast cancer: Where are we at?

Occult breast cancer (OBC) is described as an axillary metastatic carcinoma without detection of a primary breast lesion and is uncommon. Significant advances in breast imaging have occurred since its description, decreasing its incidence. However current management is based upon old studies, with variable clinical, radiological and pathological definitions of OBC. We suggest standardised definitions of OBC to facilitate more homogenous data representation in the literature. This review also discusses the conflicting heterogeneous data and its influence in determining the current management guidelines. We discuss whether the current significant surgical recommendations are necessary and postulate whether they could be safely substituted with less invasive management. •Pathological occult breast cancer is defined as no lesion detectable on MRI or pathological breast lesion post-surgery when examined at 5mm slices•NAC in OBC may result in the de-escalation of axillary surgery.•Current evidence indicates that ALND with ipsilateral breast RT has equivalent outcomes compared to ALND with mastectomy