Case study: A 55 y old woman presents with a cT2N0M0 triple negative breast cancer at our breast clinic. The upfront neo-adjuvant chemotherapy had to be interrupted due to clinically important needle tract metastasis (NTM), confirmed on imaging. Surgery was expedited and pathology report confirmed clear tumourload as NTM+. Aim:We conducted a literature study to evaluate the prevalence and prognostic importance for NTM+ after breast cancer diagnosis, treated with NACT. Moreover, the causal relationship between these NTM+ and the differences in puncture techniques was investigated. Conclusion:There seems to be a striking discordance between the (accidental) histopathologic diagnosis of NTM+ after surgery and prognosis. The malignant potential from these accidentally found NTM+ is not known, but seems not quite important, at least, when short interval between surgery and adjuvant radiotherapy is respected as defined in international guidelines. However, less is known about progression of these NTM+ during NACT and the consequences for local relapse and disease control at long term.Biopsy technique as such is reported as less important, but vacuum assisted biopsy seems to reduce the incidence of the described NTM+.