Introduction: Seeding of biopsy needle tracks with viable malignant cells was an initial concern with all diagnostic breast needle procedures, including 14G automated needle biopsy. In an attempt to further evaluate this phenomenon, we have addressed the following questions: (1) are the tracks left by the needle biopsy procedure detectable in the surgical excision specimen? (2) Are displaced tumour cells visible along the needle tracks? (3) Is it possible to identify and excise the entire needle track for thorough histopathologic evaluation?
Methods: Surgical biopsy specimens of patients previously diagnosed with cancer on stereotactic 14G-needle biopsy were studied to find needle tracks. These are characterised by hemosiderin, scar tissue, foreign body giant cell reaction, fat necrosis, or organizing haemorrhage. Occurrence of displaced tumour cells or groups of cells along the tracks was registered.
Results: Needle tracks were found in 22/64 excision specimens of patients who underwent 14G-needle biopsy and surgery on the same day. Tumour-cell displacement along the needle track was seen in 11/22 cases (50%). In a prospective study, an attempt was made to excise the entire needle track in 13 consecutive cancer cases after 14G biopsy. Median time interval between core biopsy and first surgical excision was 21 days (range 7-35). Needle tracks could be visualised in 11/13 cases; displaced cells were seen in seven.
Conclusion: Needle tracks can be found in the excision specimens of patients who previously underwent 14G biopsy, and displaced tumour cells can be recognised. Excision of the entire needle track is neither feasible, nor advisable as a routine measure, since radiotherapy is advised for both in situ and invasive carcinoma after conservative surgery.