Core needle biopsy. A useful adjunct to fine-needle aspiration in select patients with palpable breast lesions.

BACKGROUND: Fine-needle aspiration (FNA) biopsy is an established, highly accurate method for diagnosing palpable breast lesions. However, in some cases a definitive diagnosis cannot be made by FNA alone, either due to the inherent limitations of cytology itself or the ability to obtain adequate material for diagnosis. This study evaluated the usefulness of a supplemental core needle biopsy performed by a cytopathologist in conjunction with an FNA biopsy in select patients.

METHODS: Twelve patients with palpable breast lesions underwent the combined FNA/core needle biopsy procedure during the study period from March 1995 through March 1996. All 12 patients first had an FNA aspiration that was preliminarily evaluated by the FNA cytopathologist while the patient was at the clinic. If the cytopathologist was unable to render a definitive diagnosis of the lesion type or if a repeat FNA was requested by the clinician because of a previous non-definitive FNA result, a core needle biopsy was then performed.

RESULTS: When the FNA and the core needle biopsies were reviewed together, a correct definitive diagnosis was made in 10 of the 12 cases. In contrast, review of the FNA material alone yielded a correct definitive diagnosis in only five cases.

CONCLUSIONS: The supplemental core needle biopsy was found to be especially useful in: 1) providing a definitive diagnosis of infiltrating carcinoma in those cases in which the FNA diagnosis was reported as "suspicious;" 2) providing ample tissue for ancillary studies; and 3) differentiating a phyllodes tumor from a fibroadenoma. It is the authors' opinion that the FNA cytopathologist is the physician best qualified to perform the combined FNA/core needle biopsy procedure should he/she deem it necessary.