Microcalcificaciones con diagnóstico de benignidad en biopsia con aguja gruesa (14G): seguimiento y falsos negativos en 76 casos

Abstract

AimRetrospective study of the usefulness of 14G needle biopsy in predicting benignity of breast microcalcifications. Materials and MethodsSeventy-six biopsies were performed between 1998 and 2001 on microcalcifications with benign diagnosis using conventional stereotactic, automated, large core (14 gauge) needle (more than 5 cylinders), with microcalcifications having been diagnosed radiologically (67%) and histologically (83%). There were included no high risk lesions.All findings were classified as either concordant or non-concordant. Non-concordant findings underwent subsequent exscisional biopsy. Follow-up was prescribed in cases of unspecific results. Excisional biopsy was indicated during follow-up should any mammographic changes have been observed.There were realized follow-up periods of at least 2 years. All cases were submitted to histological correlation. ResultsForty-two biopsies (55%) presented unspecific results. Excisional biopsy due to non-concordant results was performed in 9 cases (12%), with 2 false negatives (2.6%). Sixty-two cases (81%) were controlled, there being incomplete follow-up in 14 cases (58%).There were observed mammographic changes in lesions in 6 biopsies (8%). The time interval between initial diagnosis and mammo-graphic change varied from 6 to 35 months, with the average being 22 months. No false negatives were observed after excisional biopsy. ConclusionsThick needle biopsy (14 gauge) proved to be definitive in 55% of histologically unspecific results, which necessitated brief follow-ups. It also did so for 12% of those biopsies performed due to non-concordance and 2.6% of false negatives.Any changes occurring late in the follow-up period suggested the possibility of extending such beyond two years in order to establish benignity. The absence of late occurring false negatives, as previously published, related both to the size of biopsy samples and to the fact that a relatively high percentage of lesions were BI-RADS 3 classified.