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

Objetivo: Estudio retrospectivo de la utilidad de la biopsia con aguja 14G de microcalcificaciones mamarias en lo que respecta a su valor para predecir benignidad. Material y métodos: Entre 1998 y 2001 se realizan 76 biopsias de microcalcificaciones con resultado de benignidad utilizando estereotaxia convencional, aguja automática 14G de largo recorrido, más de cinco cilindros, con comprobación radiológica (67%) e histológica (83%) de microcalcificaciones. No se incluyen lesiones de alto riesgo. Se clasifican los hallazgos en concordantes y no concordantes; ante discordancia se pautó biopsia escisional. Siempre, ante resultados inespecíficos, se pautó seguimiento. Se indicó la biopsia escisional en el seguimiento ante cambios mamográficos. Se realiza un seguimiento de al menos dos años y se efectúa la correlación histológica de los casos intervenidos. Resultados: 42 (55%) biopsias presentaron resultados inespecíficos. Se realizó biopsia escisional, por discordancia, en nueve (12%), con dos falsos negativos precoces (2,6%). Se controlaron 62 (81%), y el seguimiento fue incompleto en 14 (18%). En seis biopsias se evidenció un cambio mamográfico en la lesión (8%), el intervalo entre el diagnóstico inicial y los cambios osciló entre 6 y 35 meses, con una media de 22. No se evidenciaron falsos negativos tardíos. Conclusiones: La biopsia con aguja gruesa (BAG) de 14G condicionó un 55% de resultados histológicos inespecíficos, lo que obliga a seguir las lesiones con controles cortos; un 12% de biopsias por discordancia y un 2,6% de falsos negativos.

Aim: Retrospective study of the usefulness of 14G needle biopsy in predicting benignity of breast microcalcifications. Materials and Methods: Seventy-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. Results: Forty-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 mammographic change varied from 6 to 35 months, with the average being 22 months. No false negatives were observed after excisional biopsy. Conclusions: Thick 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.