Determinants of success with spot localization biopsy of the breast

The accurate diagnosis of nonpalpable lesions of the breast by spot localization biopsy depends upon numerous variables.

Multivariate analysis was used to identify variables influencing the success of spot localization biopsy of 757 lesions (27.3 percent of which were malignant) in 738 patients.

Ninety percent of the lesions were removed with the first excision as documented by specimen radiography, but 2.3 percent (18 lesions) were not evident on specimen radiography with up to four excisional attempts. Eight (44 percent) of these 18 were in fact removed because they could not be seen on follow-up mammograms. Lesions with calcifications only were significantly more difficult to remove than were masses (87 compared with 96 percent, respectively, p < 0.001). The use of both hooked wire and methylene blue dye was significantly less successful than wire or dye alone (84 compared with 93 and 91 percent, respectively, p < 0.001). A second attempt was successful in 71 percent (52 lesions) of the remaining 75 percent lesions and additional attempts at excision were often associated with success. Success was highly variable among surgeons but could not be related to experience.

Calcifications are more difficult to remove than masses, and combining hooked wire with dye does not improve the success rate. Additional excisional attempts are worthwhile if the lesion is not seen on the first radiograph of the specimen.