Immediate postoperative mammogram for failed surgical excision of breast lesions In a series of 200 consecutive preoperative needle localizations of non-palpable breast lesions, 128 lesions (64%) were calcified and 72 lesions (36%) were noncalcified on preoperative mammograms. Radiographs of the surgical specimen failed to confirm excision of 11 lesions (5.5%), seven calcified and four noncalcified. These 11 patients were taken directly from the surgical suite to the radiology suite, where an immediate postoperative mammogram was obtained. In five patients (2.5%), immediate postoperative mammograms showed surgical failure with the lesion still present. In six patients (3.0%), immediate postoperative mammograms showed that the lesion had been removed, even though the lesion had not been identified on surgical-specimen radiographs. No errors occurred in the interpretation of immediate postoperative mammograms, a fact corroborated by examination of surgical specimens obtained at repeat surgery in three patients and identification of skin calcifications in two patients, and with follow-up mammograms in six patients. Whenever a discrepancy between preoperative localization radiographs and surgical-specimen radiographs exists, the authors suggest immediate postoperative mammography to improve the diagnostic process. 