PURPOSE: To determine the frequency of stability in malignant microcal
cifications and its relationship to specific histologic diagnoses. MAT
ERIALS AND METHODS: During a 34-month period, microcalcifications were
proved malignant in 182 patients referred for needle-guided biopsy. I
n 105 patients, the mammograms were compared with one or more than one
previous mammogram. These patients were classified on the basis of in
terval change in two groups: those with stable and those with increasi
ng or new microcalcifications. The histologic diagnoses were reviewed.
RESULTS: Microcalcifications were stable for 8-63 months (mean, 25.4
months) in 26 patients (24.8%), only three (12%) of whom had invasive
ductal carcinoma, Which was found in 29 (37%) of the 79 patients with
increasing or new microcalcifications. CONCLUSION: The odds for presen
ce of invasive ductal carcinoma are statistically significantly lower
(P < .025) among patients with stable microcalcifications than among t
hose with increasing or new microcalcifications. Stability of indeterm
inate or suspicious microcalcifications is unreliable for exclusion of
a diagnosis of malignancy.