Radiology, Vol 186, 681-684, Copyright © 1993 by Radiological Society of North America
Polyhedral microcalcifications at mammography: histologic correlation with calcium oxalate
C Frouge, M Meunier, JM Guinebretiere, R Gilles, D Vanel, G Contesso, R Di Paola and M Blery
Department of Radiology, Hopital de Bicetre, Kremlin Bicetre, France.
Pathologists have associated calcium oxalate dihydrate (weddellite) in
breast biopsy specimens with benign or borderline lesions and rarely with
malignancy. These microcalcifications may have a polyhedral shape in
histologic specimens owing to their crystalline structure. A retrospective
radiologic-histologic correlation study was performed on 300 clusters of
microcalcifications to determine if microcalcifications with a polyhedral
shape could be found at mammography. In 19 cases (6.3%), polyhedral
microcalcifications (PMs) were detected by two radiologists. In 12 of these
19 cases, weddellite crystals were found in the histologic specimen under
polarized light; in seven cases, no calcification was found. Although rare,
PMs can be found at mammography by radiologists aware of their existence.
They are due to weddellite crystals and in this series were associated with
benign disease in 89% of cases. Prospective studies are required to
determine the frequency of PMs on screening mammograms and to evaluate
their negative predictive value.
