Background: The association between subtypes of mammographic findings and histopathological tumor extension in patients with ductal carcinoma in situ has remained unclear. The purpose of this study was to investigate the relationship between tumor extension on mammography, by stratifying four subtypes, and histopathological tumor size in patients with ductal carcinoma in situ.
Methods: This study was performed on 109 breasts with ductal carcinoma in situ. They were treated by mastectomy at our Hospital between January 1990 and December 1999. Findings on mammography were categorized as microcalcification type, spiculated type, circumscribed type or fibrocystic-change type. The microcalcification type consisted of breasts with malignant microcalcifications, regardless of the presence or absence of tumor shadow. We analyzed the relationship between tumor size on mammography in each category and histopathological tumor size. In the breasts with palpable tumors, we compared palpated tumor size and histopathological tumor size according to the mammographic subtypes.
Results: There was no statistical difference between mammographic tumor size and histopathological tumor size for each mammographic subtype (microcalcification type, P = 0.60; spiculated type, P = 0.72; circumscribed type, P = 0.055). The size of the ductal carcinoma in situ in microcalcification and spiculated type was estimated approximately by mammography. However, mammography tended to overestimate the circumscribed type. In the cases of palpable tumor, we statistically underestimated the size of ductal carcinoma in situ by palpation in microcalcification and fibrocystic-change type (microcalcification type, P = 0.0001; fibrocystic-change type, P = 0.040).
Conclusion: Mammographic categorization is useful for surgical planning of ductal carcinoma in situ, particularly when considering breast-conserving surgery.