Mammographic and clinicopathological features of mucinous carcinoma of the breast

Background: We attempted to improve the effectiveness of diagnostic techniques in mammographic imaging of mucinous carcinoma of the breast by defining the characteristics of mammographic images and investigating correlations between these images and various clinicopathological findings. Methods: Clinicopathological investigations of 92 lesions in 90 cases of mucinous carcinoma of the breast were made. Mammography demonstrated 80 lesions with identical tumor shadow characteristics and these were divided into three patterns, circumscribed, indistinct and blended. Correlations between clinicopathological findings and mammographic images were investigated. Results: Patients with mucinous carcinoma of the breast usually present with a palpable mass. The lymph node metastasis rate in this study was low and prognosis in the early postoperative period was satisfactory. On mammograms, the circumscribed pattern was the most frequent. The investigation of the correlation between histological subtype and mammographic pattern showed a high percentage of pure type lesions exhibited in the circumscribed pattern while those of mixed histologic type often showed the indistinct pattern. Calcification frequency demonstrated on mammography was 75% for the indistinct and mixed patterns, and approximately 50% for the circumscribed pattern. A high rate of calcification seen outside the tumor shadow suggested a high frequency of invasion and the spread of cancer to neighboring tissues. The circumscribed pattern was least frequently associated with lymph node metastasis, followed by the indistinct and blended patterns in that order. Conclusion: Investigation of clinicopathological factors and mammographic findings in mucinous carcinoma of the breast suggests that mammography provides clinically valuable information for the treatment of this disease. These findings indicate the importance of careful mommographic observation at the time of diagnosis.