Clinicopathological characteristics of atypical cystic duct (ACD) of the breast: Assessment of ACD as a precancerous lesion

• Published in: Pathology international Vol. 50; no. 10; pp. 793 - 800
• Main Authors: Kusama, Ritsu, Fujimori, Minoru, Matsuyama, Ikuo, Fu, Li, Ishii, Keiko, Hama, Yoshihisa, Asanuma, Kazuhiko, Shingu, Kiyoshi, Kobayashi, Shinya, Tsuchiya, Shin-ichi
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Blackwell Science Pty 01.10.2000
• Subjects: Adult; Aged; atypical cystic duct; Biomarkers, Tumor - analysis; breast neoplasm; Breast Neoplasms - chemistry; Breast Neoplasms - pathology; Breast Neoplasms - surgery; Carcinoma in Situ - chemistry; Carcinoma in Situ - pathology; Carcinoma in Situ - surgery; Carcinoma, Ductal, Breast - chemistry; Carcinoma, Ductal, Breast - pathology; Carcinoma, Ductal, Breast - surgery; Female; Humans; Immunoenzyme Techniques; Lymph Nodes - pathology; Lymphatic Metastasis - pathology; Middle Aged; Neoplasm Proteins - analysis; Precancerous Conditions - chemistry; Precancerous Conditions - pathology; Precancerous Conditions - surgery; precancerous lesion; Premenopause; Receptors, Estrogen - analysis; Receptors, Progesterone - analysis
• ISSN: 1320-5463; 1440-1827
• DOI: 10.1046/j.1440-1827.2000.01121.x

To clarify the clinicopathological features of an atypical cystic duct (ACD) as defined by Tsuchiya’s criteria as a precancerous lesion of the breast, we used 200 whole mammary gland serial sections of breast cancer. Forty‐four (22%) of the 200 breast cancer patients had ACD breast lesions. The frequency of patients with ACD increased in premenopausal women (P= 0.001). There was no correlation between the ACD‐present group and the ACD‐absent group for immunohistochemical status of the estrogen receptor (ER), progesterone receptor (PgR), p53, or c‐erbB2; Ki‐67 labeling index of cancer tissues; size of tumor, or lymph node metastases. A number of ACD lesions displayed continuity to cancer lesions. In 500 serial sections of a paraffin‐embedded tissue of a ACD case at 3 μm intervals, an apparent transition from ACD into ductal carcinoma in situ was observed. Immunohistochemical analysis using α‐smooth muscle actin showed that myoepithelial cells of ACD stained strongly, and their nuclei and cytoplasm were thinning. In 16 of the 44 (36%) ACD‐present patients, carcinoma cells stained positive for p53. Within those 16 cases, 12 cases (75%) were positive for p53 in ACD lesions. There was a significant correlation between the expression of p53 protein in malignant cells and ACD (P= 0.001). All 44 ACD lesions had no staining of c‐erbB2, regardless of staining in malignant lesions. The mean Ki‐67 labeling index of ACD lesions was low (0.3%), suggesting that ACD had a low proliferative rate. We suggest that ACD is the precancerous breast lesion because of a histologic continuum between ACD and malignancy, and because of p53 protein expression in ACD.