目的：观察乳腺原发性印戒细胞癌的形态特征。方法：通过HE及AB/PAS染色，对4例乳腺原发性印戒细胞癌进行观察。结果：4例癌细胞内印戒细胞均超过20%。HE染色呈典型印戒样细胞，AB/PAS染色胞质内阳性。导管内型及小叶型各1例，浸润性导管型及小叶型各1例。结论：乳腺原发性印戒细胞癌是一种特殊型癌，诊断时应排除转移性印戒细胞癌。“,”To understand the morphologic features of primary signet-ring cell carcinoma of the breast. Methods Four cases of primary signet-ring cell carcinoma of the breast were studied by means of HE and AB/PAS stains. Results In four cases,signet-ring cells accounted for more then 20% of the neoplastic cells. These cells were appeared as classical signet-ring form in HE staining and showed intracytoplasmic mucin by AB/PAS staining. On the basis of histological pattern, these cases were divided into four types: intraductal, lobular, infiltrating ductal, and infiltrating lobular. Conclusion Primary signet-ring cell carcinoma of the breast is a specific variant of breast carcinoma.