ObjectiveTo summarize the clinicopathological characteristics of 94 patients with pure mucinous breast carcinoma (PMBC), and to retrospectively analyze the prognosis and the prognostic factors. MethodsNinety four patients who were pathologically diagnosed with PMBC from November 1996 to October 2011 were retrieved from the database of breast cancer in West China Hospital. The clinicopathological and long term follow-up data of these patients were analyzed retrospectively. Results① Clinicopathological characteristics:These patients accounted for 1.48% (94/6 330) of all breast cancer patients who treated in our hospital during the same period. They were all female,with a median age of 45 years old (29-85 years)and median duration of 90 d (5-2920 d). A proportion of 63.83% (60/94) of these patients were premenopausal women. Ninety three patients had unilateral lesion, one patient had bilateral lesions, totally 95 lesions. A proportion of 85.29% (58/68) tumors were in T1-T2 staging, and 82.80% (77/93) tumors were node-negative. A proportion of 1.05% (1/95) tumors had metastasized at diagnosis. A proportion of 92.54% (62/67) tumors were in Ⅰ-Ⅱ staging, 84.34% (70/83) tumors were estrogen receptor (ER) positive, 74.70% (62/83) were progesterone receptor (PR) positive, and 20.25% (16/79) were human epidermal growth factor receptor 2 (HER-2/neu) positive. A proportion of 6.32% (6/95) of tumors had breast-conserving surgery. ② Preoperative diagnosis:The detection rate of malignance were 60.87% (14/23), 83.33% (40/48), and 100% (18/18), respectively for patients who were examined with mammography, ultrasonography, and mammography+ultrasonography, and there was significant difference between the three groups (P=0.006). ③ Prognosis and prognostic factors:The follow-up rate was 80.85% (76/94). Two cases had bone metastasis respectively in 14 and 26 months after operation, one of whom died. Both five-year and ten-year overall survival rate (OS) were 98.50%, both five-year and ten-year disease-free survival rate (DFS) were 95.80%. There was no lymph node involvement in patients of T1 phase, and no recurrence, metastasis or death occurred during the follow-up. The univariate analysis showed that the disease course, T staging, TNM staging, and HER-2/neu status were statistically significant prognostic factors for DFS situation (P<0.050). ConclusionsCases in this group displayed indolent behavior and favorable prognosis which are similar to western populations. The disease course, T staging, TNM staging, and HER-2/neu status appear to be significant predictors of worse prognosis. The combination of mammography and ultrasonography could largely improve the diagnostic accuracy, and breast-conserving therapy may be recommended for patients with no contraindications.