[Clinicopathologic study of centrally necrotizing carcinoma of breast]

To study the clinicopathologic features and immunophenotype of centrally necrotizing carcinoma (CNC) of breast; and to study its relationship with basal-like breast cancer.

The clinical and pathologic characteristics of 35 cases of CNC were analyzed. Immunohistochemical study for estrogen receptor, progesterone receptor, HER2, CK8/18, 34betaE12, CK5/6, CK14, CK17, smooth muscle actin, p63, vimentin and epidermal growth factor receptor was performed using EnVision method. The surival information of 10 case were obtained.

The age of patients with CNC ranged from 30 to 82 years (mean = 54.2 years). Macroscopically, all tumors were relatively circumscribed, with a mean diameter of 2.4 cm. Histologically, there was a prominent central, necrotic or acellular zone surrounded by a narrow rim of viable tumor cells. The central necrotic foci had the following morphologic patterns: (1) coagulative tumor necrosis associated with various degree of fibrosis or hyaline degeneration (24 cases), (2) predominance of fibrous and scar tissue, with small amount of necrotic debris (8 cases), and (3) infarction (3 cases). The peripheral zone of tumor cells showed features of grade 3 invasive ductal carcinoma in 32 cases and grade 2 in 3 cases. Twenty cases of CNC were associated with ductal carcinoma in-situ. A component of invasive micropapillary carcinoma was identified in 5 cases. Peripheral lymphocytic infiltrates were seen in 17 cases. Immunohistochemical study of 31 cases showed that the expression rate of basal-like markers (83.9%, 26 cases) was higher than that of myoepithelial markers (38.7%, 12 cases). The percentage of basal-like subtype (64.5%, 20 cases) was higher than luminal-A (9.7%, 3 cases), luminal-B (9.7%, 3 cases), HER2 over-expression (12.9%, 4 cases) and null (3.2%, 1 case) subtypes. In 20 cases of basal-like carcinoma, the expression ratio of CK5/6 was highest amongst basal-like markers (18 cases), the other markers ratios of CK17, CK14 and epidermal growth factor receptor were 8/10, 14/19 and 8/16, respectively. Follow-up data were available in 10 patients. The follow-up duration ranged from 15 to 42 months (mean = 21.5 months). The median disease-free and overall survivals were 14.0 and 18.0 months, respectively. Disease progression (as defined by the presence of recurrence, metastasis or tumor-related death) occurred in 9 patients. The mean and median time to disease progression was 16.6 and 13.0 months, respectively.

CNC is a rare subtype of breast carcinoma and has distinctive, easily discernible morphologic features. The majority of CNC exhibits basal-like immunophenotype and carries a poor prognosis. CNC is the typical representative of basal-like breast cancer.