Abstract

Objectives: To study stromal CD34 expression in benign and malignant breast lesions and evaluate whether loss of CD34 is specific for invasive disease.

Material and methods: 317 cases of benign and malignant breast lesions were studied over a period of 2 years (July 2012 to June 2014). All the cases underwent routine processing followed by H and E staining. 178 cases underwent CD34 immunohistochemical staining and semi quantitative assessment. Further, 74 cases of infiltrating ductal carcinoma were evaluated to determine relation of stromal CD34 expression with histological grade and lymph node metastasis.

Results: Normal breast showed retained CD34 expression in 90.9% cases. Among benign lesions, 83% cases showed retained stromal CD34 expression (except cases of apocrine metaplasia, intraductal papilloma and fibroadenoma with focal atypia which showed reduced expression in 46.67%, 100% and 33.3% cases respectively). Both DCIS and LCIS showed reduced expression. Malignant tumors showed grade 0 staining in 97.9% cases, irrespective of the histological type. Statistically significant differences in stromal CD34 expression were observed between:

Malignant phyllode`s tumor compared to its benign counterpart

Papilloma and papillary carcinoma

Benign and malignant lesions overall

No significant correlation was found between CD34 expression and histological grade or lymph node metastasis. The metastatic foci in node positive patients showed a similar pattern of CD34 expression in the lymph nodes as those seen in the breast.

Conclusion: Owing to the significant differences in CD34 expression between benign and malignant breast lesions, it can potentially be used to differentiate between the two and can serve as an important diagnostic marker. Further studies can also be undertaken to establish its role as a therapeutic target in cases of breast cancer.

Keywords: Breast; Cancer; Stroma; Myofibroblasts; CD34