Immunohistochemical Expression of p63 in Benign and Malignant Breast Lesions

Abstract

Introduction: Breast carcinoma demands attention as it causes high morbidity and mortality. It is important to recognise benign lesions to distinguish them from in situ and invasive breast cancer and to assess a patient’s risk of developing breast cancer, so that the most appropriate treatment modality for each case can be established. The p63 has been characterised as a reliable marker of myoepithelial cells of lactiferous duct. It is exclusively expressed in myoepithelial cells of normal breast tissue. Hence, p63 can be of great help in the differential diagnosis involving benign lesions. Also, p63 may aid in distinguishing benign from malignant lesions. Aim: To study the Immunohistochemistry (IHC) expression of p63 in benign and malignant breast lesions. Materials and Methods: The prospective study was conducted on 76 breast specimens for a period of one year, from 1st December 2018 to 30th November 2019 in the Department of Pathology, Bhagat Phool Singh, Government Medical College for Women, Khanpur Kalan, Sonepat, Haryana, India. IHC assessment for p63 nuclear protein was performed. The intensity of p63 expression was evaluated as continuous positive, discontinuous positive and negative. The extent was scored on the basis of percentage of positive cells and assigned a score of negative (0%), 1 (<25%), 2 (26-90%) and 3 (91-100%). Results: Out of 76 cases, 38 cases were diagnosed as benign and 38 cases as malignant. IHC staining with p63 showed nuclear positivity in all benign lesions. Among malignant lesions, four were positive and 34 were negative. Conclusion: According to the above results, p63 is a very useful IHC marker in diagnosing difficult cases, cases of carcinoma in situ, borderline cases and cases with inconclusive histomorphological diagnosis.

Keywords

• ductal carcinoma in situ
• fibroadenoma
• invasive ductal carcinoma
• myoepithelial cells