Background: Most common malignancy in women in western world is breast cancer. Ki-67 is a prognostic and proliferative marker distinguishing luminal type A from type B breast cancer.

Aims: The aim of the present study was to detect Ki-67 expression in breast carcinoma cases by IHC and to study Ki-67 expression with some histopathological features such as histological type of tumor, grade of tumor & involvement of lymph node (LN).

Study Design: Retroprospective

Material and Methods: The retroprospective study of 36 cases was conducted in the Department of Pathology at tertiary care hospital (U.P. West) during a period of 5 years.

Statistical Analysis used: It was done by a descriptive statistics and chi square test to look for any correlation between Ki-67 expression with histological type of tumor, grade of tumor and lymph node involvement. It was considered significant when p value was <0.05.

Result: Invasive carcinoma of no special type were the most common histological malignancy followed by invasive lobular carcinoma, carcinoma of neuroendocrine differentiation and metaplastic carcinoma. Majority of breast carcinoma cases showed T2 stage, Nottingham Modified Bloom Richardson System grade II and lymph node positivity. 63.89% cases of breast cancer were under group 1 of Ki-67 positivity, 25% were under group 2 Ki-67 positivity and 11.11% cases showed group 3 Ki-67 positivity.

Conclusion: Invasive carcinoma of no special type was the commonest histological type. No statistically significant association of Ki-67 positivity was found with grade, histological type, TNM stage & lymph node positivity.

Keywords: Breast; Ki-67; Cancer; Positivity; Grade.