Objective: Breast cancer is the most commonly seen cancer among the woman depending on environmental and etiological factors.

Materials and Methods: A hundred and ninety nine women who were diagnosed as breast cancer with needle biopsy to tumorial lesions under ultrasonography between 2016-2018, evaluated retrospectively. 28 Patients age, grades and histopathologic types of the tumors, presence of hormon receptors, proliferation rates and presence of oncogen expression were evaluated.

Results: A hundred and seventy one of 199 (85.9%) breast cancer cases were of non-special type. Modified Bloom Richardson Grading system was used for histopathological grading. Grade 1, 2, 3 were found to be 32.6%, 47.2%, 20.2% respectively. Immunohistochemical staining rate of estrogen and progesteron receptors were found to be 81.4% and 72.8% respectively. HER2 overexpression rate was 17.6% and proliferation index of Ki67 was 73.4% (below 14%).

Conclusion: Needle biopsy under ultrasonography is the most convenient method for early diagnosis and determining the treatment modality. To take in to account that breast cancer is a heterogenous tumor, determining the presence of hormon reseptors, proliferation rates and oncogenic properties according to histological subtype would be useful to decide for the personal treatment modality.