A large number of epidemiological studies have evaluated the association between Human papillomavirus infection and breast carcinoma, but the results have been inconsistent.Numerous types of cytopathic effect are distinct in living cultures, but fixation and staining of the cells is essential to realize appearances of viral infection such as inclusion bodies. Identifying cytopathic effect and using it as a investigative tool needs much practice in observing stained section of numerous cell types. The present study aimed at diagnosing the histological changes in the malignant breast tissue, which caused by the HPV and comparing them with malignant breast tissue caused by other factors in order to find a way to diagnose the virus through the histopathic effect. A total of 100 samples was included in the study, 20 from benign tumor and 80 carcinomas, including different histopathological change. HPV was detected by using the conventional PCR. The breast cancer sections were examined for the expression of the effect of Human papillomavirus. In separate series the results of using formalin-fixed, paraffin -embedded sections were compared. Overall prevalence of HPV in malignant breast tissue was difference, we found that the histopathological characteristics of HPVassociated breast cancer are very different to breast cancercaused by other factors. Specifically, we showed the presence of HPV in breast cancer associates with the adenocarcinoma, The virus caused more activity in the tumor. Tumor is acinar carcinoma with increased cellularty and proliferative, While, in none infected with virus, there is no increased in cellularty or acinar, in some arease there was dilution of ducts.The observations indicate a likely causal role of HPV in causing a different histopathological change than breast cancercaused by other factors, This helps in the diagnosing of the HPV through cytopathic effect.