Myofibroblastoma of the breast: Presentation of three cases E. Kairi-Vasilatou * , C. Dastamani, A. Tsagkas, A. Paraskeva, A. Kondi-Pafiti * Aretaieio Nosokomeio University, Dept. of Histopathology, Athens, Greece Objective: Myofibroblastoma is a rare, usually solitary, benign spindle cell tumour composed of myofibroblasts. It affects both genders equally. Method: Three cases diagnosed in our laboratory are presented. Results: Two patients were postmenopausal females (53 and 75 years old) and one was male (55 years old). The tumour was 1,6 cm in greatest diameter in the first case, 7 cm in the second and 2 cm in the third. Microscopically, all neoplasms were circumscribed and consisted of uniform, bland spindle cells separated by broad bands of hyalinized collagen. The neoplasmatic cells had abundant eosinophilic cytoplasm, oval nuclei and were arranged in fascicles. Cellular atypia was found only in one case and mitoses were scarce. Immunohistochemically, all neoplasms were strongly positive for vimentin, CD34 and Bcl-2, while the expression of desmin and SMA varied. S-100 protein was negative. The neoplasms of the female patients were strongly positive for ER and negative for PgR. The stains for estrogen and androgen receptors were not carried out in the case of the male patient. Conclusion: Differential diagnosis can be complex. Fibromatosis of the breast, nodular fasciitis, myoepithelioma, myofibrosarcoma, solitary fibrous tumor, inflammatory myofibroblastic tumour should be excluded based on the histological and immunohistochemical findings. Method: Using light-and transmission electron microscopy fragments of mammary gland tumors, received intraoperative, from 58 patients 26-82 years with infiltrative ductal breast cancer were studied. Results: Most of the mast cells were localized in the areas of infiltrative growth, at a background of lymphohistiocyte infiltration and in peripheral part of the tumor. Intratumourous mast cells were totally degranulated. The mast cells with intact structure at a background of cells and tissue destruction were also in mammary gland. In destructive mast cells the nucleus with electron-dense circle and chain of granules were observed. On transmission electron microscopy their deformations and the decrease of density were revealed. The mast cells were of elongated of rounded shape with large nucleus and invaginations of karyolemma. The nucleus occupies almost completely the cell's area. It has a ring of large but pale granules. Small protuberances were observed on the surface of the cell membrane. Their number decreased in direct proportion to the size of must cells and their remoteness from microvessels. Such protuberances are necessary for mast cells in moving. Destructively changed cells with the signs of swelling, vacuolization and clasmatosis were frequent in breast cancer. Objective: Determination of eligibility of breast cancer patients for treatment with anti-angiogenic drugs has been always considered as a challenge for oncologists. Each mutation in the genes of proliferation phase enhances the angiogenesis of tumor. We aimed to determine the effect of concurrent mutations of HER-2 and TP53 on angiogenesis. Method: 32 Women affected by invasive ductal carcinoma (IDC) sporadic breast cancer were included. Immunohistochemical study was performed with HER-2, TP53, Ki-67 and AnnexinV markers. Angiogenesis index was semiquantitatively calculated by MVD-CD34 technique. Statistical associations between parameters were evaluated. Results: Prevalence of HER-2 positive and TP53 positive cases were 21.4 % and 20.0 %, respectively. 6.5 % of patients showed concurrent mutation of these genes. Concurrent mutation led to significant increases in both angiogenesis and proliferation and a significant decrease in apoptosis. There was no statistically significant association between concurrent mutation and tumor grade. Conclusion: This study demonstrates that most of the tissue prognostic factors are poor in concurrent mutation of both genes. Also, our study illustrates that the concurrent mutation correlates with a higher angiogenesis and thus an increased risk of recurrence. We can conclude that in priority setting for administration of anti-angiogenic agents, patients with concurrent mutations are more eligible.