Myofibroblastoma of breast.

Soft tissue neoplasms of breast thought to be derived from Myofibroblasts have been classified as myofibroblastomas. Myofibroblasts are spindle shaped mesenchymal cells derived from fibroblasts. These are rare neoplasms (more often seen in the male breast) and have same structural and immunohistochemical characteristics as those of solitary fibrous tumors. We present a case of an adult female presenting as firm breast lump diagnosed as myofibroblastoma and confirmed by diffuse positivity of CD34 immunohistochemical stain.