Breast, Fibroadenoma

Fibroadenomas are the most common benign tumor of the breast. These fibroepithelial lesions usually present as a firm, well-circumscribed nodule in the breast with a rubbery, gray-white surface. They can be multiple and bilateral in nature are more common in younger women; but can also occur in all ages. These lesions are now more commonly diagnosed by core biopsy, however they have characteristic features seen from fine needle aspiration including a hypercellular aspirate with a monolayer of epithelial cells mixed with myoepithelial cells in a "staghorn" or antler-like configuration. Cellular cohesiveness is often appreciated. A fibromyxoid stroma is common, in addition to numerous bare nuclei.