Mammary myofibroblastoma: Report of two cases with fine‐needle aspiration cytology and review of the cytology literature

Fine-needle aspirates from two histologically, immunohistochemically, and ultrastructurally confirmed mammary myofibroblastomas (MM) of two elderly women revealed abundant, randomly arranged single and clustered benign spindle-shaped mesenchymal cells with scant cytoplasm and elongated or oval nuclei displaying a finely granular chromatin pattern and inconspicuous nucleoli. In one case a few cells showed inconspicuous nuclear grooves. The aspirated tumor cells from the other case stained positively with desmin and CD34 antibodies and negatively with cytokeratin and S-100 protein antibodies, in keeping with an MM. A review of the literature was briefly presented.