Fine‐needle aspiration features of ossifying fibromyxoid tumor in the breast: A case report and literature review

: Ossifying fibromyxoid tumor (OFT) is a very rare soft tissue tumor which is characterized by incomplete peripheral mature bone shell. To date, cytological features of OFT have been poorly studied with only seven case reports. In this study, an additional case of OFT investigated by fine-needle aspiration is presented. A 75-year-old man with advanced nasopharyngeal carcinoma presented with peripherally calcified right breast mass. Smears were hypercellular and stroma-rich. Tumor cells were mainly dispersed, with epithelioid morphology and eccentrically located nuclei. In the background, there was abundant eosinophilic myxoid secretion. No necrosis, atypia, or mitotic activity was found. The tumor showed diffuse S-100, CD10, STAT6 expression and focal desmin, estrogen receptor (ER), and progesteron receptor (PgR) expression. Fluorescence in situ hybridization study revealed PHF1 rearrangement in 9% of cells. Cytological characteristic of OFT is quite distinctive and precise diagnosis can be made, especially when it is coupled with compatible radiological findings.