Malignant phyllodes tumor with heterologous sarcomatous element: A rare case report

Phyllodes tumors being a rare neoplasm of the breast attributes only 0.3% to 1% of all breast tumors, with an annual incidence of about 2 per million women. Malignant differentiation of phyllodes tumors can occur, resulting in cases of extremely rare heterologous sarcomatous differentiation. We present a rare case of a 63-year-old women with features of malignant phyllodes with sarcomatous (chondrosarcomatous) differentiation. Morphologically, phyllodes tumors are categorized as benign, borderline and malignant based on the scope of stromal atypia, mitotic activity, stromal overgrowth, and the tumor margins. The presence of heterologous elements in a phyllodes directly upgrades it to a malignant category. A close follow-up with a CT scan is of utmost need to detect the recurrence and metastasis to the earliest.