Case report: A case of malignant phyllodes tumor of the breast with concurrent epithelial malignancy and heterologous chondrosarcomatous differentiation.
The presence of malignant heterologous elements and malignant transformation of the epithelial component in phyllodes tumor (PT) is infrequent. The co-existence of both features within a single malignant PT is exceptionally rare and poorly documented. We report a unique case of a 57-year-old female with a malignant PT exhibiting both low-grade ductal carcinoma in situ (DCIS) and heterologous chondrosarcomatous differentiation. This case underscores the diagnostic challenges and therapeutic considerations for this complex tumor entity, highlighting the critical importance of extensive histopathological sampling.