MFH Mimic in Breast: A High-Grade Malignant Phyllodes Tumor

Area of Science:

• Oncology
• Pathology

Background:

• Malignant phyllodes tumors (MPTs) are rare breast neoplasms characterized by a biphasic structure.
• The mesenchymal component of MPTs can exhibit diverse malignant stromal differentiations.

Purpose of the Study:

• To report a rare case of malignant phyllodes tumor with malignant fibrous histiocytoma-like stromal differentiation.
• To contribute to the understanding of the histopathological variability of malignant phyllodes tumors.

Main Methods:

• Histopathological examination of a resected tumor specimen.
• Immunohistochemical analysis to characterize the stromal component.

Main Results:

• The tumor displayed benign duct-like epithelium and a malignant mesenchymal component.
• The mesenchymal component showed features consistent with malignant fibrous histiocytoma, a rare stromal differentiation for MPTs.

Conclusions:

• Malignant phyllodes tumors can exhibit rare stromal differentiations, including malignant fibrous histiocytoma-like features.
• Accurate histopathological diagnosis is crucial for appropriate management of these rare tumors.