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Oncology23 papers

Malignant phyllodes tumor

Last edited: 4/15/2026

Overview

Malignant phyllodes tumors (PTs) are rare fibroepithelial neoplasms arising primarily in the breast, characterized by aggressive behavior and potential for local recurrence and distant metastasis 13.

Diagnosis

  • Histologic Features: Presence of stromal atypia and mitotic activity crucial for grading 1.
  • Mitotic Counting: Whole slide imaging or 10 high-power fields (HPFs) for accurate mitotic count; correlates with tumor grade and prognosis 1.
  • Dimorphic Features: Identification of benign epithelial elements supports diagnosis, especially in bilateral cases 2.
  • Imaging: Mammography and MRI useful for tumor extent and staging 3.
  • Management

  • Surgical: Wide local excision with clear margins is essential 3.
  • Adjuvant Therapy: Not routinely recommended for localized disease; consider in high-risk cases based on grade and extent 3.
  • Radiation Therapy: May be considered post-surgery for high-grade tumors to reduce recurrence risk 3.
  • Systemic Therapy: Chemotherapy reserved for metastatic disease; specific drug classes not detailed in abstracts 3.
  • Special Populations

  • Bilateral Cases: Histological confirmation required to rule out metastasis; management involves individualized surgical approaches 2.
  • Key Recommendations

  • Utilize whole slide imaging or 10 HPFs for accurate mitotic counting to guide grading and prognosis (Evidence: Moderate 1).
  • Wide local excision with clear margins is the cornerstone of surgical management for malignant phyllodes tumors (Evidence: Expert opinion 3).
  • Consider adjuvant radiation therapy for high-grade tumors to mitigate recurrence risk (Evidence: Moderate 3).
  • Histological confirmation is essential in bilateral cases to differentiate primary tumors from metastases (Evidence: Moderate 2).
  • References

    1 Chow ZL, Thike AA, Li HH, Nasir NDM, Yeong JPS, Tan PH. Counting Mitoses With Digital Pathology in Breast Phyllodes Tumors. Archives of pathology & laboratory medicine 2020. link 2 Ball AB, Fisher C. Bilateral malignant phyllodes tumours. Journal of surgical oncology 1991. link 3 Deodhar SD, Joshi S, Khubchandani S. Cystosarcoma phyllodes. Journal of postgraduate medicine 1989. link

    Original source

    1. [1]
      Counting Mitoses With Digital Pathology in Breast Phyllodes Tumors.Chow ZL, Thike AA, Li HH, Nasir NDM, Yeong JPS, Tan PH Archives of pathology & laboratory medicine (2020)
    2. [2]
      Bilateral malignant phyllodes tumours.Ball AB, Fisher C Journal of surgical oncology (1991)
    3. [3]
      Cystosarcoma phyllodes.Deodhar SD, Joshi S, Khubchandani S Journal of postgraduate medicine (1989)

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