PDFs by language
Our 24/7 cancer helpline provides support for people dealing with cancer. We can connect you with trained cancer information specialists who will answer questions about a cancer diagnosis and provide guidance and a compassionate ear.
Chat live online
Select the Live Chat button at the bottom of the page
At our National Cancer Information Center trained Cancer Information Specialists can answer questions 24 hours a day, every day of the year to empower you with accurate, up-to-date information to help you make educated health decisions. We connect patients, caregivers, and family members with valuable services and resources.
Or ask us how you can get involved and support the fight against cancer. Some of the topics we can assist with include:
For medical questions, we encourage you to review our information with your doctor.
Phyllodes tumors (or phylloides tumors) are rare breast tumors that start in the connective (stromal) tissue of the breast, not the ducts or glands (which is where most breast cancers start). Most phyllodes tumors are benign and only a small number are malignant (cancer).
Phyllodes tumors are most common in women in their 40s, but women of any age can have them. Women with Li-Fraumeni syndrome (a rare, inherited genetic condition) have an increased risk for phyllodes tumors.
Phyllodes tumors are often divided into 3 groups, based on how they look under a microscope:
Phyllodes tumors are usually felt as a firm, painless breast lump, but some may hurt. They tend to grow large fairly quickly, and they often stretch the skin.
Sometimes these tumors are seen first on an imaging test (like an ultrasound or mammogram), in which case they’re often hard to tell apart from fibroadenomas.
The diagnosis can often be made with a core needle biopsy, but sometimes the entire tumor needs to be removed (during an excisional biopsy) to know for sure that it’s a phyllodes tumor, and whether it's malignant or not.
Having a benign phyllodes tumor does not affect your breast cancer risk. If you have a malignant phyllodes tumor, it does not affect your risk of getting other types of breast cancer. Still, you may be watched more closely and get regular imaging tests after treatment for a phyllodes tumor, because these tumors can sometimes come back after surgery.
Phyllodes tumors typically need to be removed completely with surgery.
If the tumor is found to be benign, an excisional biopsy might be all that is needed, as long as the tumor was removed completely.
If the tumor is borderline or malignant, a wider margin (area of normal tissue around the tumor) usually needs to be removed as well. This might be done with breast-conserving surgery (lumpectomy or partial mastectomy), in which part of the breast is removed. Or the entire breast might be removed with a mastectomy, especially if a margin of normal breast tissue can't be taken out with breast-conserving surgery. Radiation therapy might be given to the area after surgery, especially if it’s not clear that all of the tumor was removed.
Malignant phyllodes tumors are different from the more common types of breast cancer. They are less likely to respond to some of the treatments commonly used for breast cancer, such as the hormone therapy or chemotherapy drugs normally used for breast cancer. Phyllodes tumors that have spread to other parts of the body are often treated more like sarcomas (soft-tissue cancers) than breast cancers.
Phyllodes tumors can sometimes come back in the same place. Because of this, close follow-up with frequent breast exams and imaging tests are usually recommended after treatment.
The American Cancer Society medical and editorial content team
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.
Calhoun KE, Allison KH, Kim JN, Rahbar H, Anderson BO. Chapter 62: Phyllodes tumors. In: Harris JR, Lippman ME, Morrow M, Osborne CK, eds. Diseases of the Breast. 5th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2014.
Grau AM, Chakravarthy AB, Chugh R. Phyllodes tumors of the breast. UpToDate. 2021. Accessed at https://www.uptodate.com/contents/phyllodes-tumors-of-the-breast on November 1, 2021.
Guray M, Sahin AA. Benign breast diseases: Classification, diagnosis, and management. Oncologist. 2006;11;435-449.
Hartmann LC, Sellers TA, Frost MH, et al. Benign breast disease and the risk of breast cancer. N Engl J Med. 2005;353:229-237.
Henry NL, Shah PD, Haider I, et al. Chapter 88: Cancer of the breast. In: Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 6th ed. Philadelphia, Pa: Elsevier; 2020.
Jagsi R, King TA, Lehman C, et al. Chapter 79: Malignant tumors of the breast. In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 11th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2019.
Moutte A, Chopin N, Faure C, et al. Surgical management of benign and borderline phyllodes tumors of the breast. Breast J. 2016;22(5):547-552.
National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology. Breast Cancer. Version 8.2021. Accessed at www.nccn.org/professionals/physician_gls/pdf/breast.pdf on November 2, 2021.
Orr B, Kelley JL. Benign breast diseases: Evaluation and management. Clin Obstet Gynecol. 2016;59(4):710-726.
Last Revised: June 15, 2022
American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.