{"entity":{"id":"phyllodes-tumour","kind":"cancer","name":"Phyllodes tumour of the breast","aka":["Cystosarcoma phyllodes (historical)","Fibroepithelial tumour of the breast","Malignant phyllodes tumour"],"tldr":"A phyllodes tumour is a fast-growing, usually painless breast lump of gland and connective tissue that forms leaf-like fronds. Most are benign, some borderline and a few malignant, behaving like a sarcoma and spreading through the blood. Treatment is surgery with a rim of normal tissue; radiotherapy is considered for higher grades, and chemotherapy has little proven role.","summary":"Phyllodes tumours are fibroepithelial tumours in which the stroma, not the epithelium, is the neoplastic component; the epithelium is stretched into the leaf-like clefts that give the name. The World Health Organization grades them benign, borderline or malignant on stromal cellularity, nuclear atypia, mitotic count, stromal overgrowth and the character of the border, and most are benign. They present as a smooth, mobile, often large lump that has grown quickly over months, in women a decade older than those with fibroadenoma. Imaging cannot reliably separate the two, and a core biopsy often returns only a fibroepithelial lesion, so any rapidly growing or large fibroepithelial lesion is excised for diagnosis. Benign phyllodes tumours and fibroadenomas share MED12 mutations, and TERT promoter mutations accumulate in borderline and malignant tumours.\n\nSurgery is the treatment for every grade. Wide local excision with clear margins is the aim, and mastectomy is reserved for tumours too large for the breast; the traditional demand for a 1 cm margin has softened, and guidelines now accept any negative margin for benign tumours while recommending re-excision for positive margins in borderline and malignant disease. Lymph node metastases are rare, so sentinel node biopsy and axillary dissection are not performed. Adjuvant radiotherapy has no randomised evidence: a single-arm phase 2 study of 46 borderline and malignant tumours treated with margin-negative breast-conserving surgery and radiotherapy reported no local recurrences, and guidelines list radiotherapy as a consideration after breast conservation for these grades. Adjuvant chemotherapy has no proven benefit and hormone receptors, though often present in the epithelium, do not guide treatment.\n\nBenign tumours are cured by excision and recur locally in a minority, often at a higher grade than the original. Malignant tumours recur locally more often and a substantial minority metastasise, most often to the lungs and bone within the first few years, at which point they are treated like soft-tissue sarcomas with doxorubicin-based chemotherapy and have a poor outlook. Follow-up with examination and imaging for the first few years catches most recurrences. The rarity of the disease means margin width, the role of radiotherapy and the value of molecular grading rest on retrospective series and registries rather than trials.","asOf":"2026-09-17","wikipedia":"https://en.wikipedia.org/wiki/Phyllodes_tumor","links":[{"label":"NCCN Guidelines: Breast Cancer (phyllodes tumour section)","url":"https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1419"},{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Phyllodes_tumor"}],"tags":["subtype-page"],"related":["sarcoma"],"cancers":[],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":["b-rare-cancers"],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"group":"breast","burden":"Under one percent of breast tumours, typically in women in their forties, a decade later than fibroadenoma; most are benign, and only the malignant minority behave as sarcomas and spread.","subtypes":["Benign phyllodes tumour (most; excision alone)","Borderline phyllodes tumour (wide excision, radiotherapy considered)","Malignant phyllodes tumour (sarcoma-like; wide excision or mastectomy, radiotherapy, sarcoma chemotherapy if metastatic)","Phyllodes tumour with heterologous sarcomatous elements (liposarcoma, osteosarcoma)","Recurrent phyllodes tumour (often a higher grade than the original)"],"biomarkers":["WHO grade from stromal cellularity, atypia, mitotic count, stromal overgrowth and border (benign, borderline, malignant)","Margin status after excision","Tumour size relative to the breast","MED12 mutation (shared with fibroadenoma) and TERT promoter mutation (borderline and malignant)","No routine hormone receptor or HER2 testing (stroma-driven tumour)","Chest CT for metastases in malignant tumours"],"standardOfCare":[{"setting":"Diagnosis","approach":"Ultrasound and mammography, core needle biopsy, and excision of any rapidly growing or large fibroepithelial lesion because biopsy cannot reliably separate phyllodes tumour from fibroadenoma.","refs":["ultrasound","mammography","core-needle-biopsy","histopathology-ihc"]},{"setting":"Benign phyllodes tumour","approach":"Complete excision with clear margins; observation if margins are close after a benign diagnosis.","refs":["lumpectomy"]},{"setting":"Borderline and malignant phyllodes tumour","approach":"Wide excision aiming for clear margins or mastectomy for large tumours, no axillary staging, and adjuvant radiotherapy considered after breast conservation.","refs":["lumpectomy","mastectomy","imrt-igrt"]},{"setting":"Metastatic malignant phyllodes tumour","approach":"Treated as a soft-tissue sarcoma with doxorubicin-based chemotherapy; no proven benefit from adjuvant chemotherapy.","refs":["doxorubicin","sarcoma"]}],"stateOfArt":["Margin requirements have relaxed for benign tumours, sparing breast tissue.","Molecular grading with TERT promoter and other mutations is being tested against histology.","Radiotherapy after breast conservation is accepted as an option for borderline and malignant tumours on single-arm evidence."],"history":[{"year":1838,"title":"Johannes Müller names cystosarcoma phyllodes","refs":[]},{"year":1981,"title":"World Health Organization adopts phyllodes tumour with benign, borderline and malignant grades","refs":[]},{"year":2009,"title":"Single-arm phase 2: no local recurrences after breast conservation with radiotherapy for borderline and malignant tumours","refs":["imrt-igrt"]},{"year":2015,"title":"MED12 and TERT promoter mutations mapped across fibroepithelial tumours","refs":[]}],"pipeline":["imrt-igrt"],"openProblems":["No randomised trial has tested margin width or radiotherapy.","Core biopsy cannot reliably distinguish phyllodes tumour from fibroadenoma.","Metastatic malignant phyllodes tumour has no effective systemic therapy.","Grading is subjective at the benign-borderline and borderline-malignant boundaries."],"parent":"breast-cancer"},"route":"/cancers/phyllodes-tumour/","neighbours":{"cancer":[{"id":"breast-cancer","kind":"cancer","name":"Breast cancer (all types)","route":"/cancers/breast-cancer/"},{"id":"sarcoma","kind":"cancer","name":"Sarcomas (soft tissue, bone, GIST)","route":"/cancers/sarcoma/"}],"bottleneck":[{"id":"b-rare-cancers","kind":"bottleneck","name":"Rare and paediatric cancers without markets","route":"/bottlenecks/b-rare-cancers/"}],"technology":[{"id":"histopathology-ihc","kind":"technology","name":"Histopathology & immunohistochemistry","route":"/technologies/histopathology-ihc/"},{"id":"imrt-igrt","kind":"technology","name":"IMRT / IGRT (modern external beam)","route":"/technologies/imrt-igrt/"},{"id":"mammography","kind":"technology","name":"Mammography & tomosynthesis","route":"/technologies/mammography/"},{"id":"ultrasound","kind":"technology","name":"Ultrasound","route":"/technologies/ultrasound/"}],"term":[{"id":"core-needle-biopsy","kind":"term","name":"Core needle biopsy and fine-needle aspiration (FNA)","route":"/terms/core-needle-biopsy/"},{"id":"lumpectomy","kind":"term","name":"Lumpectomy (breast-conserving surgery)","route":"/terms/lumpectomy/"},{"id":"mastectomy","kind":"term","name":"Mastectomy","route":"/terms/mastectomy/"}],"drug":[{"id":"doxorubicin","kind":"drug","name":"Doxorubicin","route":"/drugs/doxorubicin/"}]}}