Phyllodes tumor | |
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Micrograph of a phyllodes tumor (right of image) with the characteristic long clefts and myxoid cellular stroma. Normal breast and fibrocystic change are also seen (left of image). H&E stain. | |
Classification and external resources | |
ICD-10 | C50, D24, D48.6 |
ICD-9-CM | 217 |
ICD-O | M9020 |
DiseasesDB | 3396 |
eMedicine | med/500 |
MeSH | D003557 |
Phyllodes tumors (from Greek: phullon leaf), also cystosarcoma phyllodes, cystosarcoma phylloides and phylloides tumor, are typically large, fast-growing masses that form from the periductal stromal cells of the breast. They account for less than 1% of all breast neoplasms.
Phyllodes tumors are a fibroepithelial tumor composed of an epithelial and a cellular stromal component. They may be considered benign, borderline, or malignant depending on histologic features including stromal cellularity, infiltration at the tumor's edge, and mitotic activity. All forms of phyllodes tumors are regarded as having malignant potential. A large series from the M.D. Anderson Cancer Centre reported the incidence of each as benign (58%), borderline (12%), and malignant (30%). Malignant phyllodes tumours behave like sarcomas and can develop blood-borne metastases. Approximately 10% of patients with phyllodes tumours develop distant metastases and this can go up to 20% in patients with histologically malignant tumours. The commonest sites for distant metastases are the lung, bone, and abdominal viscera. Rare sites of metastasis like to parotid region have also been described.
They are classified as a fibroepithelial tumor by ICD-O, but not by MeSH.
Women as young as 14 years old have developed the malignant form and it seems to be more aggressive in younger women.
This is predominantly a tumor of adult women, with very few examples reported in adolescents. Patients typically present with a firm, palpable mass. These tumors are very fast-growing, and can increase in size in just a few weeks. Occurrence is most common between the ages of 40 and 50, prior to menopause. This is about 15 years older than the typical age of patients with fibroadenoma, a condition with which phyllodes tumors may be confused. They have been documented to occur at any age above 12 years (reference needed).