Phyllodes tumor
Phyllodes tumor, also known as cystosarcoma phyllodes, is a rare fibroepithelial tumor of the breast which has some resemblance to a fibroadenoma. It is typically a large, fast growing mass that forms from the periductal stroma of the breast.
Epidemiology
Phyllodes tumors account for less than 0.3-1% of all breast neoplasms. It is predominantly a tumor of adult women, with very few examples reported in adolescents. The occurrence is most common between the ages of 40 and 60, before the menopause (peak incidence ~45 years). This is about 15 years older than the typical age of patients with fibroadenoma.
Clinical presentation
Patients typically present with a painless, rapid growing breast mass for which imaging is requested.
Pathology
Its original term cystosarcoma phyllodes was coined in view of its leaflike pattern of growth. A phyllodes tumor may be considered benign, borderline, or malignant depending on histologic features including stromal cellularity, infiltration at the tumor edge, and mitotic activity. At histologic analysis, the tumor can resemble a giant fibroadenoma with both epithelial and stromal components being seen.
Fine needle aspiration is inaccurate, and even core biopsy has moderate sensitivity due to tumor heterogeneity causing inadequate sampling.
Radiographic features
The tumors can be quite large at presentation.
Mammography
Typically seen as non-specific large rounded oval or lobulated, generally well circumscribed, lesions with smooth margins. A radiolucent halo may be present. Calcification (typically coarse and plaque like) may be seen in a very small proportion.
Ultrasound
General sonographic features are non-specific and can mimic that of a fibroadenoma .
On ultrasound, an inhomogeneous, solid-appearing mass is the most common manifestation. A solid mass containing single or multiple, round or cleft like cystic spaces and demonstrating posterior acoustic enhancement strongly suggests the diagnosis of phyllodes tumor. Vascularization is usually present in the solid components.
In practice, most lesions are indistinguishable from fibroadenomas on both mammography and ultrasound. This is why interval enlargement of a "fibroadenoma" is seen as an indication for a needle biopsy. Large lesions (i.e. >4 cm) may qualify for excision out of hand because needle biopsy may not be representative of the pathology in the whole lesion.
MRI
As with mammography, they are typically seen as oval, round, or lobulated masses with circumscribed margins. Signal characteristics can vary with histological grade but in general, are:
- T1: usually of low signal
- T2: can be variable ranging from homogenous low to high signal
- T1 C+ (Gd): the solid components enhance after contrast administration
- dynamic contrast: the kinetic curve pattern can be gradual slow or have rapid enhancement
An inhomogeneous signal may rarely result in the context of accompanying hemorrhage or cystic spaces . Some suggest the inhomogeneous signal as indicative of benignity .
Treatment and prognosis
It is a locally invasive tumor. Treatment is usually with surgical excision. Large tumors may even require a full mastectomy. Both benign and malignant phyllodes tumors have a tendency to recur if not widely excised. Malignant degeneration is seen in 5-25% (malignant phyllodes tumor).
After wide local excision, there is relatively frequent local recurrence (up to 25%) and up to 10% can metastasize. The mode of metastases in such cases is by haematogenous route.
History and etymology
The name is derived from the Greek word: "phullon" meaning "leaf". Phyllodes tumors were first described in 1838 by Johannes Muller as "cystosarcoma phyllodes".
Differential diagnosis
For ultrasound and MRI appearances consider :
- fibroadenoma of the breast
- calcification is more common
- primary sarcoma of the breast
Siehe auch:
- Fibroadenom
- medullary breast carcinoma
- chronic galactocele
- invasives muzinöses Mammakarzinom
- Neoplasien der Mamma
- maligner Phylloidestumor
und weiter:
Assoziationen und Differentialdiagnosen zu Phylloidestumor:
