HOME PAGE PRACTICE & PROTOCOLS INVESTIGATIONS BENIGN / BORDERLINE MALIGNANT CASE MATERIAL

Phyllodes Tumours





Clinical basics





Classification and behaviour of Phyllodes Tumours (PTs)



Classification




Behaviour




  Benign Borderline Malignant
Local Recurrence (%) 15 25 30
Distant Metastases (%) 0 5 20


Note:




Pathological problems



Excisions:



Cores:



Excisions and cores:



Pre-operative diagnosis of PTs


Main points to be considered:




The following three illustrations from a core biopsy of a FIBROADENOMA sets the scene for discussion about assessing core biopsies in suspected PTs



Core biopsy of a fibroadenoma showing even distribution of epithelial and stromal components and low/moderate stromal cellularity
Low power view of a fibroadenoma core biopsy Medium power view of a core biopsy of a fibroadenoma


The green line shows the demarcation between specialised stroma (red arrows) around glands (note orientation of stromal fibroblasts) and the non-specialised stroma (A)
Low power view of a fibroadenoma core biopsy



The following sequence of four images are from a core from a 5cm mass in a young woman (< 30 yrs) with a history of a previous lesion at the site.

The biopsies were reported as supicious of phyllodes tumour for discussion at a multidisciplinary meeting (MDM) to guide further management.

At the MDM it was decided to excise the lump with a narrow margin of normal breast tissue - the alternatives were to "shell out" or carry out a formal wide excision.


The red arrows indicate areas of hypercellular stroma while the blue arrow shows less cellular stroma. Note also the relatively poor representation of specialised stroma in these biopsies
Low power view of a core biopsy from a suspected phyllodes tumour



The left hand image shows a focus of increased stromal cellularity (top left of picture).
The right hand image shows a solitary stromal mitosis (black arrow) within specialised stroma adjacent to glandular epithelium (red arrow).
Medium power view of a core biopsy from a suspected phyllodes tumour High power view of a core biopsy of a suspected phyllodes tumour showing a stromal mitosis


Low power view of another area of this biopsy showing variable stromal cellularity: (A) hypercellular; (B) normocellular. The distinction between specialised and non-specialised stroma is partly lost.
Low power view of a core biopsy from a suspected phyllodes tumour



Core biopsy of a subsequently confirmed PT:



The central area of this core shows the leaf like 'intra-canalicular' pattern typical of PTs. Note also the variability of stromal cellularity in different areas of this biopsy and in particular the hypercellularity of the stroma in the central section.
Low power view of a core biopsy from a suspected phyllodes tumour



The left hand image shows a focus of increased stromal cellularity.
The right hand image shows three stromal mitoses (arrows) within specialised stroma adjacent to glandular epithelium - also see insert.
Medium power view of a core biopsy from a suspected phyllodes tumour High power view of a core biopsy of a suspected phyllodes tumour showing a stromal mitosis


Diagnosis on excisions





The following table gives pointers to help distinguish histologically the various 'grades' of PT. It is emphasised that these criteria should NOT be taken as absolute but as a guide. It should be noted also that there are considerable variations in the literature as to what constitutes a 'cut off' point for a particular criterion.



  Benign Borderline Malignant
Pushing boundary Yes Usually Not usually
Stromal/epithelial balance Even Even Uneven
Stromal cellularity High High High
Variability of stromal cellularity Yes Yes Yes ++
Stromal mitoses /10 hpf < 5 5 - 10 >10


Benign PTs



The following sequence of images are from a benign PT:




Low power view of a PT. At this power all that can be stated is that it is a fibroadenomatoid lesion with an intracanalicular pattern.
Low power view of benign phyllodes tumour


The left hand image demonstrates well the leaf-like contours of the exaggerated intracanalicular growth pattern.
The right hand image shows increased (and variable) stromal cellularity.
Medium power view of an excision biopsy from a suspected phyllodes tumour Phyllodes tumour showing stromal hypercellularity


High power view of benign phyllodes tumour showing a stromal mitosis.
High power view of benign phyllodes tumour showing a stromal mitosis


The following sequence of images are from a borderline PT:




Macro view of a borderline PT. The cut surface shows exaggerated lobulation.
Low power view of benign phyllodes tumour


The left hand image demonstrates well the leaf-like contours of the exaggerated intracanalicular growth pattern.
The right hand image shows increased (and variable) stromal cellularity.
Medium power view of an excision biopsy from a suspected phyllodes tumour Phyllodes tumour showing stromal hypercellularity


Medium power view of a borderline PT with involvement of an excision margin.
High power view of benign phyllodes tumour showing a stromal mitosis




Malignant PTs



Macro of a malignant PT (wide local excision specimen) - black arrow indicates poorly demarcated but pushing edge of lesion; red arrow indicates degenerate central area
Macro of a malignant phyllodes tumour

This low power image demonstrates well the loss of stromal - epithelial balance in a malignant PT.
Macro of a malignant phyllodes tumour


The left hand image demonstrates well the infiltrating interface of the tumour with surrounding fatty breast tissue.
The right hand image shows stromal overgrowth.
Medium power view of an excision biopsy from a suspected phyllodes tumour Phyllodes tumour showing stromal hypercellularity


Selected views of phyllodes tumour with hpercellular stroma and infiltration of fat
Click on images for further detail


Phyllodes tumour - ifltrative margin Phyllodes tumour - infiltrative margin


Malignant Phyllodes Tumour:
The left hand image shows a focus of stromal osseous metaplasia.
It should be noted that heterologous stromal metaplasia such as this may occur in any of the 'grades' of PT but is more common in borderline and malignant lesions.
The right hand image shows a leaf-like structure with increased stromal cellularity and mitoses (arrows).
Medium power view of an excision biopsy from a suspected phyllodes tumour Phyllodes tumour showing stromal hypercellularity

Return to top of page