The role of preoperative
biopsy is to distinguish a benign from a malignant tumour. A
specific subtyping is less important at this stage.
FNA, frozen section or trucut biopsy should be interpreted by
experienced pathologists.
The tumour may have heterogenous areas (fibrous pseudocapsule and
surrounding reactive tissue), which may lead to sampling errors.
Trucut biopsy and FNA can be useful in establishing whether there is local
recurrence of the tumour.
Excisional biopsy - The lesion is usually 'shelled out' and the
margins are often inadequate. A thin rim of normal tissue is included in
some cases.
To have an adequate incisional biopsy is the most reliable way
to diagnose soft tissue tumour.
If the tumour is malignant a definitive surgery should be performed
immediately including the biopsy site and tract to prevent
possible spread of tumour from the biopsy site.
1. Grade of the tumour
2. Size
3. Positive margin or distance of the tumour from the nearest
margin.
4. Depth of the tumour
5. Extent of necrosis
6. Relation of the tumour to other important structures
7. Cytology and growth pattern
|
|
|
GROSS EXAMINATION:
If the specimen is orientated, it will be useful to draw a diagram.
Ink all the margins (use minimum 2 colours).
Gross
examination includes:
Detailed
description of the tumour:
-Size
-Colour
-Extent of necrosis ( more than 50% necrosis indicates bad
prognosis.)
-Mucoid slimy areas,
-Gritty areas of calcification
-Cystic changes ,
-Areas of haemorrhage,
Distance of
the tumour from various margins and vital structures.
(Clearly describe the fascial margins and the surgical cut margins.)
|
BLOCKS:
It is
essential to get the right section.
Sections are taken from -
-Tumour
Ideally one section of the tumour taken for every centimeter of
the maximum diameter of the tumour.
-Margins
-Viable tissue with necrosis.
-Tumour with surrounding structures.
-Any unusual area. |
Fresh tissue should be kept for further studies-
1. Electron microscopy
(tissue kept in glutaraldehyde)
2. Cytogenetics
3. Flow cytometry
4.
Molecular studies
|
|
