1. Excisional Biopsy-
In
this procedure the entire lump or tumour is excised and a margin of
normal tissue is present around the lesion together with subcutaneous
fat.
2. Incisional Biopsy-
A portion of the lump is removed surgically. This is most commonly
used for tumours of the skin.
A. Shave Biopsy :
In this procedure the surface portion is sliced off with a blade.
B. Curette method:
In this procedure the surface of the lesion is scrapped off.
These methods are done to remove small growth and to confirm its
nature.
C. Punch Biopsy:
This procedure is done to sample skin rashes and small masses. A small
cylinder of skin is removed.
The clinician's
responsibility is to provide an appropriate biopsy which is
untraumatised and appropriately fixed.
INFORMATION REQUIRED IN THE REQUEST FORM:
1. Patient identification- Name ; Age ; Hospital number; Gender
2. Name of the clinician/surgeon
3. Date of procedure
4. Procedure- Excisional biopsy, Incisional biopsy etc
5. Anatomic site of specimen
6. Clinical information (see below)
7. Clinical diagnosis
CLINICIAN
MUST PROVIDE THE FOLLOWING CLINICAL INFORMATION:
Relevant
history :
I. Duration of lesion
II. Previous excision of the lesion
III. Family history of skin rashes or cutaneous neoplasm such as
melanoma
IV. History of immunosuppression (HIV infection, transplant
recipients, steroid and cytototoxic therapy.)
V. History of radiation exposure, arsenic, toxic chemical
VI. History of rheumatoid arthritis, diabetes mellitus, pregnancy
internal malignancy (eg, colonic carcinoma or renal cell carcinoma)
VII. History of travel to foreign countries
Relevant
findings:
I. Lesion number and distribution
II. Description of lesion -nature of pigmentation,colour, nature,
shape, outline, ulceration, haemorrhage.
(Note- Shape may be annular,figurate,gyrate or irregular)
III. Palpable quality of lesion (eg. hard, painful, non tender)
IV. Fixation to deeper tissue on palpation
GROSS
DESCRIPTION BY HISTOPATHOLOGIST:
The histopathologist
should provide a vivid macroscopic description so that while reading
the report one can actually visualise the specimen and lesion.
I. Specimen-
1.Shape and type of specimen- (Eg. Ellipse, punch core, shave
fragments)
2.Fixed or unfixed
3.Number of pieces of tissue
4.Dimensions of specimen in millimetres (length, breath and
thickness). In case of small biopsies and punch biopsies maximum
diameter is noted.
5.If the specimen is marked with surgical suture, the position is
described in details.
II. Characteristics of the lesion-
1.
Dimensions-
Length and width of the lesion or diameter of the dominant nodule.
5. Surface
- intact or ulcerated , regularity and symmetry.
6. Margins
- sharp or ill defined, flat or elevated
7. Satellite nodules
with dimensions and measurement of distance from the main lesion and
nearest margin.
8. Identification
and measurement of the distance between the edge of the dominant
lesion and the nearest surgical margin (depending on type of specimen.
9. Description of any
other lesions
present (eg. scar, areas of pigmentation).
Configuration is the contour or outline of a single skin lesion
and is synonymous with shape.
Configuration:
A) Linear - in a line.
B) Arciform - in the form of an arc, curved. 1.
Arcuate: having an outline of a curved line or arc. 2.
Annular: ring-shaped 3. Serpentine: having an outline like a
serpent, coiled. 4. Polycyclic: having two or more rings or
whorls. 5. Targetoid: resembling a target, rings
within rings.
C) Circular - having an outline of a full circle without central
clearing. (Guttate - like a gutt or drop. Nummular or discoid -
having the shape and size of a coin or a disc.)
III. Tissue submitted-
A. Must mention whether the entire
tissue has been submitted for histopathological examination.
B. Tissue submitted for special studies-
(Eg . histochemical stains, immunohistochemistry, electron microscopy,
cytogenetics etc.)
Fixation of Skin Specimen:
Fixative for skin specimens is 10%
buffered formalin.Formalin
should be approximately 20 times by volume that of the specimen.
Direct
immunofluorescence -
To detect antibodies and/or complement localized in the skin . i)
Vesiculobullous diseases, e.g., bullous pemphigoid, pemphigus
vulgaris, and dermatitis herpetiformis. Biopsy specimen for direct immunofluorescence must be
taken from skin contiguous to a newly formed lesion. The
nonvesicular 'perilesional zone' should not be eroded or crusted.
ii) Vasculitis -Biopsy may be taken of the lesion itself
(must be an early lesion).
Electron
microscopy: Specimen may be placed in
modified Millonig's fixative or glutaraldehyde rather than in
formalin.
HANDLING
OF GROSS SKIN SPECIMEN:
(A
PRACTICAL GUIDE FOR RESIDENTS AND JUNIOR DOCTORS)
Excisional skin biopsies or formal
resections for melanocytic lesion and proven or suspected skin cancer
are usually sent to the laboratory with one margin appropriately
marked with an orientation suture.
It is important for the pathologist to evaluate the lateral and the
deep margins.
This will help the attending clinician to identify the specific site
of an existing tumour and its probable extent beyond the surgical
margin of resection.
Re-excision of the involved margin can be performed.
The specimens requiring orientation should be marked using standard
technique of painting.
Multiple colours allow identification of two short axis margins, two
long axis margins (denoted as 3, 6 , 9 and 12 o'clock margins) and the
deep margin.
( Eg.
12 and 3 o'clock margins -red,
6 and 9 o'clock margins -blue
and
deep
margin -black).
A diagram of the pertinent anatomy showing the location of the sutures
and ink marking is useful for guaranteeing the orientation of the
specimen.
The commonly employed substances used for marking of surgical margins
include Indian ink , alcian blue or commercial preparations.
Curetted specimens,incisional biopsies, shave biopsies and punch
biopsies do not require the margins to be inked.
All specimens from excisional biopsies should be sectioned
transversely in a 'sliced bread' pattern.
The first section should be taken from the centre of the lesion and
this should be followed by sectioning the whole specimen every 2 - 3
mm.
Not more than 3 sections should be processed in each cassette, to make
one block. (According to some dermatopathologists - One section
per cassette in case of Atypical Melanocytic Lesions ; One or two
sections in case of other tumours).
In specimens less than 10mm the entire lesion must be submitted for
histopathological examination or the entire specimen if the lesion
cannot be seen.
In excisional biopsies over 10mm containing melanoma , the entire
lesion is embedded.
In case of basal cell carcinoma and squamous cell carcinoma blocks are
taken from areas of maximum lesional thickness, ulceration and nearest
margins.
The two polar ends of the skin ellipse should be placed in two
designated cassettes depending on whether the specimen is clinically
orientated .
The polar ends are embedded and cut from the 'face down' aspect .
If the initial sections show malignant involvement , step levels can
be undertaken to assess clearance up to the extreme peripheral
margin. In a large circular specimen cruciate margins at 3, 6, 9, and
12 o'clock can be sampled.
One should always use a fresh, sharp blade to cut the specimen .
If the knife is blunt then the delicate melanocytes in the junctional
component of the lesion may be disrupted when the specimen is
sliced, causing problem in diagnosis.
Good quality thin sections are essential for accurate diagnosis.
Excisional biopsies of melanocytic lesions should not be sectioned by
cruciates because this makes interpretation of the architecture of the
lesion more difficult.
In specimens from vesicular diseases, the vesicles should be submitted
intact.
One should not cut through the vesicle under any circumstances.
Small excisional biopsies (upto 5mm) are submitted in toto.
Step-levels should be undertaken in case of severely dysplastic,
in-situ or any difficult melanocytic lesion.
Make sure that the punch biopsies are orientated on edge.
In re-excision specimen, if the original lesion was completely excised
and if there are no macroscopic residual lesion other than a scar ,
only one representative section is taken from the centre of the
specimen.
If the original lesion was incompletely excised or if any residual
tumour is evident in the re-excision specimen, then blocks are taken
every 2 - 3 mm through the whole scar and embedded for
histopathological examination.