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
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
12 and 3 o'clock margins -red,
6 and 9 o'clock margins -blue
A diagram of the pertinent anatomy showing the location of the sutures
and ink marking is useful for guaranteeing the orientation of the
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
Not more than 3 sections should be processed in each cassette, to make
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
The two polar ends of the skin ellipse should be placed in two
designated cassettes depending on whether the specimen is clinically
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
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
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
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