Skin

Background

Skin biopsies are frequently undertaken to investigate or remove a range of lesions. Specimens can be punch and shave biopsies, curettings or skin ellipses. Radical dissections that include lymph nodes may be received in advanced disease. 1-3 Dissection and sampling of skin specimens are important factors in accurate evaluation of surgical margins. 4-7


Record the patient identifying information and any clinical information supplied together with the specimen description as designated on the container. See overview page for more detail on identification principles.

Fresh tissue received
  • No
    • Non-routine fixation (not formalin), describe.
  • Yes
    • Special studies required, describe.
    • Ensure samples are taken prior to fixation.
      • Immunofluorescence 7
      • Flow cytometry
      • Microbiology
      • Cytogenetics
Intraoperative consultation
  • Not performed
  • Performed, describe type and result
    • Frozen section
    • Imprints
    • Other, describe

See general information for more detail on specimen handling procedures.

Inspect the specimen and dictate a macroscopic description.

External InspectionBack to top


Orientate and identify the anatomical features of the specimen.

An annotated permanent record of the specimen such as a drawing or photograph tmay be helpful when correlating the microscopic appearances.

Describe the following features of the specimen: 3-5

Procedure/specimen type

​Record as stated by the clinician.

Possible options
  • Excision
    • Ellipse, with orientation
    • Ellipse, without orientation
    • Polygonal or irregular
    • Wedge
  • Punch
  • Shave
  • Re-excision
  • Curette
  • Incision
  • Other
    • Moh's specimens
    • Scalp biopsies for alopecia
    • Nail bed biopsies
    • Other, describe

Specimen orientation

Record additional orientation or designation provided by operating clinician:

Orientation markers

Record additional orientation or designation provided by operating clinician:

  • Absent
  • Present
    • Method of orientation (e.g. suture, incision)
    • Describe orientation of the marker at cut-up (e.g. 12 o'clock)
    • Record any coloured inks applied and to which margin
    • Describe any dermoscopically identified areas

Specimen integrity

  • Intact
  • Disrupted/fragmented, describe
    • Number of pieces

Anatomical components present

Possible options
  • Epidermis
  • Dermis
  • Subcutis
  • Skeletal muscle
  • Cartilage
  • Bone
  • Large vessels
  • Large nerves

Specimen size (mm)

  • In three dimensions 3-5

Lesion

  • Absent
  • Present
    • Number; if more than one lesion, designate and describe each separately noting the distance between each lesion.

Lesion size (mm)

  • In three dimensions 3

Distance to margins (mm)

  • Distance of lesion to closest margin
  • Specify margin if orientated

Lesion description

Primary lesion
  • Macule
  • Papule
  • Vesicle
  • Bullae
  • Nodule
  • Plaque
  • Scar
  • Ulcer
  • Cyst
    • Describe contents
Secondary effect
  • Keratotic
  • Ulcerated/ulceration
    • Maximum dimension
  • Pigmented, describe colour(s) and variability
    • Uniform
    • Variegated
  • Roughened
  • Papillomatous
  • Skin-covered
  • Telangiectasia
  • Haemorrhagic
  • Necrotic
  • Colour, describe
  • Border
    • Smooth
    • Irregular
    • Distinct
    • Indistinct

DissectionBack to top


Small specimens
  • No dissection is required for shave biopsies, curettings and punch biopsies <3mm.
  • Punch/shave biopsies >3mm should be bisected.
  • Ellipses of skin can be serially sectioned transversely at 2-4mm intervals. 3,4
  • Usually, lip biopsies will be wedge-shaped and can be sectioned coronally at 3mm intervals to assess the distance of lesions to both lateral margins. Alternatively, dissect sagitally at 3mm intervals with longitudinal or shave sections at both lateral margins. See Head and neck > lip resection protocol for more detail.
Orientated specimens

The method of orientation (e.g.suture) and what is indicated (e.g. superior margin) should be recorded. Its placement at the time of macroscopy should also be recorded. In many laboratories the suture is generically placed at the 12 o’clock position and the specimen is painted along one margin as a minimum. The protocol shown in the illustration above uses three different coloured inks enabling clear identification of the four quadrants.

Please note painting protocols differ between laboratories.

Large specimens
  • Large specimens, 50-100mm, will require targeted sectioning guided by visual inspection. The margins of oriented specimens may be painted with ink. 
  • Record colour of inks applied and their corresponding margins.
  • Section transversely (“breadloaf”) and lay out slices in sequential order to demonstrate maximum depth of the lesion and its relationship to margins. Photograph and record a block allocation key if required.
  • One method for very large specimens, >100mm, is to section radially round the perimeter of the lesion, then bread-loaf as for other specimens. Inspect carefully for multiple/multifocal lesions, lymph nodes, large nerves, blood vessels and attached tissues (e.g. salivary gland, bone and cartilage). Photograph to record a block allocation key.
  • Record the plane of dissection in orientated specimens or indicate in a diagram or photograph of the dissected specimen.

Internal InspectionBack to top


Describe the cut surface appearance including the following items:

Lymph nodes (if present)
  • Sentinel lymph nodes
  • Regional lymphadenopathy

Retrieved from resection specimen

  • Describe site(s)
  • Number retrieved

Separately submitted

  • For each container, record specimen number and designation
  • Collective size of tissue in three dimensions (mm)
  • Number of grossly identified lymph nodes submitted
  • Maximum diameter of each (mm)

If tumour macroscopically involves any lymph nodes, record:

  • Number of macroscopically-involved nodes out of total number of lymph nodes retrieved
  • Maximum dimension of largest metastasis
  • Note any visible extranodal spread;and its proximity to the surgical margin

Photograph the dissected specimen if required.

ProcessingBack to top


Specimens <10mm

Submit all tissue for processing. 3 Biopsy pads or similar are required to prevent loss of tissue during processing.

Specimens >10mm

Serially section the specimen sequentially to demonstrate maximum depth of the lesion and its relationship to the margins. A photograph of the dissected specimen may be useful and can facilitate block identification.

It is recommended that most, or all, of the lesion is examined focusing on parameters which may upstage the tumour or affect prognosis.

The extent of sampling should take into account the following factors of the lesion:

  • Maximum thickness 3
  • Any unusual features
  • Heterogeneous areas 3
  • Areas of ulceration
  • Proximity to the margins 3 (sampling of polar margins is undertaken at the discretion of the laboratory but is recommended if the lesion is within 1-2mm of the margin) 4
  • Pay careful attention to the possibility of multiple lesions in large specimens. Each lesion  must be sampled as well as the area between lesions to determine if truly separate lesions are present
  • For large lesions with prior biopsies, the earlier report may also indicate a need for greater sampling e.g. where there is perineural spread, lymphovascular invasion etc.
  • Keratin may need to be trimmed to allow hyperkeratotic lesions to fit in cassettes.
Melanocytic lesions including congenital naevi

Additional targeted sampling of the following is recommended:

  • Darker areas
  • Pale possible regressed areas
  • Heterogeneous foci
  • Crusted foci
  • Separate smaller (satellite) lesions
  • Ulceration/erosion

Ink marking will assist in correlating areas of dermatoscopic concern at subsequent microscopic examination.

Pigmented lesions >100mm

One suggested method is to submit all radial sections from the perimeter of the specimen. Submit representative or alternate sections from the remainder of the bread-loafed specimen using the targeted sampling described for large specimens.

Atypical melanocytic lesions and melanomas

Where the specimen is a macroscopically atypical melanocytic lesion or previously diagnosed on biopsy as melanoma, submit all sections of the whole lesion. Where the edge of the lesion is indistinct the whole specimen should be embedded including the poles from the long axis.

Skin re-excisions for melanoma

Sample any macroscopic residual tumour and separate pigmented lesions. More sampling is suggested where there was microscopic perineural invasion, neurotropism, extensive regression, amelanotic tumour, lymphovascular invasion, satellites, angiotropism in the original specimen.

No clear recommendation exists but in the absence of a previous positive margin and no macroscopic abnormality, the minimum regime is to sample the specimen in its shortest transverse axis, incorporating the area from where the scar 3 appears to the margins. This can generally be achieved in 1-4 cassettes. 8,9

  • Record a diagram of inking and sampling of orientated re-excision specimens.
Lymph nodes (when present)

No clear recommendation exists. One approach is to submit all lymph nodes <10mm whole. Lymph nodes >10mm may be "bread-loaf" sectioned into 3-5mm slices and nodes macroscopically suspicious for metastases sampled. 10

See Sentinel and regional lymph nodes -melanoma for more detail.

Levels and additional stains will be required routinely on skin punch biopsies <3mm in maximum dimension. Routine special staining with periodic acid Schiff’s diastase (PAS-D) will be required on inflammatory cases. Laboratories usually have procedures for communicating these requirements (e.g. notation on the cassette, different coloured cassettes) before processing.

Record details of each cassette.

An illustrated block key similar to those provided below may be useful.

Block allocation keys

Small specimens
Cassette id
Site
No. of pieces
A-B
Skin, all tissue submitted
 
Large specimens
Cassette id
Site
No. of pieces
A
Lesion, point of deepest invasion
 
B-C
Margins
 
D
Lesion, at max. thickness
 
E+
Lesion, representative sections
 
Melanoma/atypical melanocytic lesions
Cassette id
Site
No. of pieces
A-B
Lesion (or whole specimen) all sections
 
Melanoma re-excisions
Cassette id
Site
No. of pieces
A-D
Representative sections including scar to margins
 

Acknowledgements

Dr Craig James for his contribution in reviewing and editing this protocol.

ReferencesBack to top


  1. Rapini RP. Obtaining a skin biopsy specimen and interpreting the results. Dermatol Clin 1994;12(1):83-91.
  2. Sardi JR. The histologic grossing and reading of wedge-shaped specimens from malignancies taken from the oral lips. J Dermatol Surg Oncol 1979;5(3):219.
  3. Scolyer R, Ellis D, Heenan P, James C, Kelly J, McCarthy S, Stevens G, Swain S and Thompson J. Primary cutaneous melanoma structured reporting protocol, The Royal College of Pathologists of Australasia, Surry Hills, NSW, 2010.
  4. Slater D and Walsh M Dataset for the histological reporting of primary cutaneous malignant melanoma and regional lymph nodes, The Royal College of Pathologists, London, 2014.
  5. Slater D, Biswas A, Cerio R, Cook M, Fallowfield M, Furness P, Kavanagh G and Walsh M. Tissue pathways for inflammatory and non-neoplastic dermatoses and non-neoplastic lesions, The Royal College of Pathologists, London, 2008.
  6. Weinstein MC, Brodell RT, Bordeaux J and Honda K. The art and science of surgical margins for the dermatopathologist. Am J Dermatopathol 2012;34(7):737-745.
  7. Sleiman R, Kurban M, Abbas O. Maximizing diagnostic outcomes of skin biopsy specimens. Int J of Dermatol. 2013;52(1):72-8.
  8. Martin HM, Birkin AJ and Theaker JM. Malignant melanoma re-excision specimens--how many blocks? Histopathology 1998;32(4):362-367.
  9. Johnson and Sviland. Is extensive histological examination of wide excision specimens necessary following a diagnosis of melanoma? Histopathology 1998;32(4):379-380.
  10. Australian Cancer Network Melanoma Guidelines Revision Working Party. Clinical Practice Guidelines for the Management of Melanoma in Australia and New Zealand, Cancer Council Australia and Australian Cancer Network, Sydney and New Zealand Guidelines Group, Wellington, 2008.