Invasive melanoma of the skin
Author:
Mikael Häggström [note 1]
Melanoma of the skin generally presents as a dark skin focality.
Fixation
Generally 10% neutral buffered formalin.
See also: General notes on fixation
Gross processing
Gross examination
Note:
- Color
- Well-defined or diffuse border
- Size
- Any elevation
Tissue selection
| <4 mm | 4 - 8 mm | 9 - 15 mm |
|---|---|---|
|
File:Tissue selection from skin excision 4-8 mm with suspected malignant lesion.png | File:Tissue selection from skin excision 9-15 mm with suspected malignant lesion.png |
In table above, each top image shows recommended lines for cutting out slices to be submitted for further processing. Bottom image shows which side of the slice that should be put to microtomy. Dashed lines here mean that either side could be used. Further information: Gross processing of skin excisions
Microscopic evaluation
Distinction from melanoma in situ
In melanoma in situ, melanoma cells are limited to the epidermis.[2]
- Further information: Evaluation of tumors
Further workup
- Suspected but not certain melanoma.
Generally perform immunohistochemistry with SOX10, whereby melanocyte nuclear pleomorphism is easier to see.[notes 1]
- Margins
Determine if the distance to any margin is greater or lesser than 3 mm.[3]
If melanoma, specify shortest distance to margin. Classification as radical can be made as follows:[4]
- 2 mm or more if a margin of normal tissue for sharply demarcated, small, superficially spreading or nevoid melanomas.
- 3 mm or more for ill-defined lentigo maligna melanoma in situ.
If non-radical, specify in which direction if possible.
If margins are difficult to determine, consider immunohistochemistry with SOX10 to better visualize melanoma nests.[notes 1]
- Depth
For invasive melanoma, measure the depth so as to be able to classify the T stage (following table by AJCC, 8th edition):[5]
- TX: Primary tumor thickness cannot be assessed (such as diagnosis by curettage)
- T0: No evidence of primary tumor (such as unknown primary or completely regressed melanoma)
| Stage | T category[5] | Thickness[5] | Ulceration[5] |
|---|---|---|---|
| Stage 0 | Melanoma in situ | ||
| Stage I | T1a | Less than 0.8 mm | No |
| T1b | Less than 0.8 mm | No | |
| >0.8 to 1.0 mm | Yes | ||
| T2a | >1.0 to 2.0 mm | No | |
| Stage II | T2b | >1.0 to 2.0 mm | Yes |
| T3a | >2.0 to 4.0 mm | No | |
| T3b | >2.0 to 4.0 mm | Yes | |
| T4a | >4.0 mm | No | |
| T4b | >4.0 mm | Yes | |
- Other parameters
Optionally, the following parameters can be given:[6]
- Further information: Evaluation of tumors
Report
Most important entries:
- Melanoma area dimensions (width x width)[7]
- Depth or most distant invasion of melanoma cells.[7]
- Radicality,[7] mainly into either of the following:
- >3 mm : "Clear margins" (or: "Clear margins at over __ mm")((or the exact distance thereof)).))
- <3 mm but not continuous with edge: "Close margins at __ mm at (location). [[Locations are mainly the deep edge, or the (superior/inferior/medial/lateral) radial edge.]]." Numbers are generally given at an exactness of 0.1 mm.
- Continuous with margin: "Not radically excised at (location)."
See also: General notes on reporting
Notes
- ↑ 1.0 1.1 SOX10 stains cell nuclei of melanocytes.
- Miettinen, Markku; McCue, Peter A.; Sarlomo-Rikala, Maarit; Biernat, Wojciech; Czapiewski, Piotr; Kopczynski, Janusz; Thompson, Lester D.; Lasota, Jerzy; et al. (2015). "Sox10—A Marker for Not Only Schwannian and Melanocytic Neoplasms But Also Myoepithelial Cell Tumors of Soft Tissue ". The American Journal of Surgical Pathology 39 (6): 826–835. doi:. ISSN 0147-5185.
- ↑ For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.
- ↑ The excision example shows a superficial basal cell carcinoma.
Main page
References
- ↑ There are many variants for the processing of skin excisions. These examples use aspects from the following sources:
- . Handläggning av hudprover – provtagningsanvisningar, utskärningsprinciper och snittning (Handling of skin samples - sampling instructions, cutting principles and incision. Swedish Society of Pathology.
- For number of slices and coverage of lesions, depending on size. - Monica Dahlgren, Janne Malina, Anna Måsbäck, Otto Ljungberg. Stora utskärningen. KVAST (Swedish Society of Pathology). Retrieved on 2019-09-26.
- For slices towards the pointy ends to determine radicality, which can be parallel to the slices through the lesions (shown), or as longitudinal slices that go through each pointy end. - . Dermatopathology Grossing Guidelines. University of California, Los Angeles. Retrieved on 2019-10-23.
- For microtomy of the most central side at the lesion - "The principles of mohs micrographic surgery for cutaneous neoplasia
- With a "standard histologic examination" that, in addition to the lesion, only includes one section from each side along the longest diameter of the specimen.
- It also shows an example of circular coverage, with equal coverage distance in all four directions.
- The entire specimen may be submitted if the risk of malignancy is high. - . Handläggning av hudprover – provtagningsanvisningar, utskärningsprinciper och snittning (Handling of skin samples - sampling instructions, cutting principles and incision. Swedish Society of Pathology.
- ↑ . Melanoma in situ (stage 0). Cancer Research UK. Last reviewed: 27 Jun 2019
- ↑ Definition of "thin margin": Wolf, Y.; Balicer, R.D.; Amir, A.; Feinmesser, M.; Hauben, D.J. (2001). "The vertical dimension in the surgical treatment of cutaneous malignant melanoma – how deep is deep? ". European Journal of Plastic Surgery 24 (2): 74–77. doi:. ISSN 0930-343X.
- ↑ Page 406 in: Klaus J. Busam, Richard A Scolyer, Pedram Gerami (2018). Pathology of Melanocytic Tumors . Elsevier Health Sciences. ISBN 9780323508681.
- ↑ 5.0 5.1 5.2 5.3 Gershenwald, Jeffrey E.; Scolyer, Richard A.; Hess, Kenneth R.; Sondak, Vernon K.; Long, Georgina V.; Ross, Merrick I.; Lazar, Alexander J.; Faries, Mark B.; et al. (2017). "Melanoma staging: Evidence-based changes in the American Joint Committee on Cancer eighth edition cancer staging manual
". CA: A Cancer Journal for Clinicians 67 (6): 472–492. doi:. ISSN 00079235., citing
Amin MB, Edge SB, Greene FL, et al, eds. AJCC Cancer Staging Manual. 8th ed. New York: Springer International Publishing; 2017:563‐585). - ↑ Rees, Jonathan; Viros, Amaya; Fridlyand, Jane; Bauer, Juergen; Lasithiotakis, Konstantin; Garbe, Claus; Pinkel, Daniel; Bastian, Boris C (2008). "Improving Melanoma Classification by Integrating Genetic and Morphologic Features ". PLoS Medicine 5 (6): e120. doi:. ISSN 1549-1676.
- ↑ 7.0 7.1 7.2 . An Example of a Melanoma Pathology Report. Melanoma Foundation. Retrieved on 2019-09-24.
Image sources