Clark's level is a staging system, which describes the level of anatomical invasion of the

melanoma Melanoma is the most dangerous type of skin cancer; it develops from the melanin-producing cells known as melanocytes. It typically occurs in the skin, but may rarely occur in the mouth, intestines, or eye (uveal melanoma). In very rare case ...

in the skin. It was developed by Wallace H. Clark Jr. at

Harvard University Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyma ...

and

Massachusetts General Hospital Massachusetts General Hospital (Mass General or MGH) is a teaching hospital located in the West End neighborhood of Boston, Massachusetts. It is the original and largest clinical education and research facility of Harvard Medical School/Harvar ...

in the 1960s.

Levels

Five anatomical levels are recognized, and higher levels have worsening prognostic implications. These levels are: *Level 1: Melanoma confined to the

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermal layer provides a barrier to infection from environmental pathogens and regulates the ...

(melanoma in situ) *Level 2: Invasion into the

papillary dermis The dermis or corium is a layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. It is divided in ...

*Level 3: Invasion to the junction of the papillary and reticular dermis *Level 4: Invasion into the reticular dermis *Level 5: Invasion into subcutaneous tissue.

National usage

In the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, the current staging system adopted by the

American Joint Committee on Cancer The American Joint Committee on Cancer (AJCC) is an organization best known for defining and popularizing cancer staging standards, officially the AJCC staging system. The American Joint Committee on Cancer (AJCC) was established in 1959 to formul ...

(AJCC) no longer considers Clark's level, because it is less prognostic and more subjective than other alternatives. However, it is a mandatory component for melanoma pathology in

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

References

{{reflist

Sources

Melanoma Staging Systems
National Cancer Institute. A resource on Clark's levels and Breslow's depth.
Original article from Breslow
Cancer res, 1969. Histopathology Melanocytic nevi and neoplasms Dermatologic terminology Cancer staging

Levels

National usage

See also

References

Sources