Clark's level is a

staging system Cancer staging is the process of determining the extent to which a cancer has developed by growing and spreading. Contemporary practice is to assign a number from I to IV to a cancer, with I being an isolated cancer and IV being a cancer that ha ...

, which describes the level of anatomical invasion of the

melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ( ...

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

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

and

Massachusetts General Hospital Massachusetts General Hospital (Mass General or MGH) is the original and largest teaching hospital of Harvard Medical School located in the West End neighborhood of Boston, Massachusetts. It is the third oldest general hospital in the United Stat ...

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 hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...

(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 Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Basilar papilla, a sensory organ of lizards, amphibians and fish * Dental papilla, in a developing tooth * Dermal papillae, part of ...

and

reticular 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 4: Invasion into the

*Level 5: Invasion into subcutaneous tissue.

National usage

In the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

, the current staging system adopted by the

American Joint Committee on Cancer {{Short description, Organization standardising cancer staging 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 Joi ...

(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,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...

References

{{reflist

External links

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

External links