Definition of Clark level of invasion
Clark level of invasion: A method for determining the prognosis (outlook) with melanoma. The method was devised by the pathologist Wallace Clark and measures the depth of penetration of a melanoma into the skin according to anatomic layer.
There are five Clark levels of invasion:
Another melanoma measurement system, that of Breslow thickness, named after its originator Alexander Breslow, is in wider use today. In it, invasive tumor thickness is used to predict 5-year survival. For example, a thickness of the melanoma of less than 1.0 millimeters is associated with a 5-year survival of 97% of patients whereas a tumor thickness of more than 8.0 millimeters is associated with 5-year survival of 32%.
Last Editorial Review: 9/20/2012
Back to MedTerms online medical dictionary A-Z List
Need help identifying pills and medications?
- Allergic Skin Disorders
- Bacterial Skin Diseases
- Bites and Infestations
- Diseases of Pigment
- Fungal Skin Diseases
- Medical Anatomy and Illustrations
- Noncancerous, Precancerous & Cancerous Tumors
- Oral Health Conditions
- Papules, Scales, Plaques and Eruptions
- Scalp, Hair and Nails
- Sexually Transmitted Diseases (STDs)
- Vascular, Lymphatic and Systemic Conditions
- Viral Skin Diseases
- Additional Skin Conditions